trinidad & tobago small building code (draft)
TRANSCRIPT
Content
FOREWORD 4
1 ADMINISTRATION OF THE CODE 5
1.1 Title 5
1.2 Scope 5
1.3 Application to build 51.3.1 General 51.3.2 Form of Application to Build 51.3.3 Approval in Part 7
1.4 Approvals 8
1.5 Inspections 81.5.1 Procedure 8
1.6 Special inspector 8
1.7 Completion certificate 9
1.8 Compliance 9
1.9 Alternate materials and types of construction 101.9.1 General 101.9.2 Standards 101.9.3 Application 10
2 TERMS AND DEFINITIONS 11
3 GENERAL CONSTRUCTION 12
3.1 Principle 123.1.1 Site preparation 123.1.2 Site clearance 133.1.3 Material storage 133.1.4 Batter boards 133.1.5 Driveways and paving 133.1.6 Earth works 143.1.7 Earthquake considerations 153.1.8 Hurricane considerations 213.1.9 Roofs. 303.1.10 Windows and doors 31
3.2 Design criteria 353.2.1 Conventional design 353.2.2 Engineered design. 373.2.3 Dead load. 39
3.2.4 Live load. 393.2.5 Roof load. 413.2.6 Lateral load design 413.2.7 Load factors. 443.2.8 Deflection. 45
3.3 Minimal requirements 463.3.1 Location on lot 463.3.2 Light 463.3.3 Ventilation 473.3.4 Minimum room areas 483.3.5 Ceiling height 523.3.6 Minimum passage 523.3.7 Sanitation 543.3.8 Toilet, bath and shower spaces 543.3.9 Glazing 593.3.10 Enclosed garages 613.3.11 Emergency escape and rescue openings 613.3.12 Exits 623.3.13 Landings on stairways 653.3.14 Pedestrian ramps 653.3.15 Stairways 653.3.16 Handrails 703.3.17 Guards 723.3.18 Foam plastic 723.3.19 Flame spread and smoke density 743.3.20 Insulation 743.3.21 Dwelling unit separation 743.3.22 Moisture vapour retarders 763.3.23 Protection against decay 773.3.24 Protection against termites 813.3.25 Site address 813.3.26 Flood resistant construction 813.3.27 Coastal high hazard areas. 83
3.4 Basic materials 853.4.1 Reinforced Concrete 853.4.2 Timber 903.4.3 Metal 90
4 FOUNDATIONS 92
4.1 General 924.1.1 Load bearing walls and columns 924.1.2 Reinforcement 92
5 VERTICAL STRUCTURES 98
5.1 Concrete and masonry 985.1.1 Masonry Block Walls 985.1.2 Columns, beams and shear panel structure 1165.1.3 Framed structure See next edition to be published 119
5.2 Timber 1215.2.1 Identification & Grade. 1215.2.2 Exterior walls. 1215.2.3 Interior load bearing walls. 1245.2.4 Interior non-bearing walls. 1245.2.5 Drilling and notching-studs. 124
5.2.6 Headers. 1255.2.7 Cripple walls. 1255.2.8 Wall bracing. 1265.2.9 Structure 1295.2.10 Cladding 129
5.3 Metal 1335.3.1 MS beams and profiles 133
5.4 Mixed construction 133
6 FLOOR SYSTEMS 136
6.1 Concrete floor slabs 1366.1.1 Layout 1366.1.2 Finishing 1436.1.3 Services 143
6.2 Timber 1456.2.1 Identification & Grade. 1456.2.2 General 1456.2.3 Floor sheathing 149
6.3 Metal 1506.3.1 MS steel beam 150
7 ROOF ASSEMBLIES 152
7.1 Roof structure 1527.1.1 Concrete roof structure 1527.1.2 Timber 1527.1.3 Metal 162
7.2 Roof covering 1657.2.1 Weather protection 1657.2.2 Materials 1667.2.3 Requirements for material roof covering 166
8 FIGURES 175
9 TABLES 178
10 NORMATIVE REFERENCES 179
FOREWORD
1.In the preparation of this code, extensive use has been made of the Parts of the CaribbeanUniform Building Code (CUBIC) which deals with small buildings. The CUBIC is at this time beingconsidered for revision and the management Committee for the revision project has elected to makeuse of the International Code Council Inc., of the U.S.A. in the provision of base documentation for therevision of CUBIC. In like manner for this code use has been made of the I.C.C. year 2000.International Residential Code Final Draft 1998.
2.The drafting of the code document has been managed by the Board of Engineering of Trinidad &Tobago, sponsored by the Joint Consultative Council in the Construction Industry and the InterimNational Physical Planning Commission with the support and active participation of the Trinidad &Tobago Bureau of Standards.
3.A committee has been meeting consistently for the past two years for the preparation of thisCode and comprises the following members.
The Committee, which has prepared this code, is comprised of:-
Mr. Fenrick De Four National Physical Planning Commission (Chairman)
Mr. Burnell Austin Ministry of Local Government
Mr. Stephen Basdeo National Emergency Management Authority
Mr. Kenrick Bethelmy Trinidad and Tobago Fire Services
Mr. Jack Bynoe Board of Architecture of Trinidad & Tobago
Mr. Peter Bynoe Trinidad & Tobago Institute of Architects
Dr. Richard Clarke Board of Engineering of Trinidad & Tobago
Mr. J. Holgar Hackshaw Land Settlements Agency
Mr. Adul Latiff John Donaldson Technical Institute
Dr. Jeffrey M. Phillips Board of Engineering of Trinidad & Tobago
Mr. Jean M. Picchiottino Board of Engineering of Trinidad & Tobago
Mr. Francis Pierre Sangre Grande Regional Corporation,
Ministry of Local Government
Mr. Edwin Yuk Low City Engineer, Port of Spain City Corporation
Mr. Ishmael A. Soobrattee Trinidad & Tobago Bureau of Standards (Secretary)
4.The first edition of this code [provides simple guidelines for the construction of small buildings(residential, office or light industrial) where use is made of concrete foundations, masonry block wallsand timber frame roofing.
5.Future editions of this code will cover all types of small buildings constructed with concrete,masonry, timber, metal or any combination of these
1 Administration of the code
1.1 Title
These provisions shall be known as the "Trinidad and Tobago Small Buildings Code" and shallreferred to herein as "This code".
1.2 Scope
1.2.1
The provisions in this code shall apply to the construction, alteration, movement, enlargement,repair, equipment, use occupancy, location, maintenance, removal and demolition of buildings, forsingle or multiple family residential or general purpose use of not more than two stories in height andwith a floor area of three hundred square metres or less.
1.2.2
This code is intended to provide minimum requirements to safeguard life, limb, health andpublic welfare. It calls for minimum requirements for building materials in common use and takes intoconsideration the need for protection against wind and earthquake.
1.2.3
Sufficient detail is provided to allow for the adequate preparation of plans for buildings undernormal environmental conditions. Regulatory authorities would deal with approvals on the basis ofadherence to the requirements of this code.
1.2.4
The builder/designer is advised to seek assistance from registered professionals in the designand construction of wind and earthquake resistant structures for buildings outside the scope of thiscode and/or for special application or other than normal environmental conditions.
1.3 Application to build
1.3.1 General
A person wishing to erect a building or structure, or to carry out a building operation of a smallbuilding as defined shall comply with the requirements of the Planning and Development of Land Actand also with the requirements of this Code.
1.3.2 Form of Application to Build
Three (3) sets of completed application forms and plans are to be provided. The plans shallinclude the following:
(1)A location plan, showing the location of the lot sufficient to identify the site. Streets should benamed and lots numbered where applicable.
(2)A site plan, normally at a scale of 1/100, 1/125, 1/200 or 1/250 showing the dimensions of thesite and its relationship to abutting lots, roads, public utilities and buildings grades and elevations asdescribed in (3); and the location of the proposed building in relationship to the site boundaries, whichare to be identified.
(3)Existing and proposed contours and levels of the site are to be shown. The levels must showthe relationship of the lowest floor of the building with the levels of the adjoining street and with theknown datum.
(4) Building plans to include:
I. Floor Plan to Metric Scale 1/50 and/or 1/100
To show:
- room sizes and designations (all dimensions finish to finish including plaster)
- positioning of doors and windows
- materials used in construction
- thickness of each wall (including plaster)
II. Elevations and Sections to Metric Scale 1/50 and/or 1/100
To show:
- roof heights (floor to ceiling) and pitch
- height of floor above ground
- positioning of doors and windows
- materials used in construction
III. Foundation Plan to Metric Scale 1/50 and/or 1/100
To show:
- foundation layout
- cross sections
- materials used in construction
IV. Structural details to Metric Scale 1/50 and/or 1/100
To show:
- details of beams
- details of columns
- details of slabs
- details of floors
- details of all walls
- all reinforcement details
- roof design and construction details
V. Plumbing
To show:
- water and waste isometrics
- location of inspection boxes
- location and details of grease traps
- sizes and slopes of the pipes used in the sewer lines
- details of septic tanks and soakaway
VI. Site drainage
To show:
- storm surface and roof water disposal
-All drawings shall be individually numbered for ease of reference. Revisions shall carry revisionnumbers.
-All drawings, specifications and accompanying data shall bear the name and address of theperson responsible for the preparation of the plans and documents.
1.3.3 Approval in Part
a)Where approval of a portion of a building is desired prior to the issuance of a permit for thewhole project, application shall be made for the complete buildings, and detailed plans for the whichimmediate approval is desired shall be filed with the Chief Building Officer.
b)Should a permit be issued for a part of a building, the holder of such permit may proceed withconstruction without the assurance that the permit for the entire building will be granted. The grantingof such permit will depend on the approval of the application including all requirements.
1.4 Approvals
1.4.1All construction plans specifications and associated reports required by these rules shouldconformed to this code and shall be approved by the Chief Building Officer before constructioncommences.
1.4.2No construction shall commence until the Chief Building Officer has issued a permit or awritten notice to proceed.
1.5 Inspections
1.5.1 Procedure
The Chief Building Officer is authorised to make the following inspections and either approve theportion of the works completed or shall notify the builder where such work does not meet with hisapproval:
(i) SETTING OUT
(ii) FOUNDATIONS BEFORE CONCRETING
(iii) STRUCTURAL FRAME AND ROOF
(iv) RING BEAMS FORM WORK AND REINFORCEMENT
(v) PLUMBING
(vi) SITE DRAINAGE
(vii) FINAL INSPECTION (OCCUPANCY CERTIFICATE)
1.5.2 All inspections shall be carried out by persons authorised as Building Inspectors or bysuitably qualified persons approved by the Chief Building Officer and appointed to carry out suchinspections.
1.5.3 Work shall not be done on any part of a building or structure beyond the point indicated ineach successive inspection without first obtaining the written approval of the Building Inspector. Suchwritten approval shall normally be given only after an inspection shall have been made of eachsuccessive step in the construction as indicated by each of the foregoing inspections whereappropriate.
1.5.4 If circumstances warrant, the Chief Building Officer in his discretion may waive inspection butthis does not absolve the owner and builder from the responsibility of any construction in contraventionof this Code.
1.5.5 Reinforcing steel or structural framework of any part of any building shall not be covered orconcealed in any manner whatsoever without first obtaining the approval of the Building Inspector orthe Special Inspector.
1.6 Special inspector
When site conditions, size or complexity of the work warrants, the Chief Building Officer mayimpose a condition on the permit requiring the owner to employ a Special Inspector for the inspectionof the structural framework, or any part thereof, and for the review of all plans relating to such work, asherein required.
(i) Buildings or structures or part thereof of unusual design or method of construction and withcritical structural connections.
(ii) Marine construction.
(iii) Major foundations and/or pile driving.
(v) Major site works.
(vi) Drainage and waste disposal.
Such Special Inspector shall be a Listed Professional with the relevant experience. The SpecialInspector shall ensure compliance with this Code and shall submit regular progress reports andinspection reports to the Chief Building Officer.
At the completion of the construction work or project, the Special Inspector shall submit aCertificate of Compliance to the Chief Building Officer stating that the work was done in compliancewith this Code and in accordance with the approved plan or plans. His duties shall end with thesubmission of such certificate.
1.7 Completion certificate
a) A new building shall not be occupied or a change made in occupancy or the nature of the useof a building or part of a building until after a Completion Certificate has been issued.
b) Upon completion of a building erected in accordance with approved plans and after finalinspection herein referred to, and - upon application, the Chief Building Officer shall issue a Certificatestating the nature of the occupancy permitted.
c) A temporary Completion Certificate may be issued for a portion or portions of a building, whichmay safely be occupied prior to final completion of the building.
1.8 Compliance
a) The issuance and granting of a permit shall not be deemed or construed to be a permit for, oran approval of, any violation of this Code.
b) The issuance of a permit upon approval of plans and specifications, shall not prevent the ChiefBuilding Officer from thereafter requiring the correction of errors on such plans and specifications, orfrom preventing building operations being carried on thereunder when in violation of this Code or anyRegulations applicable thereto.
c) When during the construction of the work carried out under the permit, from issuance of permitto issuance of the Completion Certificate, the Chief Building Officer reasonably believes that approvedplans are in violation of this Code, he shall notify the permit holder and the permit holder shall correctthe drawings or otherwise satisfy the Chief Building Officer that the design and/or working drawingsare in compliance with this Code.
d) Compliance with this Code is the responsibility of the permit holder until the issuance of aCompletion Certificate; at which time it shall become the responsibility of the owner.
e) The permit granted for the construction of the work shall be available at the construction siteduring normal working hours for inspection by the Building Inspector.
1.9 Alternate materials and types of construction
1.9.1 General
The provisions of this Code are not intended to prevent the use of types of construction ormaterials or methods of designs as alternates to the standards herein set forth. Such alternates shallbe offered for approval and their consideration shall be as specified in this Section.
1.9.2 Standards
The types of Construction or materials or methods of design referred to in this Code shall be con-sidered as standards of quality and strength. New types of construction or materials or methods ofdesign shall be at least equal to these standards for the corresponding use intended.
1.9.3 Application
a) Any person desiring to use types of construction or materials or methods of design notspecifically mentioned in this Code shall file with the Chief Building Officer proof in support of claimsthat may be made regarding the safety and sufficiency of such types of construction or materials ormethods of design and request approval and permission for their use.
b) The Chief Building Officer shall approve such alternate types of construction or materials ormethods of design if it is clear that the standards of this Code are at least equalled. If, in the opinion ofthe Chief Building Officer, the standards of this Code will not be satisfied by the requested alternate,he shall refuse approval.
2 Terms and definitions
3 General construction
3.1 Principle
3.1.1 Site preparation
3.1.1.1 Preliminary investigation
Before any construction work commences, it shall be determined whether planning permissionand other approvals would be required from the competent (relevant) authorities. A preliminaryinspection of the site shall be undertaken so that preparation may be made for any problems or diffi-culties that may arise. This time should also be used to plan how the site will be organised so that alogical layout may emerge.
3.1.1.2 Checklist for site conditions
Completion of the checklist below will provide enough information about the site and itsconditions to permit construction to begin.
a) Has planning permission been obtained?
b) Is easy access to the site available?
c) Is there a surveyor's or topological drawing of the site?
d) Have the location of all boundary markers been found?
e) Are water, sewage disposal facilities and an electricity supply available on site?
f) Take note of the general topography of site and other physical conditions likely to causehazards.
g) Is there evidence of termite infestation in the soil or trees?
h) Will there be a need for the removal of large trees?
i) Is the area normally subject to land slippage?
j) Is there adequate natural provision for the removal of storm water i.e. collection of water as aresult of heavy rains or flooding.
k) Will construction endanger any of the public utility services?
l) Determine the height of the water table if appropriate.
m) Determine whether the soil is suitable for the construction of a soak-away pit.
n) Determine the ground floor datum.
o) Determine the depth of the foundation stratum.
q) Select suitable areas for stockpiling aggregate.
r) Select an area for the location of a concrete mixer or for the hand-mixing of concrete.
s) Select location of a materials storage shed.
t) Are their existing structures to be removed or altered?
Completion of the above checklist should highlight possible construction problems as well as therequirements of plant and materials. Where foundation problems are evident it is recommended thatan engineer or any other appropriate professional be consulted.
3.1.2 Site clearance
3.1.2.1
Care should be taken to preserve any trees on the site. Where it is necessary to remove anytrees, special care shall be taken to remove, totally, all roots and stumps of the felled trees as well asany of the other remains from the site.
NOTE There may be statutory limitations on the extent to which large trees may be removed.
3.1.2.2
The area where the building will be situated shall be stripped of topsoil. This material should bestock piled in a suitable area for later use during landscaping.
3.1.3 Material storage
3.1.3.1
Areas shall be allocated on the cleared site for the storage of materials. Coarse and fineaggregate for the mixing of concrete and mortar shall be placed in separate heaps in a location near tothe concrete mixer or concrete mixing area.
3.1.3.2
Cement, nails and finished materials (groove ply, PVC pipe, galvanised sheeting etc.) requiringprotected storage shall be stored in a shed, which is weather tight and has a wooden floor raised notless than four inches off the ground.
3.1.3.3
Reinforcement steel shall be stacked off the ground to reduce corrosion.
3.1.4 Batter boards
The building shall be properly set out on the site according to the building plan. Batter boards,which are horizontal boards parallel to the sides of the building and supported by vertical boards driveninto the ground shall be erected in convenient locations near the four corners of the building, and tothese boards should be transferred the building lines and levels for the project.
3.1.4.1
The floor level is usually marked on the batter boards and used as a permanent reference. All walllines and levels shall be referred to these boards. Periodic checks shall be made to ensure that theseboards have not been shifted from their intended positions.
3.1.5 Driveways and paving
3.1.5.1
The driveways and paving dealt with in this section are those suitable for use as driveways andparking areas for private cars and light goods vehicles only. Driveways shall be not less than 3m wide.
3.1.5.2
The choice of flexible (asphalt) or rigid (concrete) paving is largely influenced by the soilconditions at the site and the cost of driveway. Gravel driveways and paving are acceptable ifadequate drainage is available and if the gravel or crushed rock is reasonably hard, free from clay, andwould not be easily crushed by the light traffic. Adequate provision for drainage shall be made.
3.1.5.3
Where firm soils or rocks are present, any type of paving previously mentioned may be used.Where soft soils are present gravel or a flexible paving is recommended.
3.1.5.4
For all kinds of paving the topsoil shall be removed and replaced by a minimum of 150 mm ofcompacted, granular material.
3.1.5.5
For rigid paving, a concrete slab with a minimum thickness of 100 mm is required, reinforced bywelded wire mesh of minimum 100 mm2/m wide in both directions, placed 25 mm below the slabsurface. Construction joint shall be created every 5 m.
Note: A98, A142 and 150x150X4.5 BRC are acceptable.
3.1.5.6
For flexible paving a minimum thickness of 50 mm of asphalt (cold or hot mix) shall be appliedand compacted by roller on an approved and adequate sub base.
3.1.6 Earth works
3.1.6.1 Site topography
3.1.6.1.1
The natural topography of the land should be maintained and any excavation or back filling thatmust be carried out (and deemed as necessary) should be kept to a minimum. This is necessary tomaintain the natural vegetation, prevent landslides and flooding and preserve in general the naturalenvironment.
3.1.6.1.2
It is essential therefore that buildings should be constructed in such a manner to compliment thenatural topography of the site and not vice-versa.
3.1.6.2 Soil conditions
3.1.6.2.1
The characteristics of the site soil conditions shall be ascertained. If necessary, compaction shallbe carried out in order to improve the bearing value of the soil.
3.1.6.2.2
Where expansive clay is encountered or where problem conditions are present, professionaladvice shall be sought before planning the foundation.
3.1.6.3 Excavations
3.1.6.3.1
Excavations for foundations shall be carried out along the building lines to the depth of thefoundation stratum identified as suitable.
3.1.6.3.2
Excavations not exceeding 1.5 m in depth may generally be without planking and strutting, whichis a system of braced timber walls erected against the faces of the excavation to prevent collapse. Forexcavations exceeding 1.5 m the extent of planking and strutting necessary shall be determined by thenature of the soil and the location of the water table.
3.1.6.3.3
Where collapse of the side of excavation is anticipated, all excavation in excess of 1.5 m in depthshall be planked and strutted.
3.1.6.3.4
Where the foundation is in rock, it shall be excavated at least 50 mm to provide a key for thefoundations.
3.1.6.3.5
The bottom of all excavations shall be level and firm. Where loose materials are encountered,foundation bottoms shall be compacted by ramming.
3.1.6.3.6
Where excavations have been carried beyond their generally required depth, either by accident ordesign, the deep areas shall be back filled with compacted, adequate material or with Grade Econcrete (see table B-1).
3.1.6.4 Back filling
3.1.6.4.1
Back filling shall not be carried out in dry rivers, natural drains, where water flows after heavyrains and along thalwegs (lowest areas in valleys).
3.1.6.4.2
Back filling around foundation walls and under floor slabs shall be carried out using only suitable,selected materials. Unless the floor slab is reinforced to act as a suspended slab, the depth of fill shallnot exceed 1 m.
3.1.6.4.3
Suitable fill material may be brought to the site or obtained from excavated material, providedalways that such material is free of substantial amounts of clay or organic matter.
3.1.6.4.4
All backfill shall be well compacted in layers not exceeding 150 mm in thickness wherecompaction is by hand. Where mechanical compaction equipment is used, the thickness of layers maybe increased to 225 mm.
3.1.6.4.5
Where back filling under floor slabs on grade has been effected using hard core, a 50 mm layer ofsand shall be applied to the top of the compacted hard core to protect damp proof membranes frompuncture.
3.1.7 Earthquake considerations
3.1.7.1 Earthquake resistant construction
3.1.7.1.1 General
Trinidad and Tobago is in an earthquake zone and has experienced varying degrees of damagedue to earthquakes. It is therefore essential that buildings are designed and constructed so that theyhave some resistance to the shaking or lateral forces produced by earthquakes.
3.1.7.1.2 Effect of soil type
3.1.7.1.2.1
The type of soil at the site may have a significant effect upon the resistance of the building to anearthquake. However for buildings within the scope of this code the effect of the soil type is not sosignificant provided that the building is not constructed on loose saturated sands, which may liquefyduring an earthquake and cause collapse of the building.
3.1.7.1.2.2
The earthquake may also, due to shaking of the ground, compact loose sand or fill material, and ifa building is constructed on such material, the building will be damaged.
3.1.7.1.3 Effect of high seas
Buildings on coastal areas may suffer due to high waves produced by earthquakes, and thereforethe siting of the building in relation to the sea level needs to be considered. Professional advice shalltherefore be sought in such cases.
3.1.7.1.4 Building shape
3.1.7.1.4.1
The success with which a building survives an earthquake is greatly affected by its shape in plan,the way the building is tied together and the quality of construction.
3.1.7.1.4.2
Most buildings with a simple rectangular shape with no projections (or only short projections)perform well under earthquake conditions provided the construction is adequate.
3.1.7.1.4.3
Long narrow buildings should be avoided by limiting the length to three times the width. If thebuilding must be longer, then it should be divided into separate blocks with adequate separation.Figure A1-1 illustrates desirable and undesirable plan shapes.
3.1.7.1.4.4
Rectangular buildings with well inter-connected cross walls are inherently strong and thereforedesirable.
Fig A1-1 Plan of building proportion
Separation of Blgsto improve resistance
Long undesirable plans
Desirable plans
Fig A1-2 Recommended location of wall opening
20
20
11
00
Floor level
Floor level
10
00
400400
1 800mm min Shear panel
Not acceptable opening location
Fig A1-3 Recommended location of wall opening for tow storey building
Ground level
First floor
First floor
Ground level
3.1.7.1.5 Appendages
Where buildings have decorative or functional additions or appendages such as window hoods,parapets and wall panels etc. extreme care must be taken to ensure that they are securely fixed, sincemany of such items tend to fall easily and may cause damage during an earthquake.
3.1.7.2 Rules for the construction of earthquake resistant buildings
It is recommended that the following rules be followed for the construction of buildings:
3.1.7.2.1 Masonry buildings
An important factor contributing to the earthquake resistance of masonry buildings is the detailingand placing of steel reinforcement. A registered professional should undertake the design of areinforced concrete frame building. The reinforcing guide given in this section therefore must only beused for simple single storey buildings constructed of approved quality masonry blocks. For theminimum quantities of reinforcing steel to be used refer to Clause Vertical Structures.
3.1.7.2.2 Timber buildings
There are two additional areas of concern with respect to timber buildings:
All corners and intersections must be adequately braced.
Earthquake and hurricane forces tend to remove timber buildings from their supports by shaking.Because of this sills shall be securely fastened to foundations.
3.1.7.2.3 Steel buildings
The natural ductility of steel protects the frame from severe damage. However, in many casesmasonry block walls are used and the precautions already listed for these walls will apply. The wallreinforcement must now be anchored by welding to the steel columns and beams, or the steel frameencased in concrete in which case the wall reinforcement can be tied into the concrete cage encasingthe steel frame.
3.1.7.3 Location of openings
3.1.7.3.1
The location and size of openings in walls have a significant effect upon the strength of a wall andits ability to resist earthquake forces.
3.1.7.3.2
Openings shall be located away from a corner by a clear distance of at least 1/4 of the height ofthe opening. It is recommended that the minimum distance be 400 mm.
3.1.7.3.3
The total length of the openings should not exceed 1/2 the length of the wall between consecutivecross walls (see figure A1-2).
3.1.7.3.4
The horizontal distance between two openings should not be less than 1/2 the height of theshorter opening (see figure A1-2).
3.1.7.3.5
For two storey buildings, the vertical distance from an opening to one directly above it shall not beless than 600mm, nor shall it be less than one half the width of the smaller opening.
3.1.8 Hurricane considerations
3.1.8.1 Hurricane resistant construction
3.1.8.1.1 General
3.1.8.1.1.1
It is very important in Trinidad and Tobago to be ever conscious of the fact that the region lies inthe hurricane belt. Because of this, hurricane resistant construction principles must be adhered to ifsafe buildings are to be erected. This section gives general principles for safe hurricane resistantdesign, and it is recommended that the details shown in these guidelines must be adhered in order toensure safe construction.
3.1.8.1.1.2
For the buildings within the scope of this document the areas most vulnerable to hurricane forcesare the roofs, windows, walls and appendages.
3.1.8.1.1.3
The underlying objective of hurricane resistant construction is to produce a building that will notcollapse during a hurricane. The building must be standing and its occupants should be safe.
3.1.8.2 Rules for the construction of hurricane resistant buildings
3.1.8.2.1 Building site
3.1.8.2.1.1
Buildings sited in exposed areas (e.g. on the brow of a hill or near coastal areas) are mostvulnerable, while those sheltered by natural topography are less vulnerable. Buildings sited in gulliesor riverbeds are very vulnerable as they are subject to severe damage by floods caused by the heavyrains, which often accompany a hurricane.
3.1.8.2.1.2
In siting the building, therefore, steep slopes and edge of cliffs should be avoided, as well as otherconditions such as steep sided valleys where exceptionally high wind speeds are found.
3.1.8.2.1.3
Tie beams should be constructed to reduce the untied height of the columns to a maximum of 3meters as shown in figure A1-6. It is advisable to seek professional assistance for such construction,unless otherwise designed for larger columns.
3.1.8.2.2 Timber buildings.
3.1.8.2.2.1
Because of the relatively light nature of a timber building, extra precautions shall be taken toprevent uplift. Care must therefore be taken to ensure that the entire structure is securely fastened tothe foundations.
3.1.8.2.2.2
The spaces between the supporting columns or piers may be filled in to reduce the uplift forces(see figure A1-6).
3.1.8.2.2.3
As far as timber walls are concerned, in addition to bracing corners in both directions, diagonalbraces or steel straps must be installed at the level of the top plate to provide rigidity of the corners atthat level (see figures A1-7 and A1-8).
Fig A1-4 Typical roof gable wall arrangement
frame of building
concrete ring beamroof reinforced
floor level
roof level
width of wall
Fig A1-5 Recommended method of construction on sloping sites
roof level
roof reinforcedconcrete ring beam
frame of building
floor level
200mm thk.r.c. blockwall
r.c. strip footing
200x300 r.c. tie beam
Ground slopes should be less than 15 degrees
existing grade
60
0m
mm
in90
0m
mm
in
Steep slopes more than 15 degrees
300x300 mm minr.c. column
r.c. footing
frame of building
200x300 r.c. tie beam
concrete ring beamroof reinforced
existing grade
floor level
roof level
r.c. footing
30
00m
mm
axi
mu
m
and less than 30 degrees
Note: Those sketches don't show the shear panels
Fig A1-6 In-fill panel between timber building supports
100 X 100 Timber sill
r.c. tie beam
200mm thick blockwork
Grade
Colomn may be 200 x 200mm reinforced concrete orblock work filled with concrete and 4 - 12mm rods8mm links - 200mm centers
Fig A1-7 Timber framing showing bracing
Horizontal bracing for cornersat wall plate level
50 x 100 wall plate
Uprights
25 x 150 sheating
Wall sill Brace corners bydiagonal bracings
Fig A1-8 Timber framing for wall
Wall sill
Dooropening
Windowopening
Wall sill is fixed to foundationwall by anchor bolts
Wall plate must be fastened and strappedto the top of uprights
The uprights are fixed tothe wall sill
Double uprightsat openings
Fig A1-9 Rafter/wall plate connections
Fig A1-10 Rafter/ ring beam connections
roof sheeting
roof battens
ceiling material
facia board
metal hurricane tieevery other rafter
timber wall plate
r.c. ring beam
150
225
50 x 150 timber rafterat 600mm centers
roof eave 900mm (max)
50 x 100 timber wall plate
12mm anchor boltat 1200mm centers(maximum)
r.c. ring beam
Fig A1-11 Wall plate connections and hurricane ties
Timber rafter
Infill concrete
r.c. ring beam
metal hurricane tieimbedded in ring beam
metal hurricane tie
Timber wall plate
Timber wall plate
Metal strap
Timber upright
Timber wall plate
Timber upright
Mortise
Tenon
3.1.8.2.3 Steel buildings
The principles for the design and construction of hurricane resistant steel buildings are:
3.1.8.2.3.1
Ensure that there are adequate numbers and sizes of foundation holding down bolts, and thatthey are all in place and properly fixed.
3.1.8.2.3.2
Ensure that there is adequate lateral support provided by cross bracing or horizontal ties or bycast in place concrete or masonry walls.
3.1.8.2.3.3
Where concrete walls or concrete masonry is used, the connections between the steel framesand the walls shall be provided.
3.1.8.2.3.4
Ensure that the fabricator's recommendations with regards to the construction of the roof and roofcovering are followed.
3.1.9 Roofs.
3.1.9.1
Roofs with pitch between 0 and 20° (or a slope between 0 % and 36 %) are more vulnerable touplift forces. It is recommended that roofs be constructed with a pitch between 20° and 40° (or a slopebetween 36 % and 84 %).
3.1.9.2
The aptitude to reduce uplift forces is affected by the shape of the roof in the following order fromthe most effective to the least effective:
a) Hip roof
b) Gable
c) Shed
3.1.9.3
Attention should be given to the location of fixings used for the roof cladding. It is necessary toprovide additional fixings at the roof edges and ridge, since high-localised pressures are produced inthese locations.
3.1.9.4
Roof overhangs also experience high local pressures and, where possible, these should be keptto a minimum or adequately strengthened.
3.1.9.5
Where buildings have covered patios or verandas, their roofs may be separate structures ratherthan extensions of the main building roof. A patio or veranda roof may be lost without endangering thesafety of the main roof.
3.1.9.6
The main roof must be securely fixed to the ring beam and ridge beams and details for achievingthis are shown in figures A1-9, and A1-10 and A1-11.
3.1.10 Windows and doors
Special attention must be paid to the installation of doors and windows, since the loss of a door orwindow during a hurricane will greatly alter the internal pressure of the building, thus adverselyaffecting its safety. For this reason, glazed windows and doors may be fitted with shutters.
Fig A2-1a Basic 1 or 2 level house type
Ground floor slab suspended
Shear panel
MasonrySuspended ground floor slabwith crawl space
Ground floor slab suspendedor on grade
Suspended first floor slabMasonry
or on grade
MasonryGround floor slab suspendedor on grade
Columns, beams & shear panel structure Framed structure
or on gradeGround floor slab suspended
Columns, beams & shear panel structureSuspended ground floor slabwith crawl space
Columns, beams & shear panel structureSuspended first floor slabGround floor slab suspendedor on grade
Suspended first floor slabGround floor slab suspendedor on grade
Suspended ground floor slabwith crawl space
Framed structure
Framed structure
Fig A2-1b Mixed 1 or 2 level house type
Ground floor slab suspended or slab on gradeSuspended first floor slabGround level columns, beams & shear panel structureFirst level masonry
Ground floor slab suspended or slab on grade
Ground level framed structureFirst level masonry
Suspended first floor slab
Crawl space framed structureSuspended ground floor slab
Crawl space columns, beams & shear panel structureFirst level masonry
Suspended ground floor slab
First level masonry
Sloping site
Flat site 2 levels
Fig A2-1c 1 or 2 level house, other combination
Suspended ground floor slabCrawl space framed structureFirst level metallic structure
Ground level framed structureFirst level timber
Suspended first floor slab
Crawl space columns, beams & shear panel structure
Ground level columns, beams & shear panel structure
First level cold formed steel
Suspended ground floor slab
First level timber
Suspended first floor slab
Suspended ground floor slab
One level timberGround floor slab suspendedor on grade
Shear panel
with crawl space
First level timber
Suspended first floor slabGround floor slab suspended
First level timber
or on grade
3.2 Design criteria
3.2.1 Conventional design
Buildings and structures, and all parts thereof, shall be constructed to support safely all loads,including dead loads.
Where different construction methods and structural materials are used for various portions of abuilding, the applicable requirements of this part for each portion shall apply.
3.2.1.1 Conventional building
Conventional construction shall be considered as building with acceptable shape of the figuresA2-1 (a to c) “1 and 2 level house type”.
All conventional construction shall be designed in accordance with this code.
3.2.1.2 Irregular building
Irregular buildings shall have an engineered lateral-force resisting system designed in accordancewith accepted engineering practice.
A building shall be considered to be irregular when one or more of the following conditions occur:
a) When exterior shear panels or reinforced frame is not in one plane vertically from the foundation tothe uppermost story in which they are required. (See Framed structure)
b) When a section of floor or roof is not laterally supported by shear panel or reinforced frame on alledges.
c) When an opening in a floor or roof exceeds the lesser of 3.60m or 50% of the least floors or roofsdimension.
d) When portions of a floor level are vertically offset.
e) When shear panel or reinforced frame is do not occur in two perpendicular directions.
f) When shear panel or reinforced frame are constructed of dissimilar bracing systems on any one-story level above grade.
3.2.1.3 Limit of this code.
When a building of otherwise conventional construction contains structural elements, whichexceed the limits of this code, those elements shall be designed in accordance with acceptedengineering practice.
Fig A2-2 Trinidad & Tobago winds
3.2.2 Engineered design.
3.2.2.1 General
Buildings shall be constructed in accordance with the provisions of this code as limited by theprovisions of this section.
3.2.2.2 Wind design.
The requirements in this document are based on design wind speed over open water atequivalent elevation of 10m average over 10 minutes with a recurrence of one in 50 year. (See figureA2-2 Trinidad and Tobago Winds)
Table 1 Design pressure for winds
Design pressure Trinidad
Central
Trinidad
Coastal
Tobago
Basic wind speed
Km/hr 72 92 101
Wall (horizontal load)kN/m2
0.70 0.90 1.00
Roof (uplift) kN/m2 1.00 1.30 1.45
3.2.2.3 Seismic design.
All buildings shall be constructed in accordance with the provisions of this section.
3.2.2.3.1 Seismic design category.
3.2.2.3.1.1 Ground acceleration
The requirements in this document are based on maximum ground acceleration associated with10% probability of occurrence in 50 years.
For Trinidad & Tobago 0.3 g
(g refers to the gravity and g = 9.81m/s2)
3.2.2.3.1.2 Amplification factor
Where the soil is 100% saturated (low land, reclaimed land, etc.) an amplification factor of 2 shallbe applied to the ground acceleration. See calculation for shear load.
3.2.2.3.1.3 Soil liquefaction
To prevent any soil liquefaction on the same type of land than above a special attention shall becarried out with an engineer specialist for the choice of the appropriate type of foundation. Seecalculation for shear load.
3.2.2.3.2 Weights of applied finishes
Dead load finishes shall not exceed 1 kN/m2 for roofs or 0.5 kN/m2 for floors.
Dead load finishes for walls above grade shall not exceed:
a- light-frame walls
0.75 kN/m2 for exterior
0.50 kN/m2 for interior
b- masonry walls.
2.50 kN/m2 for 150mm thick masonry wall.
3.80 kN/m2 for 200 mm thick masonry wall.
c- concrete walls.
4.10 kN/m2 for 150 mm thick concrete walls.
3.2.2.3.3 Height limitations.
The design applied to any construction is limited to two stories with a maximum of 9m to the top ofthe building.
3.2.2.4 Flood plain construction.
Buildings and structures constructed in flood prone areas as established in Fig. A2-1 shall bedesigned and constructed in accordance with Clause Flood resistant construction and Clause Coastalhigh hazard areas of Part "Minimal requirements".
3.2.3 Dead load.
The actual weights of materials and construction shall be used for determining dead load withconsideration for the dead load of fixed service equipment.
3.2.4 Live load.
The minimum uniformly distributed live load shall be as provided in Table 2.
Table 2 Minimum uniformly distributed live loads
Use Live loads (kN/m2)
Exterior balconies 5
Domestic floor / All rooms, stairs and corridors 1.5
Office floor 2.5
Small industrial and storage 5
Use Horizontal loads(kN/m)
Guard rails and handrails 1
Fig A2-3 Trinidad flood prone areas
3.2.5 Roof load.
Roof shall be designed for the live load indicated in Table 3.
Table 3 Minimum roof live loads (kN/m2)
Tributary loaded area for any structural members
Area (m2)Roof slope
0 to 20m2 20 to 55m2 over 55m2
Flat or rise less than (20°) 33%slope
1 0.75 0.6
Rise (20°) 33% to (45°) 100% 0.75 0.7 0.6
Rise greater than (45°) 100% 0.6 0.6 0.6
3.2.6 Lateral load design
3.2.6.1 Preamble
Wind and earthquake introduce horizontal loads in the superstructure that are transferred to thefoundation. We have to consider 2 steps:
a) Transfer of the horizontal load from
- wind to vertical wall and roof
- acceleration of mass located everywhere in the superstructure
to the appropriated wall or framed structure.
b) Transfer of the load from the top to the bottom of the wall or superstructure and the foundation.
According to this code
- horizontal transfer is done by horizontal diaphragm or horizontal beam
- vertical transfer is one by shear panel, cross, or framed structure
3.2.6.2 Diaphragm
Floor, roof or ceiling assemblies may be constructed with the necessary stiffness and load pathcontinuity to distribute lateral loads (wind and earthquake) to lateral support subsystems. In this role,floor, roof or ceiling surface act as horizontal beams (also called a diaphragm) spanning lateralsupports points.
Use of floor, roof or ceiling assembly, as a diaphragm requires both strength and stiffnessproperties and development of connections to transfer the diaphragm force.
Fig B6-1 Shear panel - Vertical core blocks
Part plan
Part elevation
Part elevation
In situ concrete
In situ concrete
400
In situ concrete
ground level
1 800
400
100
0
16
00
Minimum 800
2 diam. 12 every 2 rows
5 diam. 12
Shear panelin 2 parts
Shear panelin one part
150m
mm
in
Fig B6-2 Shear panel - Horizontal core blocks
Part plan
Part elevation
In situ concrete
In situ concrete
ground level
1 800
1600 max
2100 min
250mm min
Ring beam concrete and reinforcement 500
115
200
4 dia. 12mm
Part elevation
ground level
Ring beam concrete and reinforcement
Part elevation
ground level
150 min
Limit of openinglocation
6mm stirrup each 150mm
Shear panel in two parts
Shear panel in one part
L1 = 1000 min L2 = 2400 mm - L1
150m
mm
in
3.2.6.3 Shear panel
3.2.6.3.1 Concrete wall
A shear panel (see figures B-6-1 and B-6-2 Shear panel) is a portion or section of a 150mmexterior wall that performs the function of resisting lateral earthquake or wind forces.
3.2.6.3.2 Timber
See paragraph "Wall bracing".
3.2.7 Load factors.
All structures shall resist combined loads as follows;
3.2.7.1 Gravity
1.40 D + 1.70 L
3.2.7.2 Earthquake
a) 0.75 (1.40 D + 1.70 L +/- 1.87 E)
and
b) 0.90 D +/- 1.43 E
3.2.7.2.1 Shear load calculation
A simplified formula, for this code is
V = 0.05 x S x W total shear in kN
Whereas :
The 0.05 coefficient integrated the Z = ground acceleration, C = amplification factor due tostructure frequency, I = Importance factor =1 in this code and Rw = Ductility factor related with respectto the column design reinforcement used in the normal practice formula.
S = site factor
S = 1 For good soil (rock, gravel)
S = 1.2 For softer material (clay, fill )
S = 1.5 For deep alluvial deposits
S = 2.5 maximum for reclaimed land and saturated soils (due to the amplification factor)
W = total load in kN
3.2.7.3 Wind
1.40 D + 1.70 L + 1.75 W
Note:
D = dead load
L = live load
E = earthquake load
W = wind load
3.2.8 Deflection.
The allowed deflection of any structural member under the live load shall not exceed the followingvalues in Table 4
Table 4 – Maximum deflection authorised.
Rafters and purlins L/180
Interior walls and partitions H/180
Floors and ceilings L/360
All others structural members L/240
NOTES:
L = span length H = span height
3.3 Minimal requirements
3.3.1 Location on lot
3.3.1.1 Exterior walls.
Exterior walls with a fire separation distance less than 1.25m shall have not less than a one-hourfire-resistive rating. The one-hour fire resistive rating of exterior walls with a fire separation distanceless than 1.25m shall be rated for interior and exterior exposure. Projections beyond the exterior wallshall not extend more than 300mm into the fire separation distance. Projections extending into the fireseparation distance shall have not less than one-hour fire-resistive construction on the underside. Theabove provisions shall not apply to walls, which are perpendicular to the line used to determine the fireseparation distance.
3.3.1.2 Openings.
Openings shall not be permitted in the exterior wall of a dwelling with a fire separation distanceless than 1.25m. This distance shall be measured perpendicular to the vertical plane of the opening.
3.3.2 Light
3.3.2.1 Habitable rooms.
All habitable rooms shall be provided with an area to allow natural light to enter not less than 10percent of the floor area of such rooms.
3.3.2.2 Adjoining rooms.
For purpose of determining requirements of light, any room shall be considered as a portion of anadjoining room when at least one-half of the area of the common wall is open and unobstructed andprovides an opening of not less than 10% of the floor area of the interior room but not less than2.50m2.
3.3.2.3 Bathrooms.
Bathrooms, water closet compartments and other similar rooms shall be provided with an area toallow natural light to enter not less than 0.25m2.
3.3.2.4 Stairway illumination.
All interior and exterior stairways shall be provided with a means to illuminate the stairs, includingthe landings and treads.
Interior stairs shall be provided with an artificial light source located in the immediate vicinity ofeach landing at the top and bottom of the stairs.
Exterior stairs shall be provided with an artificial light source located in the immediate vicinity of thetop landing of the stairs.
3.3.3 Ventilation
3.3.3.1 Natural ventilation
3.3.3.1.1 Habitable rooms.
Natural ventilation shall be provided in all habitable room through windows, louvres or othernatural openings through the external wall to the outdoor air.
The minimum area of ventilation shall be not less than 15 percent of the floor area of such rooms.
3.3.3.1.2 Adjoining rooms.
For purpose of determining ventilation requirements, any room shall be considered as a portion ofan adjoining room when at least one-half of the area of the common wall is open and unobstructedand provides an opening of not less than 15% of the floor area of the interior room but not less than2.50m2.
3.3.3.1.3 Bathrooms.
Bathrooms, water closet compartments and other similar rooms shall be provided with aventilation area not less than 0.25m2.
3.3.3.2 Mechanical ventilation
3.3.3.2.1 Habitable rooms.
All habitable rooms shall be provided with the minimum ventilation rates of 30m3/hr for continuousventilation for every 12m2 of the floor area or part of such rooms.
This ventilation shall be through windows, doors or other natural openings through the externalwall from the outdoor air through a special 30m3/hr-air regulator.
3.3.3.2.2 Kitchen and bathrooms
All the air introduced into the house through the habitable rooms must be extracted in the roomse.g. kitchen, bathroom, toilet, washing room and other similar rooms have to be maintained indepression to create an air flow through the house.
The minimum exhaust airflow for each room is as follows
Kitchen 120 m3/hr
Bathroom 60 m3/hr
Shower 60 m3/hr
Toilet (WC) 30 m3/hr
Washing room and store room 30 m3/hr
This ventilation air shall be exhausted permanently and directly outside.
3.3.3.2.3 Internal doors
All internal doors have to be provided with air passages not less than 150 cm2.
Note: These passages can be provided with a bottom gap of 2 or 2.5cm under the door.
3.3.3.2.4 Minimum global ventilation
For each house or apartment the minimum ventilation rate is one volume of the habitable part ofthe house per hour.
3.3.4 Minimum room areas
3.3.4.1 Minimum area.
Every dwelling unit shall have at least one habitable room (living, sleeping, eating or cookingroom), which shall be not less than 12m2 of floor area.
3.3.4.2 Other rooms.
Other habitable rooms shall have a gross area of not less than 7.50m2.
3.3.4.3 Exception:
Kitchen not less than 5m2
Bathroom not less than 3m2and not less than 2m2 for the second one
Shower not less than 1.5m2
Toilet (WC) not less than 1m2
See figure A3-1 Minimum room sizes, A3-2 Typical furniture arrangement and A3-3 Typicalarrangement 7.5m2 room.
Fig A3-1 Minimum room sizes
2500mm minimum
3000mm
3464mm square
4800mm
4000mm
3464mm
3000mm
2500mm minimum
2739mm square
2739mm
1800mm min
2778mm
2143mm
1400mm min900mm min
750mm min
1667mm
1333mm
1732mm square
1732mm
2236mm
2236mm
Main room12m2 min
Other room7.5m2 min
Kitchen5m2 min
Bath.3m2 min
Shower1.5m2 min
WC1m2 min
800mm
1250mm min
Fig A3-2 Typical furniture arrangement
1333mm
1m2 min
12m2 minMain room
4000mm
WC
2143mm
1800mm min
5m2 minKitchen
2778mm
1667mm
750mm min
1.5m2 minShower
900mm mini
1400mm min
Bathroom3m2 min
3000mm
890mm
785mm
685mm
685mm
685mm
Entrance
Fig A3-3 Typical furniture arrangement - 7.5 m2 room
2500mm minimum
3000mm
Other room7.5m2 min
2500mm minimum
3000mm
3.3.4.4 Minimum dimensions.
Habitable rooms shall not be less than 2.50m in any horizontal dimension.
Exception: minimum
Kitchen 1.80m wide.
Bathroom 1.40m wide.
Shower 0.90m wide.
Toilet (WC) 0.75m wide and 1.25m long.
Corridor 1.00m wide.
Stair 1.00m wide.
3.3.4.5 Height effect on room area.
Portions of a room with a sloping ceiling measuring less than 1.50m or a furred ceiling measuringless than 2.15m from the finished floor to the finished ceiling shall not be considered as contributing tothe minimum required habitable area for that room.
3.3.5 Ceiling height
3.3.5.1 Minimum height.
3.3.5.1.1 Habitable rooms
Habitable rooms (living, sleeping, eating or cooking room) and basement shall have a ceilingheight of not less than 2.40m. See figures A3-4 Habitable room area
3.3.5.1.2 Other rooms
Other rooms e.g. corridors, bathrooms, toilet rooms and laundry shall have a ceiling height of notless than 2.15m.
3.3.5.1.3 Measurement
The required height shall be measured from the finish floor to the lowest projection from theceiling.
3.3.6 Minimum passage
The minimum passage for the access to the dwelling and each room shall be as follows
3.3.6.1 Main entrance
Almost one access door from outside shall be not less than 900mm wide and 2000mm high.
3.3.6.2 Habitable rooms and secondary rooms e.g. Store and laundry
All passage for the access from another room or from the corridor shall be not less than 785mmwide and 2000mm high
3.3.6.3 Other rooms e.g. Bathroom and toilet
All passage for the access from another room or from the corridor shall be not less than 685mmwide and 2000mm high
Fig A3-4 Habitable room area
2400mm
1500mm minimum
Habitable area
2.40m area
Room total area
2150mm lowest habitable part
Nota: 2.40m area >= 80% of habitable area
3.3.7 Sanitation
3.3.7.1 Toilet facilities.
Every dwelling unit shall be provided with a water closet or privy, lavatory basin, and a bathtub orshower.
3.3.7.2 Kitchen.
Each dwelling unit shall be provided with a kitchen area and every kitchen area shall be providedwith a sink.
3.3.7.3 Sewage disposal.
All plumbing fixtures shall be connected to a sanitary sewer or to an approved private sewagedisposal system.
3.3.7.3.1 Septic tank
The capacity of the septic tank shall be calculated on the basis of 500 litres of sewage per person,full time user.
The minimum capacity is 2,500 litres
The water table must be a minimum of 1 metre deepest than the septic tank.
See figure A3-11 for 2500 litres and A3-12 for 3200 litres septic tank.
See also "Code of Practice for the Design and Construction of Septic Tanks and AssociatedSecondary Treatment and Disposal System" TTS 16 80 400: 1986.
Note: The above figures complied with this code.
3.3.7.3.2 Soak-away pit
See figure A3-13
The water table must be a minimum of 1 metre deepest than the soak-away.
3.3.7.3.3 Draining trench
Where is impossible to make a soak-away, a draining trench shall be used See figure A3-14
3.3.7.4 Water supply to fixtures.
All plumbing fixtures shall be connected to an approved water supply.
Kitchen sinks, lavatory basins, bathtubs, showers, bidets, laundry tubs and washing machineoutlets shall be connected to the water supply system.
3.3.8 Toilet, bath and shower spaces
3.3.8.1 Space required.
Fixtures shall be spaced as per Figure A3-5 Toilet, bath and shower spaces required.
3.3.8.2 Bathtub and shower spaces.
Bathtub and shower floors and walls shall be finished with a smooth, hard and non-absorbentsurface. Such wall surfaces shall extend to a height of not less than 1.80m above the floor.
Fig A3-5 Toilet, bath and shower space required
min 50mm
Clearance min 600mm
Lavatories
ShowerTub
Tub
Tub Water closetor bidet
Wall
min 375mm min 300mm
Clearance in front of900mm min
min 900mm
clearance mini. 600mm
min 100mm
opening 600mm min
min 100mmmin 100mm
Fig A3-11 Septic tank 2500 litres - 5 persons maxi
Ventilation pipe 100mmCleanout 100mm
Sewage inletslope 2.5% (1 in 40)
dia 12mm every 200mm
dia 12mm every 200mmboth directions
8 dia 10mm
6 dia 10mm
75
590 100
1210
900
215
0
150
100
2059
2365
900
4 5 ° 408
900
121
0
900
4 dia 12x 2400mm every 2 rows
All concrete blocks filled with concrete
1 600
inside waterproof liner
500 1462
1192
400
Outlet
Tie beam
and tie beam
or boundarymin 1500mm/building
min
1500
mm
Inspection dia 300mm
Fig A3-12 Septic tank 3200 litres - 8 persons maxi
1600
4084 5°
900
150
2150
All concrete blocks filled with concrete
100
and tie beam4 dia 12x 2500mm every 2 rows both directions
dia 12mm every 200mm
Tie beam
Outlet
100
inside waterproof liner
dia 12mm every 200mm
slope 2.5% (1 in 40)Sewage inlet
900
1192
550 1657
75 400
8 dia 12mm
6 dia 12mmCleanout 100mm
Ventilation pipe 100mm
1072
1376
2295
2600
1376
1072
550
950
950
652
Inspection dia 300mm
min
1500
mm
min 1500mm/buildingor boundary
FIG A3-13 Soak-away
FIG A3-14 Draining trench
Inlet
Natural sandvein
25mm stone
50mm flat silica stone
dia. 1400mm
1700 square
1100
(porous layer)
min 1000mm/boundarymin 2500mm /building
Top soil and vegetation
Inlet
Top soil and vegetation Perforated 100mm pipe
1200
150
400
650
10 metres minimum
Natural sand vein
25mm stone
general slope 2% (1 in 50)
500
min 2500mm /building min 1000/boundary
3.3.9 Glazing
3.3.9.1 Identification.
Each pane of glazing installed in hazardous locations shall be provided with a manufacturers orinstallers label, designating the type and thickness of glass and the safety glazing standard with whichit complies, which is visible in the final installation. The label shall be acid etched, sandblasted,ceramic-fired, embossed mark, or shall be of a type, which once applied cannot be removed withoutbeing destroyed.
3.3.9.1.1 Identification of multipane assemblies.
Multipane assemblies having individual panes not exceeding 0.10m2 in exposed area shall haveat least one pane in the assembly identified. All other panes in the assembly shall be labelled.
3.3.9.2 Louvered windows or jalousies.
Regular, float, wired or patterned glass in jalousies and louvered windows shall be no thinner thannominal 4.80mm and no longer than 1.20m. Exposed glass edges shall be smooth.
3.3.9.2.1 Wired glass prohibited.
Wired glass with wire exposed on longitudinal edges shall not be used in jalousies or louveredwindows.
3.3.9.3 Human impact loads.
Individual glazed areas including glass mirrors in hazardous locations such as those indicatedshall pass the test requirements of CPSC 16-CFR, Part 1201.
3.3.9.4 Hazardous locations.
The following shall be considered specific hazardous locations for the purposes of glazing:
1.Glazing in ingress and means of egress doors except jalousies.
2.Glazing in fixed and sliding panels of sliding (patio) door assemblies and panels in doorsincluding walk-in closets.
3.Glazing in storm doors.
4.Glazing in all unframed swinging doors.
5.Glazing in doors and enclosures for hot tubs, whirlpools, saunas, steam rooms, bathtubs andshowers. Glazing in any part of a building wall enclosing these compartments where the bottomexposed edge of the glazing is less than 1.50m measured vertically above any standing or walkingsurface.
6.Glazing, in an individual fixed or operable panel adjacent to a door where the nearest verticaledge is within a 600mm arc of the door in a closed position and whose bottom edge is less than 1.50mabove the floor or walking surface.
7.Glazing in an individual fixed or operable panel, other than those locations described in Items 5and 6 above, that meets all of the following conditions:
7.1 Exposed area of an individual pane greater than 0.80m2.
7.2 Bottom edge less than 450mm above the floor.
7.3 Top edge greater than 900mm above the floor.
7.4 One or more walking surfaces within 900mm horizontally of the glazing.
8. All glazing in railings regardless of an area or height above a walking surface. Included arestructural baluster panels and non-structural in-fill panels.
9. Glazing in walls and fences enclosing indoor and outdoor swimming pools where the bottomedge of the poolside is (1) less than 1.50m above a walking surface and (2) within 1.50m horizontallyof the water’s edge. This shall apply to single glazing and all panes in multiple glazing.
3.3.9.5 Wind and dead loads on glass.
3.3.9.5.1 Vertical glass.
All glass sloped 15 degrees or less from vertical in windows, window walls, doors and otherexterior applications shall be designed to resist the wind loads specified in Clause 2.3 Design criteriaTable 1 Design pressure for winds. Glazing designed in accordance with these provisions shall befirmly supported on all four edges.
3.3.9.5.2 Sloped glazing.
All glass sloped more than 15 degrees from vertical in skylights, sunspaces, sloped roofs andother exterior applications shall be designed to resist the most critical combinations of loads.
3.3.9.5.3 Thicker glass.
Allowable loads for glass thicker than 6.4 mm shall be determined in accordance with ASTM E1300.
3.3.9.6 Skylights and sloped glazing.
3.3.9.6.1 Definition.
Any installation of glass or other transparent or translucent glazing material installed at a slope of15 degrees or more from vertical. Glazing materials in skylights, solariums, sunspaces, roofs andsloped walls are included in this definition.
3.3.9.6.2 Permitted materials.
The following types of glazing may be used:
1. Laminated glass with a minimum 0.40mm poly-vinyl-butyral interlayer for glass panes 1.50m2 orless in area located such that the highest point of the glass is not more than 3.60m above a walkingsurface or other accessible area; for higher or larger sizes, the minimum interlayer thickness shall be0.80mm.
2. Fully tempered glass.
3. Heat-strengthened glass.
4. Wired glass.
5. Approved rigid plastics.
3.3.9.6.3 Screens general.
For fully tempered or heat-strengthened glass, a retaining screen shall be installed below theglass, except for fully tempered glass.
3.3.9.6.4 Screens with multiple glazing.
When the inboard pane is fully tempered, heat-strengthened, or wired glass, a retaining screenshall be installed below the glass.
3.3.9.6.5 Screens not required.
Screens shall not be required when fully tempered glass is used as single glazing or the bottompane in multiple glazing and either of the following conditions is met:
1. Glass area 1.50m2 or less. Highest point of glass not more than 3.60m above a walking surfaceor other accessible area, nominal glass thickness not more than 4.80mm, and (for multiple glazingonly) the other pane or panes fully tempered, laminated or wired glass.
2. Glass area greater than 1.50m2. Glass sloped 30 degrees or less from vertical and highest pointof glass not more than 3.00m above a walking surface or other accessible area.
3.3.9.6.6 Screen characteristics.
The screen and its fastenings shall
1 - be capable of supporting twice the weight of the glazing.
2 - be firmly and substantially fastened to the framing members, and
3 - have a mesh opening of no more than 25 mm by 25 mm.
3.3.9.6.7 Curbs for skylights.
All unit skylights installed in a roof with a pitch flatter than 25 percent slope shall be mounted on acurb extending at least 100mm above the plane of the roof unless otherwise specified in themanufacturer’s installation instructions.
3.3.10 Enclosed garages
3.3.10.1 Opening protection.
Openings from a private garage directly into a room used for sleeping purposes shall not bepermitted.
Other openings between the garage and residence shall be equipped with either solid wood doorsnot less than 35 mm in thickness or 20-minute fire-rated doors.
3.3.10.1.1 Duct penetration.
Ducts penetrating and installed in the walls or ceilings separating the dwelling from the garageshall be constructed of a minimum 0.50mm sheet steel and shall have no openings into the garage.
3.3.10.2 Separation required.
Enclosed garage shall be separated from the residence with ½ hr fire rated wall and/or slab.
3.3.10.3 Floor surface.
Garage and carport floor surfaces shall be of approved non-combustible material.
The area of floor used for parking of automobiles or other vehicles shall be sloped to facilitate themovement of liquids to a drain or toward the main vehicle entry doorway.
Exception:
Asphalt surfaces shall be permitted at ground level in carports only.
3.3.11 Emergency escape and rescue openings
3.3.11.1 Emergency escape and rescue required.
Basements with habitable space and every sleeping room shall have at least one openableemergency escape and rescue window or exterior door opening for emergency escape and rescue.
Where openings are provided as a means of escape and rescue they shall have a sill height of notmore 1.10m above the floor. The net clear opening dimensions required by this section shall beobtained by the normal operation of the window or door opening from the inside. Escape and rescue
window openings with a finished sill height below the adjacent ground elevation shall be provided witha window well.
3.3.11.1.1 Minimum opening area.
All emergency escape and rescue openings shall have a minimum net clear opening of 0.50m2.
3.3.11.1.2 Minimum opening height.
The minimum net clear opening height shall be 600mm.
3.3.11.1.3 Minimum opening width.
The minimum net clear opening width shall be 600mm.
3.3.11.2 Window wells.
The horizontal dimensions of a window well shall allow the emergency escape and rescueopening to be fully opened. The horizontal dimensions of the window well shall provide a minimum netclear area of 0.85m2 with a minimum horizontal projection and width of 900 mm.
3.3.11.2.1 Ladder and steps.
Window wells with a vertical depth greater than 1.10m below the adjacent ground level shall beequipped with a permanently affixed ladder or steps usable with the window in the fully open position.
Ladders or rungs shall have an inside width of at least 300mm, shall project at least 75mm fromthe wall and shall be spaced not more than 450mm on centre vertically for the full height of the windowwell.
3.3.11.3 Bars, grills, covers and screens.
Bars, grills, covers, screens or other obstructions placed over emergency escape and rescueopenings or window wells that serve such openings shall be releasable or removable from the insidewithout the use of a key, tool or special knowledge.
3.3.12 Exits
3.3.12.1 Exit door required.
Not less than one exit door conforming to this chapter shall be provided from each dwelling unit.The required exit door shall provide for direct access from the habitable portions of the dwelling to theexterior without requiring travel through a garage or kitchen.
If the distance, measured centre of the corridor, between the house main entrance and the insidekitchen door is more than 6m a second exit is required directly in the kitchen.
3.3.12.2 Type of lock or latch.
All egress doors shall be readily openable from the side from which egress is to be made withoutthe use of a key.
3.3.12.3 Type and Size.
The required exit door shall be a side-hinged door that allow a clear opening not less than 900mmin width and 2025mm in height.
Other exterior hinged or sliding doors shall not be required to comply with these minimumdimensions.
3.3.12.4 Hallways.
The minimum width of a hallway or exit access shall be not less than 1m.
3.3.12.5 Exit facilities.
Exterior exit balconies, stairs and similar exit facilities shall be positively anchored to the primarystructure at not over 2.40m on centre or shall be designed for lateral forces. Such attachment shall notbe accomplished by use of toenails or nails subject to withdrawal.
Fig A3-6 Stairs and landings
900mm min 900mm min 900mm min
1m mini
2m min
2m min
12 highs maximum
Bottom landing
Intermediate landing
Top landing
Floor to floor
900mm
900mm min
1m min
1m min
Minimum clearance
2.15m min
2.15m min
minimum opening in slab
12 highs maximum
900mm min
1m min
900mm
1m min
3.3.13 Landings on stairways
3.3.13.1 Landings required.
There shall be a floor or landing at the top and bottom of each stairway. There shall be a floor orlanding on each side of an exit door.
3.3.13.2 Size.
See Figure A3-6 Stairs and landings
The width of each landing shall not be less than the stairway or door served. Every landing shallhave a minimum dimension of 900mm measured in the direction of travel.
3.3.13.3 Location.
The floor or landing shall be not more than 35mm lower than the top of the threshold.
3.3.13.4 Landing required.
A minimum 1m by 900mm landing shall be provided:
1. At the top and bottom of ramps,
2. Where doors open onto ramps,
3. Where ramps changes direction,
4. After no more than 12 high steps.
3.3.14 Pedestrian ramps
See figure A3-7 Ramps and landings
3.3.14.1 Maximum slope.
Ramps shall have a maximum slope of 10 percent.
3.3.14.2 Handrails required.
Handrails shall be provided on at least one side of all ramps.
3.3.14.3 Landing required.
A minimum 1m by 1m landing shall be provided:
1. At the top and bottom of ramps,
2. Where doors open onto ramps,
3. Where ramps changes direction,
3.3.15 Stairways
3.3.15.1 Width.
Stairways shall not be less than 900mm in clear width at all point.
3.3.15.2 Treads and risers.
The maximum riser height shall be 200mm and the minimum tread depth shall be 250mm. Riseand tread should respect the formula 600mm < 2xRise + Tread < 640mm.
The riser height shall be measured vertically between leading edges of the adjacent treads. Thetread depth shall be measured horizontally between the vertical planes of the foremost projection ofadjacent treads and at a right angle to the tread’s leading edge.
The walking surface of treads and landings of a stairway shall be sloped no steeper than 2 percentslope.
The greatest riser height within any flight of stairs shall not exceed the smallest by more than 5mm. The greatest tread depth within any flight of stairs shall not exceed the smallest by more than10mm.
The treads finishing should not be slippery.
Fig A3-7 Ramps and landings
1m minimum
Maximum slope 10%
1m minimum
1m minimum
1m minimum
1m minimum
1m minimum
1m minimum
1m minimum
1m minimum
1m minimum
1m minimum
Bottom landing
Top landing
Intermediate landing
Intermediate landing
Top landing
Up
Up
Up
Up
Up
Top landing
Top landing
Bottom landing
Bottom landing
Bottom landing
1m minimum
Fig A 3-8 Steps (Treads, risers and nosing)
tread depth 250mm min
riser height 200mm max
100mm max
250mm min
200mm maximum
30° max
R 10mm maximum
30° max
R 10mm max
Min 20mm / Max 32mm
Nosing
Open risers
Sloped risers
Fig A 3-9 Stair handrails
1m (+/- 10mm)
Handrail
1m minimum
900mm minimum
40mm minimum32mm min/ 65mm max
900mm minimum
32mm min / 65mm max40mm minimum 40mm minimum
Two handrails
One handrail
R mini = 5mm2m min
F
Section F
3.3.15.2.1 Profile.
The radius of curvature at the leading edge of the tread shall be no greater than 10mm.
See figure A3-8 Steps (Treads, risers and nosing)
When nosing is provided, shall be not less that 20mm but not more than 32 mm on stairways withsolid risers. Bevelling of nosing shall not exceed 10mm.
Risers shall be vertical or sloped from the underside of the leading edge of the tread above at anangle not more than 30 degrees from the vertical. Open risers are permitted, provided that theopening between treads does not permit the passage of a 100mm sphere.
3.3.15.3 Headroom.
The minimum headroom in all parts of the stairway shall not be less than 2.00m measuredvertically from the sloped plane adjoining the tread nosing or from the floor surface of the landing orplatform.
See figures A3-6 and A3-9.
3.3.15.4 Winders.
Winders are permitted, provided that the depth of the tread at a point not more than 500mm fromthe side where the treads are narrower should be not less than the depth of tread of the other section.
The continuous handrail required shall be located on the side where the tread is narrower.
3.3.15.5 Spiral stairs.
Spiral stairways are permitted, provided the minimum width shall be 700mm with each treadhaving a 200mm minimum tread depth at 350mm from the narrow edge. All treads shall be identical,and the rise shall be no more than 240mm. Minimum headroom of 2.00m shall be provided.
3.3.15.6 Circular stairways.
Circular stairways shall have a tread depth at a point not more than 350mm from the side wherethe treads are narrower of not less than 300mm and the minimum depth of any tread shall not be lessthan 150mm. Tread depth at any walking line, measured a consistent distance from a side of thestairway, shall be uniform.
3.3.15.7 Wooden stair protection.
Any enclosed accessible space under stairs shall have walls, under stair surface and any soffitsprotected on the enclosed side with 13mm gypsum board.
Note: All stairs shall be provided with illumination in accordance with Electrical Code.
3.3.16 Handrails
3.3.16.1 Handrails.
Handrails having minimum heights of 1.00m measured vertically from the nosing of the treadsshall be provided on at least one side of stairways. All required handrails shall be continuous for thefull length of any stairs with three or more risers. Ends shall be returned or shall terminate in newelposts or safety terminals. Handrails adjacent to a wall shall have a space of not less than 40mmbetween the wall and the handrail.
See figures A3-9 Stair handrails and A3-10 Guards.
Fig A3-10 Guards
height more than 750mm
1m minimum
1m (+/- 10mm)
Stair without string
1m (+/- 10mm)
Stair with string
String
Not acceptable
Not acceptable
Ø100mm min
Ø100mm min
Ø100mm min
Ø100mm min
3.3.16.2 Handrail grip size.
The handgrip portion of handrails shall have a cross section of 32mm minimum to 65mmmaximum. Other handrail shapes, which provide an equivalent grasping surface, are permissible.Edges shall have a minimum radius of 3mm.
3.3.17 Guards
3.3.17.1 Guards required.
Porches, balconies or raised floor surfaces located more than 750mm above the floor or gradebelow shall have guards not less than 1.00m in height. Open sides of stairs with a total rise of morethan 750mm above the floor or grade below shall have guards not less than 1.00m in height measuredvertically from the nosing of the treads.
See Figure A3-10 Guards
3.3.17.2 Guard rail-opening limitations.
Required guards on open sides of stairways, raised floor areas, balconies and porches shall haveintermediate rails or ornamental closures which do not allow passage of a sphere 100mm or more indiameter. Required guards shall not be constructed with horizontal rails or other ornamental patternthat results in a ladder effect.
3.3.18 Foam plastic
3.3.18.1 General.
The provisions of this section shall state the requirements and uses of foam plastic as insulation,structural filling or decoration
3.3.18.2 Foam characteristics
3.3.18.2.1 Internal characteristics
The minimum density shall be more than 3 kN/m3.
3.3.18.2.2 Surface burning characteristics.
All foam plastic or foam plastic cores in manufactured assemblies used in building constructionshall have a flame-spread rating of not more than 75 and shall have a smoke-developed rating of notmore than 450 when tested for the maximum thickness intended for use in accordance with ASTM E84.
3.3.18.3 Foam protection
All foam shall be protected from inside and outside by appropriated barrier to prevent damagefrom.
1- Vapour (humidity from hot air migrating from the hot side to the cold side of the wall, in thisregion from outside to inside)
2- Fire (both sides)
3- Rodent (rats, mice, etc.)
4- Termites
3.3.18.3.1 Thermal barrier
Foam plastic shall be separated from the exterior of the building by minimum vapour barrier asfollows:
Polythene 0.150 mm thick (included in the wall complex)
or metallic cladding (corrosion resistant sheet of 0.50 mm minimum)
or 25mm thickness of masonry or concrete
3.3.18.3.2 Fire barrier
To allow a minimal ignition protection of 15minutes a fire barrier shall be used as follows:
3.3.18.3.2.1 From outside
Metallic cladding (corrosion resistant sheet of 0.50 mm minimum)
or 25mm thickness of masonry or concrete
or 20mm structural woodor 25mm particleboard.
3.3.18.3.2.2 From inside
Metallic cladding
or 25mm thickness of masonry or concrete
or 20mm structural wood
or 25mm particle boardor 13mm gypsum board (the gypsum board shall be installed using a mechanical fastening
system to ensure that the gypsum board will remain in place when exposed to fire).
3.3.18.3.3 Rodent damage (rats, mice, etc.)
All foam shall be externally protected against any destruction by rodents. This applies to the edgeof the foam.
3.3.18.3.4 Termite damage.
The use of foam plastics in areas of termite infestation shall be in accordance with this code.
3.3.18.4 Specific requirements.
3.3.18.4.1 Foam-filled doors.
Foam-filled doors are exempt from the requirements of this Section.
3.3.18.4.2 Interior trim.
Foam plastic trim defined as picture moulds, chair rails, baseboards, handrails, ceiling beams,door trim and window trim may be installed, provided that:
1. The minimum density is 3.50kN/m3,
2. The maximum thickness of the trim is 13mm and the maximum width is 100mm, The trimconstitutes no more than 10 percent of the area of any wall or ceiling, and
The flame-spread rating does not exceed 75 when tested per ASTM E 84. The smoke-developedrating is not limited.
3.3.19 Flame spread and smoke density
3.3.19.1 Wall and ceiling.
Wall and ceiling finishes shall have a flame-spread classification of not greater than 200.
3.3.19.2 Smoke developed index.
Wall and ceiling finishes shall have a smoke developed index of not greater than 450.
3.3.19.3 Testing.
Tests shall be made in accordance with ASTM E 84.
3.3.20 Insulation
3.3.20.1 Insulation.
Insulation materials, including facings, such as vapour barriers or breather papers installed withinfloor-ceiling assemblies, roof-ceiling assemblies, wall assemblies, crawl spaces and attics shall have aflame-spread index not to exceed 25 with an accompanying smoke developed index not to exceed450 when tested in accordance with ASTM E 84.
3.3.20.2 Loose-fill insulation.
Loose-fill insulation materials, which cannot be, mounted in the ASTM E 84 apparatus without ascreen or artificial supports shall have a flame-spread rating not to exceed 25 with an accompanyingsmoke-developed factor not to exceed 450 when tested in accordance with CAN/ULC-SI02-M88.
3.3.20.3 Cellulose loose-fill insulation.
Cellulose loose-fill insulation shall comply with CPSC 16-CFR, Parts 1209 and 1404. Eachpackage of such insulating material shall be clearly labelled in accordance with CPSC 16-CFR, Parts1209 and 1404.
3.3.20.4 Exposed attic insulation.
All exposed insulation materials installed on attic floors shall have a critical radiant flux not lessthan 1200 watt/m2.
3.3.20.5 Testing.
Tests for critical radiant flux shall be made in accordance with ASTM E 970.
3.3.21 Dwelling unit separation
3.3.21.1 Multi-family dwellings.
Dwelling units in multi-family dwellings shall be separated from each other by wall and/or floorassemblies of not less than 1 hour fire-resistive rating when tested in accordance with ASTM E 119.
Fire-resistive-rated floor-ceiling and wall assemblies shall extend to and be tight against theexterior wall, and wall assemblies shall extend to the underside of the roof sheathing.
3.3.21.1.1 Supporting construction.
When floor assemblies are required to be fire-resistive, the supporting construction of suchassemblies shall have an equal or greater fire-resistive rating.
3.3.21.2 Townhouses.
Each townhouse shall be considered a separate building and separated by walls for exteriorwalls.
A common 2-hour fire resistive wall is permitted for townhouses if such walls do not containplumbing or mechanical equipment, ducts or vents in the cavity of the common wall.
Electrical installations shall be installed in accordance with TTS 26 20 505 Electrical code.
Penetrations of electrical outlet boxes shall be in accordance with this code.
3.3.21.2.1 Continuity.
The common wall for townhouses shall be continuous from the foundation to the underside of theroof sheathing, deck or slab and shall extend the full length of the common wall.
3.3.21.2.2 Parapets.
Where parapets are to be provided for townhouses as an extension of the common wall inaccordance with the following:
Where roof surfaces adjacent to the wall are at the same elevation, the parapet shall extend notless than 800mm above the roof surfaces.
Where roof surfaces adjacent to the wall are at different elevations and the higher roof is not morethan 800 mm above the lower roof, the parapet shall extend not less than 800mm above the lower roofsurface.
3.3.21.2.3 Structural independence.
Each individual townhouse shall be structurally independent.
3.3.21.3 Exceptions:
Foundations supporting common walls.
Structural roof and wall covering sheathing from each unit may fasten to the common wallframing.
Non structural wall coverings.
Flashing at termination of roof covering over common wall.
Townhouses separated by a common two-hour fire-resistive wall.
3.3.21.4 Sound transmission.
Wall and floor-ceiling assemblies separating dwelling units shall provide airborne sound insulationfor walls and both airborne and impact sound insulation for floor-ceiling assemblies.
3.3.21.4.1 Airborne sound.
Airborne sound insulation for wall and floor-ceiling assemblies shall meet a Sound TransmissionClass (STC) of 45 when tested in accordance with ASTM E 90.
3.3.21.4.2 Structural-borne sound.
Floor/ceiling assemblies between dwelling units or between a dwelling unit and a public or servicearea within a structure shall have an impact insulation class ( IIC ) rating of not less than 45 whentested in accordance with ASTM E492.
3.3.21.5 Rated penetrations.
Penetrations of wall or floor/ceiling assemblies are required to be fire resistant or should beprotected in accordance with this section.
3.3.21.5.1 Through penetrations.
Through penetrations of fire resistance rated wall or floor assemblies shall comply with thissection.
Exception: Where the penetrating items are steel, ferrous or copper pipes or steel conduits, theannular space shall be permitted to be protected as follows:
1 In concrete or masonry wall or floor assemblies where the penetrating items is a maximum of150mm nominal diameter and the opening is a maximum of 90 000mm2, concrete, grout or mortarshall be permitted where installed in the full thickness of the wall or floor assemblies.
2 The material used to fill the annular space shall prevent the passage of flame and hot gases atthe location of the penetration for the time period equivalent to the fire resistance rating of theconstruction.
3.3.21.5.1.1 Fire resistance rated assembly.
Penetrations shall be installed as tested in the approved fire resistance rated assembly.
3.3.21.5.1.2 Penetration fire-stop system.
Penetrations shall be protected by an approved penetration fire-stop system installed as tested inaccordance with ASTM E814, with a minimum positive pressure differential of 0.25mm of water (3 Pa)and shall have an F rating of not less than the required fire resistance rating of the wall or floor /ceilingassembly penetrated.
3.3.21.5.2 Membrane penetrations.
Where walls are required to have a minimum 1hour fire-resistance rating, recessed light fixturesshall be so installed such that the required fire resistance will not be reduced.
3.3.21.6 Non-rated penetrations.
Penetrations of horizontal assemblies without a required fire resistance rating shall comply withthis section.
3.3.21.6.1 Non combustible penetrating items.
Non combustible penetrating items that connect not more than three stories are permittedprovided that the annular space is filled with an approved non-combustible material or approvedpenetration fire-stop system.
3.3.21.6.2 Combustible penetrating items.
Combustible penetrating items that connect not more than two stories are permitted provided thatthe annular space is filled with an approved material to resist the free passage of flame and theproducts of combustion.
3.3.22 Moisture vapour retarders
3.3.22.1 Moisture control.
In all framed walls, floors and roof/ceilings comprising elements of the building thermal envelope,an approved vapour retarder having a maximum rating of 1.0 perm, when tested in accordance withASTM E96-92, (Standard Test Methods for Water Vapour Transmission of Materials), shall beinstalled on the warm side of the insulation.
3.3.23 Protection against decay
3.3.23.1 Location required.
In areas subject to decay damage the following locations shall require the use of an approvedspecies and grade of lumber, pressure preservatively treated, or decay-resistant.
See Table C1 Timber names for use in Trinidad & Tobago.
Wood joists or the bottom of a wood structural floor when closer than 450mm or wood girderswhen closer than 300mm to exposed ground in crawl spaces or un-excavated area located within theperiphery of the building foundation.
All sills or plates, which rest on concrete or masonry exterior walls and are less than 200mm fromexposed ground.
Sills and sleepers on a concrete or masonry slab, which is in direct contact with the ground unless,separated from such slab by an impervious moisture barrier.
The ends of wood girders entering exterior masonry or concrete walls having clearances of lessthan 15mm on tops, sides and ends.
Wood siding, sheathing and wall framing on the exterior of a building have a clearance of less than150mm from the ground.
Wood structural members supporting moisture-permeable floors or roofs which are exposed to theweather, such as concrete or masonry slabs, unless separated from such floors or roofs by animpervious moisture barrier.
Wood furring strips or other wood framing members attached directly to the interior of exteriormasonry walls or concrete walls below grade except where an approved vapour retarder is appliedbetween the wall and the furring strips or framing members.
Table C1 Timber names for use in Trinidad & Tobago (first part)
Furniture FlooringExternaljoinery
Internaljoinery
StructureRoofingshingle
Decay Termites
Local woodsAngelia 0.80 xBalata 1.05 x x x beefwood
Bamboo scaffoldingBois gris 0.95 x X resist to "Capricorn"
Boya mulatre or bois mulatre 0.80 fineleafCajuca 0.48
Caribbean pine 0.80Cedar 0.50 x x
Crabwood or Crappo 0.70 x x x xDeterma 0.62 - x x X Laurier
Fiddlewood (black) 0.80Fiddlewood (white) 0.72
Galba or Santa Maria 0.64Gommier 0.56
Guatecare 1.04Gumbo limbo see Gommier
Hog plum 0.48Lay layMahoe 0.56
Mahoe or sterculia 0.60 x x maho cochonMahogany
Mangrue (yellow) or Manni 0.70 x x x x x xMilkwood 0.56
Mora or Muru 0.96 x xNargusta or white oliver 0.80 x x x x
Olivier mangue or Poirier 0.80Pink poui or apamate 0.56
Podocarp or Wild pine 0.56Poui (black) 1.12Purple heart 0.88
Redwood XResclu or Water wood x
Saman 0.56Sandbox 0.45 x must be treatedSardine 0.80
Silk cotton tree 0.38 packagingSimarouba 0.45 x x acajou blanc
Snakewood or Galia 1.15 art craftTabebuia white or Calabash x
Tapana 0.80Tapanare or Suradam 0.70 x x X
Teak 0.65 x x x x xTonka 1.08 x x x art craft
Yellow poui or Bethabara 1.12 x x x green heart?
Recommended useComments
Resistant toT n T local name
Normaldensityat 12%
Table C1 Timber names for use in Trinidad & Tobago (second part)
Furniture Flooring Externaljoinery
Internaljoinery
Structure Roofingshingle
Decay Termites
Imported woods
TropicalAn gelique 0.80 x x x x x X basralocust
Babeon 0.47 xBagasse 0.82 x x x x x XCajuca 0.48
Eastern red cedar XGommier x
Green heart 1.04 x XGronfoeloe 0.70 x x x
Kopie 0.82 x x x x bois cacaLocust or Courbarli 0.85 x x x x locust
Manbarklak 1.02 x XPakuri 0.83 x x x x
Wacapou 0.90 x x X brown heartWallaba 0.85 x xWamara 1.20 x iron wood
0.58 x x x x0.50 x bois lait or bois vache0.85 x x
Non tropicalDouglas fir 0.61 x x x x from W Canada & USAPitchpine 0.52 x x
References
TTS 16 40 000:1978 1978USDA web site 2000
Magazine 2000Les bois de Guyane 1990Construire en bois de Guyane 1990Prinicipaux bois indigènes etexotiques 1975
Resistant toComments
Normaldensityat 12%
Recommended useT n T local name
3.3.23.1.1 Ground contact.
All wood in contact with the ground and which supports permanent structures intended for humanoccupancy shall be approved pressure preservatively treated wood suitable for ground contact use.
3.3.23.1.2 Geographical areas.
In geographical areas where experience has demonstrated a specific need, approved naturallydurable or pressure preservatively treated wood shall be used for those portions of wood memberswhich form the structural supports of buildings, balconies, porches, or similar permanent buildingappurtenances when such members are exposed to the weather without adequate protection from aroof, eaves, overhang or other covering which would prevent moisture or water accumulation on thesurface or at joints between members.
Such members may include:
Horizontal members such as girders, joists and decking.
Vertical members such as posts, poles and columns.
Both horizontal and vertical members.
3.3.23.1.3 Post, poles and columns.
Posts, poles, and columns supporting permanent structures which are embedded in concrete indirect contact with the ground or embedded in concrete exposed to the weather shall he approvedpressure preservatively treated wood suitable for ground contact use.
3.3.23.1.4 Wood columns.
Wood columns shall be approved woods of natural decay resistance or approved pressurepreservatively treated wood.
Posts or columns must be supported by piers or metal pedestals projecting 50mm minimum abovethe floor or finish grade and are separated therefrom by an approved impervious moisture barrier.
3.3.23.2 Quality mark.
Lumber and plywood required to be pressure preservatively treated shall bear the quality mark ofan approved inspection agency which maintains continuing supervision, testing and inspection overthe quality of the product.
3.3.23.2.1 Required information.
The required quality mark on each piece of pressure preservatively treated lumber or plywoodshall contain the following information:
Identification of the treating plant.
Type of preservative.
The minimum preservative retention.
End use for which product was treated.
Standard to which product was treated.
Identity of the approved inspection agency.
The designation “Dry,” if applicable.
3.3.23.3 Exception:
Quality marks on lumber less than 25 mm nominal thickness, or lumber less than nominal 25mmby 125mm or 50mm by 100mm or lumber 900mm or less in length shall be applied by stamping thefaces of exterior pieces or by end labelling not less than 25 percent of the pieces of a bundled unit.
3.3.23.4 Fasteners.
Fasteners for pressure preservative and fire-retardant-treated wood shall be of hot-dippedgalvanised steel, stainless steel, silicon bronzes or copper.
3.3.24 Protection against termites
3.3.24.1 Subterranean termite control.
In areas susceptible to termite damage, methods of protection shall be by chemical soil treatment;pressure preservatively treated wood in accordance with the AWPA standards, naturally termite-resistant wood or physical barriers (such as metal or plastic termite shields), or any combination ofthese methods.
3.3.24.2 Chemical soil treatment.
The concentration, rate of application and treatment method of the termiticide shall be consistentwith and never less than the termiticide label.
3.3.24.3 Pressure preservatively treated and naturally resistant wood.
See Table C1 Timber names for use in Trinidad & Tobago for the list of naturally termiteresistant wood.
Pressure preservatively treated wood and naturally termite-resistant wood shall not be used as aphysical barrier unless a barrier can be inspected for any termite shelter tubes around the inside andoutside edges and joints of a barrier.
3.3.24.3.1 Field treatment.
Field cut ends, notches and drilled holes of pressure preservatively treated wood shall beretreated in the field.
3.3.25 Site address
3.3.25.1 Premises identification.
Approved numbers or addresses shall be provided for all new buildings in such a position as to beplainly visible and legible from the street or road fronting the property.
3.3.26 Flood resistant construction
3.3.26.1 General.
All buildings and structures erected in areas prone to flooding and classified as either flood hazardareas or coastal high hazard areas shall be constructed and elevated as required by the provisionscontained in this section.
3.3.26.1.1 Structural systems.
All structural systems of all buildings and structures shall be designed, connected and anchoredto resist flotation, collapse or permanent lateral movement due to structural loads and stresses fromflooding equal to the design flood elevation.
3.3.26.1.2 Flood resistant construction.
All buildings and structures erected in flood hazard zones shall be constructed by methods andpractices that minimise flood damage.
3.3.26.1.3 Establishing the design flood elevation.
The design flood elevation shall be used to define areas prone to flooding, and shall describe, at aminimum, the base flood elevation at the depth or peak elevation of flooding (including wave height)which has a 1-percent (100-year flood) or greater chance of being equated or exceeded in any givenyear. This level should be determined by the physical planning standards
3.3.26.1.4 Lowest floor.
The lowest floor shall be the floor of the lowest enclosed area, including basement, but excludingany unfurnished flood-resistant enclosure that is useable solely for vehicle parking, building access, orlimited storage provided that such enclosure is not built so as to render the building or structure inviolation of this Section.
3.3.26.1.5 Protection of mechanical and electrical systems.
New and replacement electrical equipment, ventilating, air conditioning plumbing connections,and other service equipment shall be located at or above the design flood elevation.
Electrical wiring and outlets, switches, junction boxes and panels shall be elevated to or above thedesign flood elevation for location of such items in wet locations.
Ducts and duct installation shall not be installed below the design flood elevation.
3.3.26.1.6 Protection of water supply and sanitary sewage systems.
New and replacement water supply systems shall be designed to minimise infiltration of floodwaters into the systems in accordance with the plumbing provisions of this code.
New and replacement sanitary sewage systems shall be designed to minimise infiltration offloodwaters into systems and discharges from systems into floodwaters.
3.3.26.1.7 Flood resistant materials.
Building materials used below the design flood elevation shall comply with the following:
All wood, including floor sheathing shall be pressure preservatively treated, or decay-resistant forthe list of foreign and local woods See Table C1 Timber names for use in Trinidad & Tobago
3.3.26.1.8 As-built elevation certifications.
A licensed land surveyor or registered designed professional shall certify that the building orstructure is in compliance with the elevation required.
3.3.26.2 Flood hazard areas.
All areas, which have been determined to be prone to flooding but not subject to high velocitywave action shall be designated as flood hazard areas.
3.3.26.2.1 Elevation requirements.
Buildings and structures shall have lowest floors elevated to or above the design flood elevation;
In areas of shallow flooding, buildings and structures shall have the lowest floor (includingbasement) elevated at least as high above the highs natural adjacent grade as the depth numberspecified in metre, or at least 600mm if a depth number is not specified;
Basement floors that are below grade on all sides shall be elevated to or above the design floodelevation.
3.3.26.2.2 Enclosed area below design flood elevation.
Enclosed areas, including crawl spaces, that are below the design flood elevation shall;
Be used solely for parking of vehicles, building access, or storage; and
Be provided with flood openings, which shall meet the following criteria;
a. There shall be a minimum of two openings on different sides of each enclosed area; if a buildinghas more than one enclosed area below the design flood elevation, each area shall have openings onexterior walls.
b. The total net area of all openings shall be at least 1/150 of enclosed area.
c. The bottom of each opening shall be 300mm or less above the adjacent ground level.
d. Openings shall be at least 75mm in diameter.
e. Any louvers, screens or other opening covers shall allow the automatic flow of floodwaters intoand out of the enclosed area.
f. Openings installed in doors and windows, which meet requirement (a) through (e), areacceptable; however, doors and windows without installed openings do not meet the requirement ofthis section.
3.3.27 Coastal high hazard areas.
Areas, which have been determined to be subject to wave heights in excess of 900mm or subjectto high velocity wave action or wave induced erosion, shall be designated as coastal high hazardareas.
All buildings and structures erected in coastal high hazard areas shall be designated andconstructed in accordance with this Sections
3.3.27.1 Elevation requirements.
1. All buildings and structures erected within coastal high hazard areas shall be elevated so thatthe lowest portion of all structural members supporting the lowest floor, with the exception of mat orraft foundations, piling, pile caps, columns, grade beams and bracing, is located at or above the designflood elevation.
2. Basement floors that are below grade on all sides are prohibited.
3. The use of fill for structural support is prohibited,
4. The placement of fill beneath buildings and structures is prohibited.
3.3.27.2 Foundations.
All buildings and structures erected in coastal high hazard areas shall be supported on pilings orcolumns and shall be adequately anchored to such pilings or columns. Piling shall have adequate soilpenetrations to resist the combined wave and wind loads (lateral and uplift). Water loading valuesused shall be those associated with the design flood. Wind loading values shall be those required bythis code. Pile embedment shall include consideration of decreased resistance capacity caused byscour of soil strata surrounding the piling.
Mat, raft, or other foundations, which support columns, shall not be permitted where soilinvestigations that indicate that soil material under the mat, raft, or other foundation is subject to scouror erosion from wave-velocity flow conditions.
3.3.27.3 Walls below design flood elevation.
Walls and partitions are permitted below the elevated floor, provided that such walls and partitionsare not part of the structural support of the building or structure and;
1. Are constructed with insect screening or open lattice; or
2. Designed to break away or collapse without causing collapse, displacement or other structuraldamage to the elevated portion of the building or supporting foundation system.
Such walls, framing, and connections shall have a design safe loading resistance of not less than0.50 kN/m2 and no more than 1.00 kN/m2; or
3. Where wind loading values of this code exceed 1.00 kN/m2, a registered design professionalshall certify the following:
A. Collapse of walls and partitions below the design flood elevation shall result from a water loadless than that which would occur during the design flood; and
B. The elevated portion of the building and supporting foundation system shall not be subject tocollapse, displacement, or other structural damage due to the effects of wind and flood loads actingsimultaneously on all building components (structural and non-structural). Water loading values usedshall be those associated with the design flood. Wind loading values used shall be those required bythis code.
3.3.27.4 Enclosed areas below design flood elevation.
Enclosed areas below the design flood elevation shall be used solely for parking of vehicles,building access, or Storage.
3.4 Basic materials
3.4.1 Reinforced Concrete
3.4.1.1 Materials
Concrete shall be manufactured from ordinary Portland cement, sand, gravel and water.
3.4.1.1.1
The cement shall be fresh and contained in unopened bags, which have been well protected frommoisture and stored above the ground.
3.4.1.1.2
The sand shall be clean (i.e. free of clayey lumps, organic materials and broken shells), naturalsharp sand, preferably taken from an inland source. Beach sand shall not be used.
3.4.1.1.3
The coarse aggregate shall be of crushed stone or gravel with a size between 15 and 25mm. Theaggregate shall be free of dust coating. In areas where only broken stone is available, care shall betaken to use stone as near to 20 mm as practicable.
3.4.1.1.4
Only clean fresh water shall be used for the mixing of concrete.
3.4.1.2 Mixing
3.4.1.2.1
A concrete mix producing concrete with a minimum compressive cube strength of 21 N/mm2 at 28days or 16.8 N/mm2 at 7 days shall be used. The approximate proportions normally required toproduce such a mix are 42 kg (1 bag) of cement, 0.056 m3 (1 wheelbarrow) of sand, and 0.084 m3 (1½wheelbarrow) of aggregates and approximately 18 l of water.
NOTE: any moisture affects the maximum amount of water required, which may be present in theaggregate. The quality is therefore reduced when the aggregate is wet.
3.4.1.2.2
The cement shall be added by the bag. The fine and coarse aggregates shall be measured incubic metre (m3) and the water shall be measured in litre (l).
3.4.1.2.3
For coastal environment conditions the mix shall be upgraded to 42 kg (1 bag) of cement, 0.056m3 (1 wheelbarrow) of sand, 0.056 m3 (1 wheelbarrow) of aggregate and approximately 15 l of water.
3.4.1.2.4
The concrete shall be mixed by hand or preferably by machine until there are no visible areas ofunmixed materials and a uniform colour is obtained.
Table B-1 Concrete composition
Number ofbag of
Number ofwheelbarrow
of
Number ofwheelbarrow
of
Sand Gravel
Grade "E" 150 4 335 665 nscr nscr 1 - 3 - 6 1 1.5 3
Grade "D" 250 6 400 600 nscr nscr 1 - 2 - 4 1 1 2
Grade "C" 300 7 335 665 23,000 15,000 1 - 2 - 3 1 1 1.5
Grade "B" 350 8 335 665 27,000 18,000 1 - 2 - 2 1 1 1
Grade "A" 400 10 335 665 30,000 20,000 2 - 3 - 4 2 1.5 2
Note :Volume of wheelbarrow 57 litres equivalent 2 in the type of concrete
Type ofconcrete
Cement Sandcontrolledconcrete
concretewithout any
controllitrelitrekg
kN/m2
Trinidad and Tobago
Cement
Proportion for one cubic metre (1 m3)
Metric system
Compression at 28 days
Gravel42 kg bag
3.4.1.3 Form work
3.4.1.3.1
The form work into which the concrete is to be placed shall be strongly constructed of straighttimber so braced that no movement or deformation is caused by the wet concrete under normalconstruction loads.
3.4.1.3.2
The form work shall have close fitting joints so that no fine aggregate, cement or water is lostthrough leakage.
3.4.1.4 Reinforcement
3.4.1.4.1
The minimum requirement for reinforcement steel shall be bars of grade 250 i.e. plain mild steelbars of 250 N/mm2 (minimum yield) stress. This section is based on grade 250 bars; however, highergrades of plain or deformed bars may be used.
3.4.1.4.2 Bar bending
The minimum pin diameter size for steel bar bending in accordance with TTS583: 2000 must beas shown in table B-8
Table B-8 Recommended minimum size bending
Steel gradeBar size " d " In mm
250 420
5 to 16mm 2.5d (12.5 to 40mm) 4d (20 to 64mm)
20 & 25mm Not applicable 5d (100 or 125mm)
32 & 40mm Not applicable 7d (225 or 300mm)
3.4.1.4.3
Reinforcement steel, which shall be free of loose meal scale (rust), shall be properly tied togetherby mild steel tying wire. The whole assembly shall be positioned within the form work withappropriately sized concrete spacers so that the correct concrete cover to the steel is maintained.
3.4.1.4.4
Concrete shall not be vibrated by direct contact between the vibrating instrument and reinforcingbar. The practice of vibrating the form work shall also not be permitted as this may displace the steelfixings. The practice of vibrating the concrete shall therefore be used with caution.
3.4.1.4.5
The recommended concrete covers for normal conditions and coastal environmental conditionsare given in table B-2.
Table B-2 — Recommended concrete cover
Type Concrete Cover in mm
Normalconditions
Coastalenvironmental
conditions
Slabs 25 35
Beams 30 40
Columns 30 40
Surfaces In ContactWith Earth
75 95
NOTEThe recommended concrete cover for coastal environmentalconditions is based on an increase of 25 % for that of normal conditions.
3.4.1.5 Placing Concrete
3.4.1.5.1
Form work shall be thoroughly cleaned to remove sawdust, bits of wood, wire and other debrisbefore placing concrete in it.
3.4.1.5.2
Transporting the concrete over long distances (unless special equipment is used) shall beavoided to prevent segregation of its components.
3.4.1.5.3
All runways and routes between the mixer and the area where the concrete is to be used shouldbe set up beforehand and kept clear, so that the placing of concrete can proceed smoothly withoutinterruptions.
3.4.1.5.4
The poured concrete shall be compacted in the form work by vibration or rodding, so that denseconcrete is obtained. Where necessary, chutes shall be used to place concrete in tight areas such ascolumn forms.
3.4.1.5.5
Where floor slabs or roof slabs cannot be poured in one operation, construction joints shall beused. Professional assistance shall be sought on the proper placing of the construction joints insuspended slabs.
3.4.1.6 Curing
3.4.1.6.1
The optimum concrete strength shall be obtained by proper curing. To achieve this, the pouredconcrete shall be kept moist by wetting with water for two days after it is poured.
3.4.1.6.2
Proprietary curing compounds may be used in accordance with the manufacturer’s instructions.
3.4.1.7 Stripping of form work
The side form work of beams and columns may be removed from the fresh concrete after 24hours. The bottom form work and props for suspended beams and slabs shall remain in place for notless than 10 days.
3.4.2 Timber
3.4.2.1 Type of wood
Walls, floors and roofs can be constructed of approved structural timber.
See Table C1.
3.4.2.2 Preservatively treated lumber
Only treated timber should be used and shall also be identified.
3.4.2.3 Moisture
The timber should be sound, straight and well seasoned timber with moisture content between15% and 20%.
3.4.3 Metal
3.4.3.1 Structural steel
Material conforming to one following standard specifications (latest date of issue) is approved foruse under this code.
- Structural steel, ASTM A36 is the all purpose carbon steel used in building construction
- Welded and seamless steel pipe, ASTM A53, grade B
3.4.3.2 Structural shapes
All shapes are published in the ASTM A6 and the principals used are:
-W shapes have essentially parallel flange surfaces. The profile of a W shape of a givennominal depth and weight.
- HP bearing pile shape have essentially parallel flange surfaces and equal web and flangethickness.
- S beam and C channel have a slope on their flange surfaces.
- L angles shape with equal and unequal leg.
- Pipe and structural tubing.
3.4.3.3 Bolts
Steel bolts shall conform to one of the following standard specification
- Low carbon steel externally and internally threaded standard fasteners, ASTM A307
- High strength bolts for structural steel joints, ASTM A325
- Quenched and tempered steel bolts and nuts, ASTM A449
Fig B-1 Foundation types
Pad footingStrip footing On pile
300mm min
450
Suspended slab
300mm min
600mm
100mm Slab on grade
1000mm min
Crawl space 300mm min
4 Foundations
4.1 General
4.1.1 Load bearing walls and columns
4.1.1.1
All loads bearing walls and columns shall be supported on any of the following reinforced concretefootings:
a) Pad footing
b) Strip footing
c) On pile
The above reinforced concrete footings are shown in figure B-1 Foundations types.
4.1.1.2
Interior walls shall be supported by thickening the slab under the wall and suitably reinforcing it.The foundation should be located on a layer of soil or rock with good bearing characteristics. Suchsoils include dense sands, marl, other granular materials and stiff clays.
4.1.1.3
The foundation shall be cast not less than 600 mm below ground, its thickness not less than 225mm and its width not less than 450 mm or a minimum of three times the width of the wall immediatelysupported by it (see figures B-2-1a and B-2-1b Arrangement of strip footing)
4.1.1.4
When separate reinforced concrete columns or concrete block columns are used they shall besupported preferably by square footings not less than 1000 mm per side and 225 mm thick (see figureB-3 Typical spread footing detail).
4.1.1.5
When the ground is subject to drying (cracks or fissures) the minimum depth above should beincreased under the advice of a professional engineer.
To avoid this increase in depth, the foundation should be protected by surface paving.
4.1.2 Reinforcement
4.1.2.1
For strip footings, the minimum reinforcement shall consist of three 10 mm diameter bars placedlongitudinally and 10 mm diameter bars placed transversely no more than 600 mm between theircentres (see figures B-2-1 and B-2-2).
4.1.2.2
For column footings, the minimum reinforcement shall be 12 mm diameter bars at 150 mmbetween centres in both directions forming a mesh (see figure B-3).
4.1.2.3
Bars may be suitably cranked bent or lapped at the ends. Lapped or cranked lengths shall be aminimum of 40 times the diameter of the bars being joined. Table A-3 gives the minimum lap lengthsfor steel reinforcement.
Table B-3 — Minimum lap lengths for steel reinforcement
Bar diametermm
Minimum lap lengthmm
6 300
10 400
12 600
16 750
Mesh 150 or one square, whichever is greater
Fig B2-1a & 1b Arrangement for strip footing 150mm and 200mm verticalcore blocks
Fig B3 Typical spread footing details
450mm minimum
225
600mm mini
150mm blockworkminimum
r.c. tie beam
150mm blockwork
100mm slab minimum
grade
225
100mm slab minimum
150mm blockwork
600mm min
if 200mm blockwork
3 times 200mm
75
75
75
1000
300
75
grade
225
600mm minimum
75 75mm minimum
75
600mm minimum
12mm rods 150mm crs.
r.c. column
75
30
300 mm
1000 min
Fig B4 1 and 2 level house type
Shear panel
Suspended ground floor slabR.C./ Masonry
with crawl space
R.C./ MasonrySuspended first floor slab
with crawl spaceSuspended ground floor slabMasonry
MasonrySuspended first floor slabGround floor slab suspended
MasonryGround floor slab suspendedor on grade
or on grade
Flat siteSloping site
Fig B5 Load & non load bearing clay or concrete blocks
152
203102
102
290 190
190
390
390
190
190
390
152
190190
390
390
190
152 152or
or
390
190
102
Filled with concrete 152
Load bearing blocks Non load bearing blocks
Clay blocks Clay blocks
Concrete blocks Concrete blocks
Fig 17-1 2 level house - Typical cross section masonry blocks
150mm blockwork
Crawl space 300 mm minimum
150mm blockwork
Minimum slab thickness see table B4
Ring beam 200mm minimum
Ring beam 200mm minimum
Maximum span see table B4
See details figures B14 and/or B 15-1
First floor
Ground level
5 Vertical structures
5.1 Concrete and masonry
5.1.1 Masonry Block Walls
5.1.1.1 General
This section outlines the requirements for structural masonry construction using shear panels forsingle and two storey structures as configured in figure B-4 1or 2 level house type.
5.1.1.2 Workmanship
Cavities shall be clean and substantially free from mortar droppings. Reinforcement shall beplaced centrally and/or properly spaced from the masonry. Reinforcement shall be adequately lappedand secured. The procedure for applying concrete as outlined in clause 3.7.5 shall be adhered to.
5.1.1.3 Hollow Masonry Blocks
5.1.1.3.1
Hollow clay block units shall conform to the latest edition of the ASTM C652-95a Hollow Brick(Hollow Masonry Units Made from Clay or Shale) and/or ASTM C34-96 Structural Clay Load-BearingWall Tile.
Grade 3 clay blocks cannot be considered as structural.
5.1.1.3.2
Load bearing concrete masonry block units shall conform to the latest edition of TTS 16 35 508Specification for Load Bearing Concrete Blocks.
5.1.1.3.3
Non-load bearing interior walls or partitions may be constructed using blocks with a thickness of100 mm or less. Concrete masonry block units for such application shall conform to the latest editionof TTS 16 35 509 Specification for Non-load Bearing Concrete Blocks.
5.1.1.3.4
Figure B-5 shows the various types of load bearing and non-load bearing masonry blocks.
5.1.1.4 Shear Panels
5.1.1.4.1
A shear panel (see figures B-6-1 and B-6-2 Shear panel) is a portion or section of a 150mmexterior wall that performs the function of resisting lateral earthquake or wind forces.
5.1.1.4.2
Where masonry is used there shall be a shear wall on each exterior wall of every house.
5.1.1.4.3
A shear panel should be 1.8 m in horizontal dimension along the face of the wall and a minimumof 150 mm in block and wall thickness extending from floor to ring beam, with no openings orpenetrations. If the shear panel must be divided in two part the total of horizontal dimension increaseto 2.4m with a minimum of 1000mm for the smallest part. (See figures B-6-1 & B-6-2)
Figures B-7-1& B-7-2 shows the various configurations and applications of a shear panel, verticalstiffeners and openings.
Fig B7-1 Typical external wall arrangement - vertical core blocks
horizontal reinforcementevery second course
For ventilation blocks
Alternative for ventilation integrated to the opening
Shear panel
Max 1800mmMax 1800mmMin 400mm
Fig B7-2 Typical external wall arrangement - horizontal core blocks
horizontal reinforcementevery second course
For ventilation blocksShear panel
Max 1800mmMax 1800mmMin 400mm
Shear panel of 1800 mm
5.1.1.5 Block Laying
5.1.1.5.1
Blocks shall be laid in half bond courses which have been aligned using lines and levels (seefigures B-7-1 & B-7-2).
5.1.1.5.2
Walls at junctions and corners shall be bonded to each other by reinforcement and alsointerlocked in half bond. All walls shall be tied to columns or to reinforced corners at every secondcourse.
5.1.1.5.3
Horizontal and vertical mortar joints shall be a minimum thickness of 12 mm and shall be properlyfilled with mortar.
5.1.1.6 Mortar
5.1.1.6.1
Mortar shall be made using, by volume, 1 part of ordinary Portland cement and a maximum of 4parts of clean sifted sand.
5.1.1.6.2
Mortar shall be mixed by hand or preferably by a machine until the ingredients are thoroughlymixed (not less than 3 minutes by machine). A minimum amount of water shall be added to the drymixture to allow for workability. There shall be no re-mixing of mortar.
5.1.1.6.3
Mortar shall be mixed in appropriate amounts so it is completely used within 1 hour.
5.1.1.7 Reinforcement
5.1.1.7.1 Shear panel
See figures B-6-1 and B-6-2 with vertical and horizontal core blocks.
5.1.1.7.1.1 Vertical reinforcement
5.1.1.7.1.1.1 With vertical core blocks
Shear panels shall be vertically reinforced using 12 mm diameter bars placed a distance of 400mm between centres in solid grouted cells. A 1.8 m shear panel would then have five 12 mm diameterbars vertically placed. See figure B-6-1.
5.1.1.7.1.1.2 With horizontal core blocks
Shear panels shall be vertically reinforced using a frame of 2 vertical columns 250mm x 150 mmminimum with 4 x 12 mm diameter bars placed vertically and 6mm diameter bar stirrup each 150 mmin solid concrete. See figure B-6-2.
5.1.1.7.1.2
Vertical reinforcement bars shall be adequately lapped and secured to hook dowels anchored bothin the foundation and the ring beam.
5.1.1.7.1.3
Horizontal reinforcement shall be provided using masonry mesh 50 mm 50 mm 3 mm (2 in 2in 10 G) or an equivalent every two rows. (See figures B-11-1 & B-11-2)
Fig B8 Openings and lintels
2 dia. 12mm bar
2 dia. 12mm bar
2 dia. 12mm bar
2 dia. 10mm bar
2 dia. 12mm bar
2 dia. 12mm bar
Window Door
Ground level
Max 1800mm
Fig B9-1 & 10-1 Typical wall corner & intersection - vertical core blocks
Part plan
Part elevation
Vertical reinforcement
In situ concrete
In situ concrete
Vertical reinforcement
Part plan
Part elevation
Fig B9-2 & 10-2 Typical wall corner & intersection - horizontal core blocks
Part plan
Part elevation
Vertical reinforcement
In situ concrete
In situ concrete
Vertical reinforcement
Part plan
Part elevation
200
mm
min
200 mm min
200
mm
min
250 mm min
Fig B11-1 Typical wall reinforcement and phasing construction
Horizontal core blocks
dia 12mm x 1 000mm
Foundationdia 12mm
Concrete
Phase 0
Concrete
Phase 1 Phase 2
Last Phase
Phase "n"
12
14
13
1
2
1
2
3
4
1
2
3
4
5
6
8
7
40mm2
1
4
3
5
6
Concrete
Phase 3
Horizontal reinforcementevery two course
Acceptable horizontal reinforcement
Fig B11-2 Typical wall reinforcement and phasing construction
Vertical core blocks
Foundationdia 12mm
Phase 0
Phase 1 Block laying and horizontal reinforcement
1
2
Horizontal reinforcementevery two course
Acceptable horizontal reinforcement
1800Horizontal reinforcementevery two course
1800
Vertical stiffener locations
Phase 2 Vertical reinforcement and formwork
Phase 3 Concreting
Form work
1 dia.12mm vertical
1 dia.10mm horizontal
dia 12mm x 1 000mm
Foundationdia 12mm
Concrete
Phase 0
Concrete
Phase 1 Phase 2
Last Phase
Phase "n"
12
14
13
1
2
1
2
3
4
1
2
3
4
5
6
8
7
40mm2
1
4
3
5
6
Concrete
Phase 3
Horizontal reinforcementevery two course
Acceptable horizontal reinforcement
5.1.1.8 Openings
5.1.1.8.1
All openings of 600 mm or greater in any direction shall be reinforced both horizontally andvertically with a minimum of two 10 mm diameter bars. All bars shall extend a distance not less than600 mm beyond each corner of the opening or otherwise anchored by a 300 mm bend inside theconcrete frame (see figure B-8 Openings and lintels).
5.1.1.8.2
Lintels with a span of 600 mm or less shall be horizontally reinforced with two 10 mm diameterbars.
5.1.1.8.3
Lintels with a span ranging from 1.2 m to 1.8 m shall be horizontally and vertically reinforced withtwo 12 mm bars.
5.1.1.8.4
For large openings refer to clause Lintels
5.1.1.9 Load bearing walls (external and internal)
5.1.1.9.1
Masonry walls other than those described above shall be reinforced as follows: -
Three 10 mm diameter bars placed vertically at corners (see figures B-9-1 & B-1-2).
Four 10 mm diameter bars placed vertically at intersections (see figures B-10-1 & B-10-2).
Two 10 mm diameter bars placed vertically at jambs of doors and windows. (See figure B-8)
For vertical wall reinforcement (stiffener) 12 mm diameter bars shall be used spaced 1.8m apart(see figures B-11-1 & B-11-2).
Horizontal reinforcement every two rows (see figures B-11-1 & B-11-2).
5.1.1.10 Non-load bearing walls (internal walls)
The recommended minimum reinforcement for non load bearing walls with concrete blockconstruction (refer to figures B-12-1 & B-12-2) shall be as follows: -
a) One 10 mm diameter bar shall be placed vertically at corners.
b) One 10 mm diameter bar shall be placed vertically at junctions.
c) For vertical wall reinforcement 10 mm bars shall be spaced at a maximum of 2.5 m apart.
5.1.1.11 Concrete in fill
5.1.1.11.1 Vertical core blocks
5.1.1.11.1.1
Load bearing walls shall be filled with 1:2:4 nominal mix (refer to table B 1) into the block cores.The concrete shall be properly compacted, with concrete being added after every two courses of blockerection (see figure B-11-1).
5.1.1.11.1.2
Non-load bearing walls shall be filled with grout or fine aggregate concrete as the work proceeds(see figure B-11-1).
5.1.1.11.1.3
Pouring of concrete into vertical block cores shall be stopped 40 mm below the top of the block inorder to form a key at joints (See figure B-11-1).
5.1.1.11.1.4
The wall reinforcement shall be securely anchored in the wall footing and the ring beam.Horizontal reinforcement shall be embedded in mortar and shall be continuous through intersectionsand corners (see figure B-11-1).
Fig B12-1 Internal wall arrangement and reinforcement - Vertical core
Ring beam
Stifener each 2.50m maximum
Frame Frame
External wall150mm minimum
2.50m maximum 2.50m maximum
Fig B12-2 Internal wall arrangement and reinforcement - Horizontal core
Ring beam
Stifener each 2.50m maximum
Frame Frame
External wall150mm minimum
2.50m maximum 2.50m maximum
Fig B13 Ring beam reinforcement
100mm150mm
100mm
Ring beam - corner reinforcement
4 dia. 12mm bars
300mm
2 x 3 dia 12mm/1m angles
Dia 6mm stirrup details2 x 2 dia 12mm/1m angles
100mm
Ring beam - junction reinforcement
5.1.1.11.2 Horizontal core blocks
5.1.1.11.2.1
Vertical stiffeners and columns integrated in the wall shall be filled with 1:2:4 nominal mix (refer totable B 1) into the form work. The concrete shall be properly poured and compacted after total blockerection in order to insure a good wall interlocking (see figure B-11-2).
5.1.1.11.2.2
The wall reinforcement shall be securely anchored in the wall footing and the ring beam.Horizontal reinforcement shall be embedded in mortar and shall be continuous through intersectionsand corners (see figure B-11-2).
5.1.1.12 Ring beams
5.1.1.12.1
All walls shall be finished at the top by a reinforced concrete ring beam not less than 200 mm indepth.
5.1.1.12.2
The minimum ring beam reinforcement shall be four 12 mm diameter bars with 6 mm diameterstirrups placed 300 mm between centres. The beam width shall be a minimum of 150 mm withoutplaster (see figure B-13).
5.1.1.12.3
The corners of ring beams shall be reinforced as shown in figure B-13.
5.1.1.13 Isolated Columns
Where columns are required for porches, carports etc., construction shall be as follows: -
a) Minimum dimensions shall be 200 mm 200 mm.
b) Columns shall be formed by form work on four sides or form work on two sides with block work onthe other two.
c) Square columns,
The minimum column reinforcement shall be four 12 mm diameter bars with 6 mm diameterstirrups placed 150 mm between centres.
d) Round columns,
Round columns with varying cross-section (fancy columns) shall have a minimum section of200mm diameter and shall be reinforced with six (6) 12mm diameter bars with 6mm diameter roundstirrups placed 150mm between centres.
5.1.1.14 Lintels
5.1.1.14.1
Reinforced concrete lintels shall span all door and window openings and shall extend beyond thejambs by not less than 150 mm.
5.1.1.14.2
The lintel shall be 200 mm deep for openings not greater than 2.5 m in width.
5.1.1.14.3
The reinforcement of the lintel shall be four 12 mm diameter bars and 6 mm diameter stirrupsplaced 200 mm between centres. Reinforcement bars shall be placed in lintels as shown in figure B-8.
5.1.1.15 Chasing
The chasing of walls for the installation of services shall be carefully controlled. Horizontal chasesat any one level shall be restricted to 0.7 m in length and only one side of the wall shall be chased.Chasing shall be done before the walls are plastered and then filled with concrete. No chasing ofstructural members shall be permitted.
5.1.1.16 Services
5.1.1.16.1
Services shall not be carried through shear panels.
5.1.1.16.2
Where services through a structural member other than a shear panel is unavoidable, a sleeve,preferably metallic, shall be provided during the casting operation. The maximum external diameter ofthe sleeve shall be 25 mm. The minimum spacing between sleeves shall be 150 mm.
Fig 17-2 2 level house Typical cross section columns, beams and shearpanel
See details figures B14 and/or B 15-1
Crawl space 300 mm minimum
150mm blockwork see shear panel
Minimum slab thickness see table B4
Ground level
First floor
Section on shear panel
Beam see table B7
5.1.2 Columns, beams and shear panel structure
5.1.2.1 General
This section outlines the requirements for structural columns and beams construction using shearpanels for single and two storey structures as configured in figure A2-1a and A2-1b for 1or 2 levelhouse type.
5.1.2.2 Shear panels
Ditto "Shear panels" in previous paragraph "Masonry block walls" and "Reinforcement".
5.1.2.3 Columns
Columns construction shall be as follows: -
5.1.2.3.1 Sizes
Minimum dimensions shall be 250 mm 250 mm.
5.1.2.3.2 Form work
Columns shall be formed by form-work on four sides or form-work on two sides with block work onthe other two.
5.1.2.3.3 Reinforcement
a) Square columns,
The minimum column reinforcement shall be four 12mm diameter bars with 6mm diameter stirrupsplaced 150 mm between centres.
b) Round columns,
Where round columns are used, or round columns with varying cross-section (fancy columns) shallhave a minimum section of 250mm diameter and shall be reinforced with six (6) 12mm diameter barswith 6mm diameter round stirrups placed 100mm between centres.
5.1.2.3.4 Concrete
Columns shall be filled with 1:1:1 nominal mix (refer to table B 1).
The concrete shall be properly compacted and poured at one time.
5.1.2.4 Beams
Where beams are used, construction shall be as follows:
5.1.2.4.1 Dimensions
Maximum span 5000mm
Minimum section
See table B-7 (1 to 4)
Total height not less than 1/12 span with 300mm minimum. (See table B7)
Table B7-1 Typical reinforcement for concrete beams - 2 ways slab and MSsteel grade 250
Live Load
Width Total height Dia. 1 Number Dia. 2 Number Total Dia. 1 Number Dia. 2 Number Total Dia.
(mm) (mm) (mm) (mm) basic bar (mm) min. mm2 (mm) basic bar (mm) min. mm2 (mm) mini maxiDomestic floor 3.00 250 300 100 12 2 16 2 570 12 2 12 1 317 5 2 50 210 231.50 kN/m2 4.00 250 400 125 12 2 16 4 902 12 2 16 2 501 5 4 50 250 27
5.00 350 450 150 12 2 16 7 1,537 12 2 16 4 854 5 4 50 250 33Office floor 3.00 200 350 100 12 2 16 2 518 12 2 12 1 288 5 2 50 250 202.50 kN/m2 4.00 350 400 125 12 2 16 4 1,016 12 2 16 2 565 5 4 50 250 27
5.00 400 500 150 12 2 16 7 1,540 12 2 16 4 856 5 4 50 250 33Small industrial floor and storage5 kN/m2 2.50 250 300 100 12 2 12 2 465 12 2 10 1 258 5 2 50 220 19
3.50 300 400 125 12 2 16 3 856 12 2 12 3 476 5 4 50 250 23
4.50 400 500 150 12 2 16 6 1,410 12 2 16 3 783 5 4 50 250 30Horizontal span
Roof 3.00 250 300 100 12 2 12 3 542 12 2 10 1 301 5 2 50 220 22
1kN/m2 4.00 300 400 125 12 2 16 3 876 12 2 12 3 264 5 4 50 250 275.00 350 500 150 12 2 16 6 1,326 12 2 16 3 736 5 4 50 250 33
Live Load
Width Total height Dia. 1 Number Dia. Number Total Dia. 1 Number Dia. 2 Number Total Dia.
(mm) (mm) (mm) (mm) basic bar (mm) min. mm2 (mm) basic bar (mm) min. mm2 (mm) mini maxiDomestic floor 3.00 150 350 100 12 2 10 2 374 12 2 208 5 2 50 250 201.50 kN/m2 4.00 200 400 125 12 2 12 4 670 12 2 12 2 372 5 2 50 250 27
5.00 250 500 150 12 2 16 4 976 12 2 16 2 542 5 2 50 250 33Office floor 3.00 150 350 100 12 2 10 2 394 12 2 219 5 2 50 250 202.50 kN/m2 4.00 200 400 125 12 2 12 5 712 12 2 12 2 395 5 2 50 250 27
5.00 250 500 150 12 2 16 4 1,039 12 2 16 2 577 5 4 50 250 33Small industrial floor and storage5 kN/m2 2.50 150 300 100 12 2 12 1 342 12 2 190 5 2 50 220 19
3.50 200 400 125 12 2 16 2 593 12 2 12 1 329 5 2 50 250 234.50 250 500 150 12 2 16 4 923 12 2 12 3 513 5 2 50 250 30
Horizontal span
Roof 3.00 150 300 100 12 2 12 2 429 12 2 10 1 238 5 2 50 220 221kN/m2 4.00 200 400 125 12 2 12 4 650 12 2 10 2 239 5 2 50 250 27
5.00 250 500 150 12 2 16 4 944 12 2 12 3 524 5 2 50 250 33
Live Load
Width Total height Dia. 1 Number Dia. Number Total Dia. 1 Number Dia. 2 Number Total Dia.
(mm) (mm) (mm) (mm) basic bar (mm) min. mm2 (mm) basic bar (mm) min. mm2 (mm) mini maxiDomestic floor 3.00 250 300 100 12 2 12 2 377 12 2 10 2 314 5 2 50 220 22
1.50 kN/m2 4.00 250 400 125 12 2 16 2 601 12 2 12 3 501 5 4 50 250 275.00 350 450 150 12 2 16 4 1,025 12 2 16 3 854 5 4 50 250 33
Office floor 3.00 200 350 100 12 2 12 1 343 12 2 10 1 286 5 2 50 250 20
2.50 kN/m2 4.00 350 400 125 12 2 16 3 677 12 2 12 3 565 5 4 50 250 275.00 400 500 150 12 2 16 4 1,027 12 2 16 3 856 5 4 50 250 33
Small industrial floor and storage
5 kN/m2 2.50 250 300 100 12 2 10 1 309 12 2 10 1 257 5 2 50 220 193.50 300 400 125 12 2 12 3 568 12 2 12 2 473 5 4 50 250 234.50 400 500 150 12 2 16 4 940 12 2 16 3 783 5 4 50 250 30
Horizontal span
Roof 3.00 250 300 100 12 2 10 2 360 12 2 10 1 300 5 2 50 220 221kN/m2 4.00 300 400 125 12 2 12 3 581 12 2 12 3 257 5 4 50 250 27
5.00 350 500 150 12 2 16 4 884 12 2 16 3 736 5 4 50 250 33
Live Load
Width Total height Dia. 1 Number Dia. Number Total Dia. 1 Number Dia. 2 Number Total Dia.
(mm) (mm) (mm) (mm) basic bar (mm) min. mm2 (mm) basic bar (mm) min. mm2 (mm) mini maxi
Domestic floor 3.00 150 350 100 12 2 10 1 250 12 2 208 5 2 50 250 201.50 kN/m2 4.00 200 400 125 12 2 12 3 447 12 2 12 2 372 5 2 50 250 27
5.00 250 500 150 12 2 16 3 650 12 2 16 2 542 5 4 50 250 33
Office floor 3.00 150 350 100 12 2 12 1 264 12 2 220 5 2 50 250 20
2.50 kN/m2 4.00 200 400 125 12 2 16 2 477 12 2 12 2 398 5 4 50 250 275.00 250 500 150 12 2 16 3 693 12 2 16 2 577 5 4 50 250 33
Small industrial floor and storage5 kN/m2 2.50 150 300 100 12 2 223 12 2 186 5 2 50 220 19
Main reinforcement
Main reinforcement
Main reinforcement
Top steel on bearing
Top steel on bearing
Top steel on bearing
Top steel on bearing
Beam # 2
Beam # 3
Beam # 4
Beam # 1
Slabthick.
Slabthick.
Slabthick.Beam maximum
span (metres)
Beam section
Nb vert.Bar/stir.
Space (mn) Totalstirrup
Vert. stirrups
Vert. stirrups
Nb vert.Bar/stir.
Space (mn) Totalstirrup
Beam maximumspan (metres)
Beam section
Space (mn)
Vert. stirrups
Nb vert.Bar/stir.
Main reinforcementSlabthick. Total
stirrup
Beam maximumspan (metres)
Beam section
Beam maximumspan (metres)
Beam section Vert. stirrups
Nb vert.Bar/stir.
Space (mn) Totalstirrup
Table B7-3 Typical reinforcement for concrete beams - 2 ways slab and HRsteel grade 420
Live Load
Width Total height Dia. 1 Number Dia. 2 Number Total Dia. 1 Number Dia. 2 Number Total Dia.
(mm) (mm) (mm) (mm) basic bar (mm) min. mm2 (mm) basic bar (mm) min. mm2 (mm) mini maxi
Domestic floor 3.00 250 300 100 12 2 12 2 337 12 2 187 5 2 50 220 221.50 kN/m2 4.00 250 400 125 12 2 12 3 534 12 2 10 2 297 5 4 50 250 27
5.00 350 450 150 12 2 16 4 915 12 2 16 2 508 5 4 50 250 33Office floor 3.00 250 300 100 12 2 12 2 365 12 2 203 5 2 49 220 222.50 kN/m2 4.00 300 350 125 12 2 12 4 677 12 2 12 2 376 5 4 50 250 27
5.00 350 450 150 12 2 16 4 1,000 12 2 16 2 555 5 4 50 250 33Small industrial floor and storage
5 kN/m2 2.50 250 300 100 12 2 10 1 276 12 2 153 5 2 50 220 193.50 300 350 125 12 2 12 3 580 12 2 12 1 322 5 4 50 250 234.50 350 400 150 12 2 16 4 1,033 12 2 16 2 574 5 4 50 250 30
Horizontal spanRoof 3.00 250 300 100 12 2 12 1 323 12 2 179 5 2 50 220 221kN/m2 4.00 300 350 125 12 2 12 3 592 12 2 12 1 440 5 4 50 250 27
5.00 350 400 150 12 2 16 4 979 12 2 16 2 544 5 4 50 250 33
Live Load
Width Total height Dia. 1 Number Dia. Number Total Dia. 1 Number Dia. 2 Number Total Dia.
(mm) (mm) (mm) (mm) basic bar (mm) min. mm2 (mm) basic bar (mm) min. mm2 (mm) mini maxiDomestic floor 3.00 150 350 100 12 2 219 12 2 122 5 2 50 250 20
1.50 kN/m2 4.00 200 400 125 12 2 12 2 399 12 2 222 5 2 50 250 275.00 250 500 150 12 2 12 4 578 12 2 12 1 321 5 2 50 250 33
Office floor 3.00 150 350 100 12 2 231 12 2 128 5 2 50 250 20
2.50 kN/m2 4.00 200 400 125 12 2 12 2 424 12 2 10 1 235 5 2 50 250 275.00 250 500 150 12 2 12 4 616 12 2 12 1 342 5 4 50 250 33
Small industrial floor and storage5 kN/m2 2.50 150 300 100 12 2 199 12 2 111 5 2 50 220 19
3.50 200 400 125 12 2 10 2 350 12 2 195 5 2 50 250 23
4.50 250 500 150 12 2 12 3 547 12 2 12 1 304 5 2 50 250 30Horizontal span
Roof 3.00 150 350 100 12 2 213 12 2 119 5 2 50 250 20
1kN/m2 4.00 200 400 125 12 2 12 2 387 12 2 359 5 2 50 250 275.00 250 450 150 12 2 12 4 618 12 2 12 1 343 5 2 48 250 34
Live Load
Width Total height Dia. 1 Number Dia. Number Total Dia. 1 Number Dia. 2 Number Total Dia.
(mm) (mm) (mm) (mm) basic bar (mm) min. mm2 (mm) basic bar (mm) min. mm2 (mm) mini maxi
Domestic floor 3.00 250 300 100 12 2 220 12 2 183 5 2 50 220 221.50 kN/m2 4.00 250 400 125 12 2 12 2 356 12 2 12 1 297 5 4 50 250 27
5.00 350 450 150 12 2 12 4 607 12 2 12 3 506 5 4 50 250 33
Office floor 3.00 250 300 100 12 2 10 1 243 12 2 202 5 2 49 220 222.50 kN/m2 4.00 300 350 125 12 2 12 2 451 12 2 12 2 376 5 4 50 250 27
5.00 350 450 150 12 2 16 3 667 12 2 12 4 555 5 4 50 250 33Small industrial floor and storage5 kN/m2 2.50 250 300 100 12 2 180 12 2 150 5 2 50 220 19
3.50 300 350 125 12 2 10 2 386 12 2 10 2 321 5 4 50 250 234.50 350 400 150 12 2 12 4 685 12 2 12 3 571 5 4 50 250 30
Horizontal span
Roof 3.00 250 300 100 12 2 210 12 2 175 5 2 50 220 221kN/m2 4.00 300 350 125 12 2 10 3 393 12 2 12 1 358 5 4 50 250 27
5.00 350 400 150 12 2 12 4 649 12 2 12 3 541 5 4 50 250 33
Live Load
Width Total height Dia. 1 Number Dia. Number Total Dia. 1 Number Dia. 2 Number Total Dia.
(mm) (mm) (mm) (mm) basic bar (mm) min. mm2 (mm) basic bar (mm) min. mm2 (mm) mini maxiDomestic floor 3.00 150 350 100 12 2 146 12 2 122 5 2 50 250 201.50 kN/m2 4.00 200 400 125 12 2 10 1 265 12 2 221 5 2 50 250 27
5.00 250 500 150 12 2 12 2 386 12 2 12 1 321 5 4 50 250 33Office floor 3.00 150 350 100 12 2 154 12 2 128 5 2 50 250 20
2.50 kN/m2 4.00 200 400 125 12 2 10 1 282 12 2 10 1 235 5 4 50 250 275.00 250 500 150 12 2 12 3 411 12 2 12 1 342 5 4 50 250 33
Small industrial floor and storage
5 kN/m2 2.50 150 300 100 12 2 133 12 2 111 5 2 50 220 19
Main reinforcement
Main reinforcement
Main reinforcement
Top steel on bearing
Top steel on bearing
Top steel on bearing
Top steel on bearing
Beam # 2
Beam # 3
Beam # 4
Beam # 1
Slabthick.
Slabthick.
Slabthick.Beam maximum
span (metres)
Beam section
Nb vert.Bar/stir.
Space (mn) Totalstirrup
Vert. stirrups
Vert. stirrups
Nb vert.Bar/stir.
Space (mn) Totalstirrup
Beam maximumspan (metres)
Beam section
Space (mn)
Vert. stirrups
Nb vert.Bar/stir.
Main reinforcementSlabthick. Total
stirrup
Beam maximumspan (metres)
Beam section
Beam maximumspan (metres)
Beam section Vert. stirrups
Nb vert.Bar/stir.
Space (mn) Totalstirrup
5.1.2.4.2 Form-work
Beams shall be formed by form-work on three sides.
The bottom form-work must be rigid enough to support the weight of the structure, the two othersides and the rigours. This bottom form support shall remain in place 4weeks minimum.
5.1.2.4.3 Reinforcement
For horizontal and vertical reinforcement see table B-7 (1 to 4) and Figures B-17 to 21.
5.1.2.4.4 Concrete
Beams shall be filled with 1:1:1 nominal mix (refer to table B 1). The concrete shall be properlycompacted and poured at one time.
5.1.3 Framed structure See next editionto be published
Fig C1 Wall height
H=
Hei
ght
H=
Hei
ght
1 roof load1 roof load1 floor load
5.2 Timber
5.2.1 Identification & Grade.
See characteristics in paragraph "Basic Materials/Timber".
5.2.2 Exterior walls.
Exterior walls of wood-frame construction shall be designed and constructed in accordance withthe provisions of this chapter.
5.2.2.1 Stud spacing.
In bearing walls, studs, which are not more than 3m in height shall be, spaced not more than isspecified in the following Table C-10
Table C-10 Maximum stud spacing
Stud size Supporting roofand ceiling only
Supporting on floor,roof and ceiling
Supporting one flooronly
50 x 100mm 600mm 400mm 600mm
50 x 150mm 600mm 600mm 600mm
75 x 100mm 600mm 600mm 600mm
5.2.2.2 Top plate.
Wood stud walls shall be capped with a double top plate installed to provide overlapping atcomers and intersections with bearing partitions. See figure C-3.
Any joints in top plates shall be offset at least 600 mm
5.2.2.3 Bearing studs.
Where floor or roof framing members is spaced more than 400mm on centre and the bearingstuds below are spaced 600mm on centre, such members shall bear within 120mm of the studsbeneath.
Fig C2 Top plate framing to accommodate piping
1.5mm metal tieacross and to eachside of the notch
Exterior or bearing wall
Pipe
Top plates
Notch greater than 50%
Fig C3 Typical wall, floor and roof framing
First storey
Rafters and ceiling joistsor approved roof truss
Top plate
Wall studSee drilling and andnotching provisions
Bottom plateBand joist or blocking
Top plate
1/3 span 1/3 span
Joist may be cutor notched between
these limits
Joist nailed to stud
Bearing wall
Bottom plate
Crawl space orbasement foundation
Slab on gradefoundation
SubfloorLap joists 75mmminimum
Joist
Sill plate
Platform framing Balloon framing
Floor joistSee drilling and andnotching provisions
5.2.2.4 Stud length
Table C-11 Maximum allowable length of wood studs
On centre spacingHeight(m)
600m 400mm 300mm 200mm
Supporting a roof only
>3m 50 x 100mm 50 x 100mm 50 x 100mm 50 x 100mm
3.6m 50 x 150mm 50 x 100mm 50 x 100mm 50 x 100mm
4.2m 50 x 150mm 50 x 150mm 50 x 150mm 50 x 100mm
Supporting one floor and a roof
>4.2m 50 x 150mm 50 x 150mm 50 x 150mm 50 x 150mm
Supporting two floors and a roof
>4.2m 50 x 150mm 50 x 150mm 50 x 150mm 50 x 150mm
5.2.2.5 Bottom (sole) plate.
Studs shall have full bearing on a nominal 40mm or larger plate or sill having a width at least equalto the width of the studs.
5.2.3 Interior load bearing walls.
Interior load-bearing walls shall be constructed, framed and fire-stopped as specified for exteriorwalls.
5.2.4 Interior non-bearing walls.
Interior non-bearing walls shall be permitted to be constructed with
- 50mm by 75mm studs spaced 600 mm on centre or, when not part of a braced wall line,
- 50mm by 100mm flat studs spaced at 400mm on centre.
Interior non-bearing walls shall be capped with at least a single top plate.
5.2.5 Drilling and notching-studs.
Any stud in an exterior wall or bearing partition may be cut or notched to a depth not exceeding 25percent of its width.
Studs in non bearing partitions may be notched to a depth not to exceed 40 percent of a singlestud width.
Any stud may be bored or drilled, provided that the diameter of the resulting hole is no greaterthan 40 percent of the stud width, the edge of the hole is no closer than 20mm to the edge of the stud,and the hole is not located in the same section as a cut or notch.
5.2.5.1 Drilling and notching of top plate.
When piping or ductwork is placed in or partly in an exterior wall or interior load-bearing wall,necessitating a cutting of the top plate by more than 50 percent of its width, a galvanised metal tie notless than 1.37 mm thick (16 gage) and 40mm wide shall be fastened to each plate across and to eachside of the opening with not less than six 16d nails.
5.2.6 Headers.
For header spans see Tables on floor section.
5.2.6.1 Wood structural panel box headers.
Wood structural panel box headers shall be constructed in accordance with following Table C-12
Table C-12 Maximum spans for wood structural panel box header
House depth in mHeaderconstruction
Headerdepth
In mm7.5m 8m 8.5m 9m 9.5m
225mm 1.2m 1.2m 0.9m 0.9m -Woodstructuralpanel one
side450mm 1.5m 1.5m 1.2m 0.9m 0.9m
225mm 2.1m 1.5m 1.5m 1.2m 0.9mWoodstructural
panel bothsides
450mm 2.4m 2.4m 2.1m 2.1m 1.8m
5.2.6.2 Non-bearing walls.
Load-bearing headers are not required in interior or exterior non-bearing walls. A single flat 50mmby 100mm member may be used as a header in interior or exterior non bearing walls for openings upto 2.4m in width if the vertical distance to the parallel nailing surface above is not more than 600mm.
For such non bearing headers, no cripples or blocking are required above the header.
5.2.7 Cripple walls.
Foundation cripple walls shall be framed of studs not less in size than the studding above. Whenexceeding 1.2m in height, such walls shall be framed of studs having the size required for anadditional story. See figure C4.
5.2.7.1 Bracing.
Cripple walls shall be braced with an amount and type of bracing as required for the wall aboveplus an additional 15 percent of braced wall length or a maximum braced wall panel spacing to 5.5m.
Cripple walls with a stud height less than 350mm shall be sheathed on at least one side with awood structural panel that is fastened to both the top and bottom plates, or the cripple walls shall beconstructed of solid blocking. Cripple walls shall be supported on continuous foundations.
5.2.8 Wall bracing.
Braced wall panels, exterior walls, and required interior braced wall lines shall be constructed inaccordance with this Section. The braced wall panels in the braced wall lines in each story of thebuilding shall be constructed of a series of one or more braced wall panels.
5.2.8.1 Braced wall lines.
Braced wall lines shall consist of braced wall panels, which meet the requirements for location,method and amount of bracing specified in following table.
Braced wall panels which are counted as part of a braced wall line shall be in line, except thatoffsets out-of-plane of up to 1200mm shall be permitted between adjacent wall panels, provided thatthe total out-to-out offset dimension in any braced wall line is not more than 2400mm Braced wallpanels shall begin no more than 2400mm from each end of a braced wall line.
Fig C4 Framing details
Sill plate
Floor joist
Sub floor
Foundation wall studs
Anchor bolts embedded in foundation
FoundationCripple wall
Wall sruds
Jack studs or trimmers
Header- see table
Single or doubletop plate
Fireblockaround pipe
Stagger joints 100mmor use splice plates
Bo
ttom
pla
te
So
lidbl
ocki
ng
Corner and partition posts
25x 100mm diagonal bracelet into studs
Table C-13 ADJUSTMENT OF BRACING AMOUNTS FOR INTERIOR BRACED WALL LINESACCORDING TO BRACED WALL LINE SPACING
Braced Wall Line Spacing Multiply Bracing Amount by:
Meter Coefficient
4.5m or less 0.6
6m 0.8
7.5m 1.0
9m 1.2
10.5m 1.4
Exterior braced wall lines shall have a braced wall panel located at each end of the braced wallline.
1. Linear interpolation is permissible.
2. The adjustment is limited to the larger spacing between braced wall lines to either side of aninterior braced wall line.
5.2.8.1.1 Sheathing attachment.
Fastening of braced wall panel sheathing shall be nailed with 8d minimum.
Adhesive attachment of wall sheathing is not permitted.
5.2.8.2 Braced wall panel construction methods.
The construction of braced wall panels shall be in accordance with one of the following methods:
1. Nominal 25mm by 100mm continuous diagonal braces let in to the top and bottom plates andthe intervening studs or approved metal strap devices installed in accordance with the manufacturer'sspecifications.
The let-in bracing shall be placed at an angle not more than 60 degrees or less than 45 degreesfrom the horizontal.
2. Wood boards of 16mm net minimum thickness applied diagonally on studs spaced a maximumof 600mm on centre.
3. Wood structural panel sheathing with a thickness not less than 8mm for 400mm stud spacingand not less than 10mm for 600mm stud spacing.
4. 13mm or 19mm thick structural fibre board sheathing applied vertically on studs spaced amaximum of 400mm on centre.
5.2.8.3 Length of braced panels.
For methods 2,3 and 4 above, each braced wall panel shall be at least 1200mm in length,covering a minimum of three stud spaces where studs are spaced 400mm on centre and covering aminimum of two stud spaces where studs are spaced 600mm on centre.
5.2.8.4 Panel joints.
All vertical joints of panel sheathing shall occur over studs.
Horizontal joints in braced wall panels shall occur over blocking of a minimum of 40mm thickness.
5.2.8.5 Connection
Braced wall panel sole plates shall be fastened to the floor framing and top plates shall beconnected to the framing above.
Sills shall be fastened to the foundation or slab.
Where joists are perpendicular to the braced wall lines above, blocking shall be provided underand in line with the braced wall panel.
5.2.8.6 Wall anchorage.
Braced wall line sills shall be anchored to concrete or masonry foundations.
Plate washers, a minimum 6mm x 50mm x 50mm in size, shall be provided between thefoundation sill plate and the nut.
5.2.8.7 Interior Braced wall panel
Interior braced wall lines shall be fastened to floor and roof framing.
1. Floor joists parallel to the top plate shall be toe nailed to the top plate with at least 8d nailsspaced a maximum of 150mm on centre.
2. Top plate laps shall be face nailed with at least 8-16d nails on each side of the splice
5.2.9 Structure
See figures. A1-7 and A1-8
a) No timber frame members should be less than 100mm in width.
b)At all corners and intersections, uprights should be not less than 100mmx 100mm or 2 membersof 50mm x 100mm each bolted together. The posts should be fixed to the sills or floor beams bydowel or metal cleats.
c)Intermediate uprights should be not less than 100mm x 50mm and spaced at not more than600mm.
d)The corners of all rooms and intersections should be braced with timber members not less than50mm x 100mm and shall be jointed to the upright in such a manner as to leave the upright whole.
e)The upper sills and wall plates at the outer corners and intersections can be tied with straps atleast 225mm x 225mm x 6mm secured with 4 # 10mm diameter coach screws not less than 65mmlong.
f)Alternatively, bracing may maybe effected by 50mm x 100mm diagonal timber struts in allcorners. It is important to have a tight connection between the wall plates and posts.
(g)The clear height of a wall should not be greater than 3m on the basis of structural calculationsshowing that the wall framing as designed is adequately supported and can withstand the horizontalimposed loads including wind and earthquakes.
5.2.10 Cladding
a)The cladding of all external walls must be of approved weatherproof material. All cladding mustbe nailed securely to each framing member.
b)Where plaster is used as the cladding, it should consist of not less than two coats applied tometal laths which shall be securely fastened to the weather proof backing.
c)The metal laths may consist of expanded metal sheets, "hyrib" or other standard materials. Suchmaterial must be used in accordance with the manufacturer's instructions.
d) The first or scratch coat of plaster shall be not less than 12mm thick and shall be kept moist by
e) Interior walls may be covered by any approved kind of interior partition boards or with plaster asdescribed above.
Fig D1-1 Steel frame typical
Steel haunch
Steel column
Steel beam profiles
Anchors Anchors
Fig D1-3 Beam framing
Moment splice at ridge(Field bolted)
Stiffener if required
Bolted moment splice
Shear splices
Shear connections
Erection seat
Fig D1-4 Column base plates and connection
Shop weldor bolt or bolt
Shop weld
Weld as required
Erection clearance
Erectionpin hole(optional)
Shim asrequired
5.3 Metal
5.3.1 MS beams and profiles
5.3.1.1 General
For steel framed buildings, two systems are generally used for walls. These are hollow concreteblock walls or metal cladding.
5.3.1.1.1 Masonry walls
a) When concrete walls are used, the information given in Section "Masonry block wall" isapplicable. There are some minor differences concerning the anchoring of the wall reinforcement. Thevertical steel is anchored to the footing in the normal manner and anchored at the top by welding to thelongitudinal beam, or fixed to a concrete beam constructed on top of the walls.
b) The horizontal reinforcement is welded to the web of the columns. If the columns are encasedin concrete the reinforcement can be carried to the face of the steel column.
c) Care must be taken to fix these walls to the steel frames so as to provide lateral continuity to thewalls and to prevent the wall from collapsing either under the shaking from an earthquake or from thepressures due to hurricane winds.
d) It is however, sometimes necessary to install a flexible joint between the block wall and thesteel column where the walls have not been used to provide lateral stability. In this event the steelframe must be adequately braced to accommodate the lateral loads without collapse.
5.3.1.1.2 Metal Cladding
a) Where metal cladding is used, Z-purlins are attached to the columns with suitable fixing.
b) The vertical siding, as the sheeting is then called, is attached to the Z-purlins in the normalmanner employed for roofs. Fixings made in the valleys rather than on the crowns would providegreater hurricane resistance.
c) Care must be taken to prevent leaks.
5.4 Mixed construction
See figure A2-1a for Basic 1 or 2 level house, and A2-1b for Mixed 1 or 2 level house and typicalarrangement.
Details are on Figures B-17 (1 and 2) for typical cross sections.
Fig B14 & B15 Details of ground floor slab on grade and suspended groundfloor slab.
100mm slab minimum
150mm blockwork
300mm minimumgrade
450
600mm min
r.c. tie beam
50mm sand blinding
marl in 100mm layerswell compacted gravel or
150mm blockworkminimum
0.15mm polythene damp proof course
600 mm minimum
Crawl space 300 mm minimum
200mm blockwork
100mm slab minimum (see table)
150mm blockwork
Fig B18 Slabs and beams typical arrangements
Beam #1
Beam #1 Beam #1 Beam #1
Beam #2
Beam #3
Beam #4
Beam #3
Beam #4
Beam #3
Beam #2
Beam #2
Beam #1
Beam #1
Beam #2 Beam #4
Beam #3 Beam #3 Beam #3
Beam #4 Beam #3 Beam #3 Beam #3
Beam #6
Beam #5
Beam #6 Beam #8
Beam #7 Beam #7
Beam #2
Beam #4
Beam #2 Beam #4 Beam #4
Beam #1 Beam #1 Beam #1
Beam #1 Beam #1
Beam #1 Beam #1 Beam #1
Beam #1 Beam #3 Beam #3 Beam #3
Beam #4 Beam #4
Beam #2 Beam #4 Beam #4
Beam #2
Beam #8 Beam #8
Beam #6
Beam #6 Beam #8 Beam #8
Beam #6 Beam #8 Beam #8 Beam #8
Beam #6 Beam #8 Beam #8
Beam #8
Beam #6
Beam #5 Beam #7 Beam #7
Beam #5 Beam #7 Beam #7
Beam #6
6 Floor systems
6.1 Concrete floor slabs
6.1.1 Layout
6.1.1.1 Slab on grade
For slab on grade (see figure B-14) the following shall be observed: -
a) The concrete floor shall be a minimum of 100 mm thick and supported on not less than 200 mm ofcompacted hardcore, gravel or approved granular material. It is recommended that the fill materialneeded not be more than 900 mm deep and be of well compacted selected material.
b) Where fills greater than 900 mm are required, the floor shall be constructed as a suspendedreinforced concrete slab. This procedure will prevent cracking of the concrete floor slab due toimperfectly compacted fill.
c) The finished surface of the floor shall be located not less than 300 mm above finished groundlevel. On a sloping site, the floor shall be at least 300 mm above the ground at any point at the nearestpoint relative to the floor.
6.1.1.2 Damp proof course
6.1.1.2.1
A damp proof course shall be provided to prevent rising water through the floor slab andload bearing walls.
6.1.1.2.2
Where polythene is used it shall be at least 0.15 mm thick and shall be laid over thecompacted floor foundation. This material shall be used with caution as it easily broken. Laps in thedamp proof membrane shall not be less than 150 mm.
6.1.1.2.3
Alternative damp proof course applications
a) Asphalt
b) Concrete screed
6.1.1.3 Reinforcement
6.1.1.3.1
The floor slab on grade shall be reinforced with welded wire mesh 150 mm 150 mm 3mm. The mesh shall be located 25 mm from the top of the slab and care shall be taken during pouringthat this location is maintained.
6.1.1.3.2
The mesh shall be tied to the ground beams where such beams are used. Minimum laps in themesh shall be 150 mm.
6.1.1.4 Suspended Slab
6.1.1.4.1 Suspended slab
For suspended slab (see figure B-15) the following shall be observed: -
a) The concrete floor slab shall be a minimum of 100 mm thick and conform to table B-4.
b) The maximum span shall conform to table B-4.
c) As a protection against flooding, the finished surface of the floor shall be located no less than 300mm above ground level. On a sloping site, the floor shall be at least 300 mm above the ground at anypoint at the nearest point relative to the floor.
Table B-4 Typical reinforcement for two way slabs
Maximum span Slab thicknessDia. Space Dia. Spacing Dia. Spacing
(mm) (mm) (mm) (mm) (mm) (mm)Domestic floor 3.00 100 10 150 10 250 10 2501.50 kN/m2 4.00 125 12 150 12 250 10 250
5.00 150 12 120 12 240 10 250
Office floor 3.00 100 10 150 10 250 10 2502.50 kN/m2 4.00 125 12 150 12 250 10 250
5.00 150 12 120 12 240 10 250
Small industrial floor and storage5 kN/m2 2.50 100 10 120 10 240 10 250
3.50 125 12 120 12 240 10 2504.50 150 12 100 12 200 10 250
Horizontal spanRoof 3.00 100 10 200 10 250 10 2501kN/m2 4.00 125 10 150 10 250 10 250
5.00 150 12 150 12 250 10 250
Note: Steel rods are MS rods and Concrete is Grade "C" (see Table B1)Ratio (Slab Lengh / Slab Width) between 0.8 to 1.25Slab thickness min 100mmTop center steel lengh = 2 m min. 2000mm minTop edge steel lengh = 1.2m min. 200mm 1000mm min
Top edge steelTop center steelSlab location
Live Load (metres) (mm)
Main reinforcement (2 ways)
Fig B19-1 Beam reinforcement - Typical arrangement Mild Steel
2 rods
3 rods
4 rods
5 rods
6 rods
Basic 6mm dia. stirrup
and 4x12mm bar
Additionnal stirrup if 3 barsto be maintained
Additionnal bar to be maintained
7 rods
8 rods
9 rods
or
Additionnal bar See table B 7-1 or B 7-2
1 bar as Table
2 bars as Table
3 bars as Table
4 bars as Table
5 bars as Table
6 bars as Table
7 bars as Table
no bar added as Table
Fig B19-2 Beam reinforcement - Typical arrangement HR Steel
or4 rods
no bar added as Table
Additionnal bar See table B 7-3 or B 7-4
2 rods
3 rods2 bars as Table
1 bar as Table
7 rods
5 rods
6 rods
5 bars as Table
4 bars as Table
3 bars as Table
Additionnal bar to be maintained
to be maintainedAdditionnal stirrup if 3 bars
Basic 6mm dia. stirrup
and 4x10mm bar
Fig B20 Concrete beams (Middle & Side)
Span
Total height
WidthWidth
min 75mm max. 200mm
Total number stirrups
Assembly rods
Main reinforcementMidle top reinforcement
Type of stirrup
Column 250mm min
45°
Rod details
minimum lap see table B-3
Fig B21 Beam sections
6.1.1.4.2 Reinforcement
The minimum requirement for the reinforcement shall conform to table B-4.
6.1.2 Finishing
The slab shall be floated immediately after pouring as this produces a durable surface.Alternatively, a sand cement screed not less than 20 mm thick may be applied to roughened surface ofthe concrete. The surface shall be cleaned and washed before applying the screed. A screed ofproportions of 1 part cement to 4 parts sand (by volume) is acceptable.
6.1.3 Services
All pipes and conduits for services shall be laid and arranged so that the required concretecover to the reinforcement is maintained.
NOTE Most structures within the scope of these guidelines would have floor slabs on compacted granularmaterial; but on sloping sites, floor slabs may have to be suspended. The reinforcement set out above will providea safe suspended floor or roof. Professional assistance should be sought on the size and placement ofreinforcement for situations other than those described.
Fig C5 Floor construction
Double joist under bearingpartitions
Foundation
Sill plate
Solid blocking
Band, rim or header joist
Wood structural panel
Optional finish floor
Botom wall plate
Studs
Subfloor orfloor sheating
Sill plates
Joists
pipe in partition
Bridging
6.2 Timber
6.2.1 Identification & Grade.
See characteristics in paragraph "Basic Materials/Timber".
6.2.2 General
6.2.2.1 Design and construction.
Floors shall be designed and constructed in accordance with the provisions of this chapter andfigure C5.
6.2.2.2 Allowable joist spans.
Spans for floor joists shall be in accordance with Table C-2
Table C-2 Floor joist span for common lumber species
Dead load = 1kN/m2 and Live load 1.5kN/m2
50x150mm 50x200mm 50x250mm 50x300mm
Joist spacing
Maximum floor joist spans in metre
300mm 3.3m 4.2m 5.1m 6m
400mm 3m 3.6m 4.5m 5.2m
500mm 2.6m 3.3m 4m 4.6m
600mm 2.3m 3m 3.6m 4.2m
6.2.2.3 Joists under bearing partitions.
Joists under parallel bearing partitions shall be doubled or a beam of adequate size to support theload shall be provided. Double joists, which are separated to permit the installation of piping or vents,shall be full depth solid blocked with lumber not less than 50mm in nominal thickness spaced not morethan 1200mm on centre.
6.2.2.4 Allowable header spans.
The allowable spans of headers shall not exceed the values set forth in Table C-3.
Table C-3 Header spans for exterior bearing walls
Building width in metre
< or = 6m 6m < <8.5m
8.5m < < 11mHeaders
supportingNumber and sizes
of header
Maximum header span in metre
2 - 50x100mm 1m 0.9m 0.8m
2 – 50x150mm 1.6m 1.4m 1.2mRoof and
ceiling
2 – 50x200mm 1.9m 1.7m 1.6m
2 - 50x100mm 0.9m 0.8m 0.7m
2 – 50x150mm 1.3m 1.2m 1.1mRoof, ceiling
& 1 centrebearing floor 2 – 50x200mm 1.7m 1.5m 1.35m
2 - 50x100mm 0.8m 0.7m 0.6m
2 – 50x150mm 1.15m 1.1m 0.9mRoof, ceiling
& 1 clear spanfloor 2 – 50x200mm 1.5m 1.3m 1.15m
Table C-4 Header spans for interior bearing walls
Building width in metre
< or =6m
6m < <8.5m
8.5m < < 11mHeaders and
girders supportingNumber and
sizes of header
Maximum header span in metre
One floor only 2 - 50x100mm 0.95m 0.8m 0.7m
One floor only 2 – 50x150mm 1.35m 1.15m 1.05m
One floor only 2 – 50x200mm 1.75m 1.5m 1.35m
One floor only 2 – 50x250mm 2.1m 1.8m 1.55m
One floor only 2 – 50x300mm 2.4m 2.1m 1.9m
Fig C6 Joist cutting, notching and drilling
L/3 L/3
L
D
no notchespermited
D/6
max
i
D/6
ma
xi
D
D/4
max
i
D/4
ma
xi
D
maxi D from support
D/3
max
i
D
D/3maxi
50m
mm
ini
50m
mm
ini
Floor joist - center cuts
Floor joist - end cuts
Rafter/ceiling joists
Drilling
6.2.2.5 Bearing.
The ends of each joist, beam or header shall have not less than 50mm of bearing on wood ormetal and not less than 75mm on masonry or concrete.
6.2.2.5.1 Floor systems.
Joists framing from opposite sides over a bearing support shall lap a minimum of 75 mm and shallbe nailed together. A wood or metal splice with strength equal to or greater than that provided by thenailed lap is permitted.
6.2.2.5.2 Joist framing.
Joists framing into the side of a wood header shall be supported by approved framing anchors oron ledger strips not less than nominal 50mm by 50mm.
6.2.2.6 Lateral restraint at supports.
Joists shall be supported laterally at the ends by full-depth solid blocking not less than 50mmnominal in thickness; or by attachment to a header, band or rim joist, or to an adjoining stud; or shallbe otherwise provided with lateral support to prevent rotation.
6.2.2.6.1 Bridging.
Joists exceeding a nominal 50mm x 150mm shall be supported laterally by solid blocking,diagonal bridging (wood or metal), or a continuous 25mm by 75mm strip nailed across the bottom ofjoists perpendicular to joists at intervals not exceeding 2400mm
6.2.2.7 Drilling and notching.
Structural floor members shall not be cut, bored or notched in excess of the limitations specified inthis section. See Figure C-6.
6.2.2.7.1 Engineered wood products.
Cuts, notches and holes bored in trusses, laminated veneer lumber, glue-laminated members or I-joists are not permitted unless the effect of such penetrations are specifically considered in the designof the member.
6.2.2.8 Fastening.
Floor framing shall be nailed or screwed. Where posts and beam or header construction is used tosupport floor framing, positive connections shall be provided to ensure against uplift and lateraldisplacement.
6.2.2.9 Framing of openings.
Openings in floor framing shall be framed with a header and trimmer joists.
When the header joist span does not exceed 1200mm, the header joist may be a single memberthe same size as the floor joist. Single trimmer joists may be used to carry a single header joist that islocated within 900mm of the trimmer joist bearing.
When the header joist span exceeds 1200mm, the trimmer joists and the header joist shall bedoubled and of sufficient cross section to support the floor joists framing into the header. Approvedhangers shall be used for the header joist to trimmer joist connections when the header joist spanexceeds 1800mm.
6.2.2.10 Wood trusses.
6.2.2.10.1 Design.
Wood trusses shall be designed in accordance with approved engineering practice.
The design and manufacture of metal plate connected wood trusses shall comply with ANSI/TPI 1,National Design Standard for Metal Plate Connected Wood Truss Construction.
6.2.2.10.2 Bracing.
Trusses shall be braced to prevent rotation and provide lateral stability in accordance with therequirements specified in the construction documents for the building and on the individual trussdesign drawings.
6.2.2.10.3 Alterations to trusses.
Truss members and components shall not be cut, notched, spliced or otherwise altered in any waywithout the approval of a registered design professional.
Alterations resulting in the addition of load (e.g. HVAC equipment, water heater, water tank etc.),that exceeds the design load for the truss shall not be permitted without verification that the truss iscapable of supporting the additional loading.
6.2.3 Floor sheathing
6.2.3.1 Lumber sheathing.
Maximum allowable spans for lumber used, as floor sheathing shall conform to the following TableC-5
Table C-5 Minimum thickness of floor sheathing
Minimum net thicknessJoist orbeam spacing in
mm Perpendicular to joist Diagonal to joist
400mm 16mm 16mm
600mm 19mm 19mm
Plywood continuous over two or more spans and face grain perpendicular to supports.Unsupported edges shall be tongue and grove or blocked.
6.2.3.1.1 End joints.
End joints in lumber used, as flooring shall occur over supports.
6.2.3.2 Wood structural panel sheathing.
6.2.3.2.1 Identification and grade.
Wood structural panel sheathing used for structural purposes shall be identified by a grade markof certificate of inspection issued by an approved agency.
6.2.3.2.2 Wood structural panel
Where used, wood structural panels shall be of one of the grades specified in Table C-5
When sanded plywood is used as combination sub-floor underlay, the grade shall be as specifiedin Table above.
6.2.3.3 Particleboard.
6.2.3.3.1 Identification and grade.
Particleboard shall conform to ANSI A208.1 and shall be so identified by a grade mark orcertificate of inspection issued by an approved agency.
6.2.3.3.2 Particle board panel.
Where used, particleboard panels shall be of one of the grades specified in Table C-5
6.3 Metal
6.3.1 MS steel beam
MS steel beam structure shall be engineered based on values given by the Design criteria andother characteristics of this code by recognised professional.
Fig B16 Typical hip roof construction
facia board
jack rafter
hip rafterridge board
r.c. ring beam
facia board
jack rafter
hip rafter
ridge beam
rafters
maximum see table B-6
7 Roof assemblies
7.1 Roof structure
7.1.1 Concrete roof structure
Ditto paragraph "Concrete floor slabs".
7.1.2 Timber
7.1.2.1 Layout
7.1.2.1.1
Roofs are generally constructed as one of three common types. These are:
a) hip roofs;
b) gable roofs; or
c) mono roof. (lean-to)
7.1.2.1.2
The gable roof consists of a structural frame made up of a ridge board and (with) rafters.
7.1.2.1.3
The minimum sizes of roof members shall be 25 mm 150 mm for the ridge board and 50 mm 100 mm for the rafters at 800 mm between centres. The same size rafters shall be used for mono-pitched (shed) roofs.
7.1.2.1.4
In the case of the hip roof, hip rafters are introduced into the structural frame as shown infigure B-16.
7.1.2.1.5
The minimum size of the hip rafters shall be 50 mm 150 mm. Table B-5 gives rafter sizes ofmain members constructed of pitch pine.
7.1.2.1.6
The use of timber other than pitch pine at the minimum recommended sizes for pitch pine isacceptable only if it is a stronger timber. Professional advice shall be sought if smaller sizes are usedfor stronger timber or if weaker timber is used. (Table specifying for different types of timber).
7.1.2.1.7
The timber roof sheeting is generally constructed using 25 mm 150 mm tongue-and-grooveboarding, 16 mm plywood or other patented boarding.
7.1.2.1.8
Sheeting may be replaced by a secondary frame of 50 mm 50 mm or 50 mm 100 mm battensfixed to the rafters.
7.1.2.2 Fixings
7.1.2.2.1
The rafters shall be securely fixed to the ring beam at the top of the walls on a wall plate and to theridge board at the crown of the roof.
7.1.2.2.2
The use of patented hurricane clips (rafter ties) for fixing rafters to plates; purlins and ridge boardsshall be used.
Table C5 Maximum roof span for rafter
50x100 50x150 50x200 50x250 50x100 50x150 50x200 50x250 50x100 50x150 50x200 50x250
Calculation based on minimum wood stress of 7,500.00 kN/m2Maximum length of wood 6.00 m minimum calculated span authorised more than 1.50 m
Rough material
Solution 1 minimum live load = 0.60 kN/m2400mm span 3.40 5.10 2.80 4.20 5.60 2.40 3.70 4.90600mm span 2.80 4.10 5.50 2.30 3.40 4.60 5.70 2.00 3.00 4.00 5.00800mm span 2.40 3.60 4.80 2.00 3.00 4.00 4.90 1.70 2.60 3.50 4.30
Solution 2 normal live or climatic load = 1 kN/m2400mm span 2.90 4.30 5.80 2.50 3.80 5.00 2.20 3.40 4.50 5.60600mm span 2.40 3.50 4.70 5.90 2.00 3.10 4.10 5.10 1.80 2.70 3.70 4.60800mm span 2.00 3.10 4.10 5.10 1.80 2.70 3.50 4.40 1.60 2.40 3.20 4.00
Solution 3 climatic load = 1.5 kN/m2400mm span 2.50 3.80 5.00 2.20 3.40 4.50 5.60 2.00 3.10 4.10 5.10600mm span 2.00 3.10 4.10 5.10 1.80 2.70 3.70 4.60 1.70 2.50 3.30 4.20800mm span 1.80 2.70 3.50 4.40 1.60 2.40 3.20 4.00 2.20 2.90 3.60
Dressed material loss of 12mm in all direction in rough sizing of the material
exact sizes 38x88 38x138 38x188 38x238 38x88 38x138 38x188 38x238 38x88 38x138 38x188 38x238
Solution 11 minimum live load = 0.60 kN/m2400mm span 2.60 4.10 5.50 2.10 3.40 4.60 5.80 1.90 2.90 4.00 5.10600mm span 2.10 3.30 4.50 5.70 1.80 2.70 3.70 4.70 1.50 2.40 3.30 4.10800mm span 1.80 2.90 3.90 4.90 1.50 2.40 3.20 4.10 2.10 2.80 3.60
Solution 12 live or climatic load = 1.00 kN/m2400mm span 2.20 3.50 4.70 6.00 1.90 3.00 4.10 5.20 1.70 2.70 3.70 4.60600mm span 1.80 2.80 3.90 4.90 1.60 2.50 3.30 4.20 2.20 3.00 3.80800mm span 1.60 2.50 3.30 4.20 2.10 2.90 3.70 1.90 2.60 3.30
Solution 13 climatic load = 1.50 kN/m2400mm span 1.90 3.00 4.10 5.20 1.70 2.70 3.70 4.60 1.60 2.50 3.30 4.20600mm span 1.60 2.50 3.30 4.20 1.40 2.20 3.00 3.80 2.00 2.70 3.50800mm span 2.10 2.90 3.70 1.90 2.60 3.30 1.70 2.40 3.00
How to use the tablea) choose the coloumns with the type of roof (dead load)b) choose the lignes with the type of exposure (climatic load) and type of wood (rough or dressed)c) with the span required choose the righ solution (rafter spacing and size)
rafter spacing in the left coloumnsize on top of the table
Dead load = 1.50 kN/m3Roof with ceiling and ordinary clay or cement
tiles
Dead load = 1.00 kN/m2Semi light roof with suspended ceiling and
asphalt shingleRafter
spacingSolutions
Dead load = 0.50 kN/m2Light roof with galvanized sheeting
Table C6 Maximum roof span for battens and joist
100x25 50x50 100x50 50x100 50x150 100X150 50x25 100x25 50x50 100x50 50x100 50x150 100X150 50x25 100x25 50x50 100x50 50x100 50x150
Calculation based on minimum wood stress of 7,500.00 kN/m2Maximum span of wood 30 times wood height (to prevent flexion)
750 1500 1500 3000 4500 4500 750 750 1500 1500 3000 4500 4500 750 750 1500 1500 3000 4500Rough material
Solution 1 minimum live load = 0.60 kN/m2400mm batten space 1.20600mm batten space 0.50 1.10 0.40 0.80800mm batten space 0.90 1.80 0.30 0.60 1.20 0.20 0.50 0.90
1000mm batten space 0.60 1.10 0.80 1.60 0.60 1.201250mm batten space 0.40 0.70 1.50 0.50 1.00 2.00 0.40 0.80 1.501500mm batten space 0.50 1.00 0.30 0.70 1.40 0.30 0.50 1.10 2.401800mm batten space 1.40 3.20 1.00 2.20 4.30 0.70 1.702000mm batten space 1.10 2.60 5.10 0.80 1.80 3.50 0.60 1.302500mm batten space 0.70 1.60 3.30 1.10 2.30 0.903000mm batten space 1.10 2.30 0.80 1.60 0.604000mm batten space 0.60 1.30 0.90
Solution 2 normal live or climatic load = 1 kN/m2400mm batten space 1.00600mm batten space 1.20 0.40 0.90 0.30 0.70800mm batten space 0.70 1.30 0.20 0.50 1.00 0.20 0.40 0.80
1000mm batten space 0.80 1.70 0.60 1.30 0.50 1.001250mm batten space 0.50 1.10 2.10 0.40 0.80 1.60 0.30 0.60 1.301500mm batten space 0.40 0.70 1.50 0.30 0.60 1.10 2.50 0.40 0.90 2.001800mm batten space 1.00 2.30 0.80 1.70 3.50 0.60 1.402000mm batten space 0.80 1.90 3.80 0.60 1.40 2.80 1.102500mm batten space 1.20 2.40 0.90 1.80 0.703000mm batten space 0.80 1.70 0.60 1.304000mm batten space 0.90 0.70
Solution 3 exposed climatic load = 1.5 kN/m2400mm batten space 2.00 0.80 0.70 1.30600mm batten space 0.90 1.70 0.30 0.70 0.30 0.60 1.20800mm batten space 0.50 1.00 0.20 0.40 0.80 0.30 0.70 1.30 2.60
1000mm batten space 0.60 1.30 0.50 1.00 0.40 0.80 1.701250mm batten space 0.40 0.80 1.60 0.30 0.60 1.30 0.30 0.50 1.10 2.401500mm batten space 0.30 0.60 1.10 2.50 0.40 0.90 2.00 4.00 0.40 0.70 1.701800mm batten space 0.80 1.70 3.50 1.40 2.80 0.50 1.202000mm batten space 1.40 2.80 1.10 2.30 0.902500mm batten space 0.90 1.80 1.403000mm batten space 1.30 1.00
How to use the tablea) choose the columns with the type of roof (dead load)b) choose the paragraph with the type of exposure (climatic load) and type of space between rafters or trussesc) with the span required choose the righ solution (batten spacing and sizes)
Rafter ortruss
spacingSolutions
Dead load = 0.50 kN/m2Light roof with galvanized sheeting
Dead load = 1.00 kN/m2Semi light roof with suspended ceiling and asphalt shingle
Maximum space forpurlins
Dead load = 1.50 kN/m3Roof with ceiling and ordinary clay or cement tiles
Maximum space forbattens
Maximum space for purlins Maximum space for battens Maximum space forpurlins
Maximum space for battens
7.1.2.2.3
Plywood decking shall be fastened to the purlins or rafters at a spacing of not less than 600 mm.
7.1.2.2.4
Where timber boards are used as decking, the timber shall be secured at each purlin by at leasttwo galvanised head clout nails at least 40 mm long.
Fig D1-2 Z purlin details
Sag steel rod
Z purlin orientation
Fixation type 1 Fixation type 2
spacing
Metal sheet more than {steel 0.50mm (24G) &
Metal sheet less than 0.50mm Clay or concrete tileAsphalt shingle
Decking (plywood or closeboard) 16mm thickness
thickness (26G, 28G and more)
Solution 1
Solution 2 Solution 3 Solution 4
(slope <15° & span <2m) (slope >15° and/or span >2m)
aluminium 0.60mm thickness}
Decking (plywood or closeboard) 20mm thickness
Underlay
Exception for the orientation
OK
Fig D1-6 Z or C steel profile used as rafter
Type ridge
aluminium 0.60mm thickness}
Decking (plywood or closeboard) 16mm thickness
Metal sheet more than {steel 0.50mm (24G) &
Fixation type 1
Solution 1
Fixation type 2
Decking (plywood or closeboard) 20mm thickness
Underlay
thickness (26G, 28G and more)Metal sheet less than 0.50mmSolution 2
Clay or concrete tileSolution 3Asphalt shingle
Solution 4
On ring beam
Rafter
Spacing 400mm or 600mm or 800mm
Fig D1-3 Beam framing
Horizontal beam span
Cantilever
Slope in °
Beam section
Beam type 1
Slope in °
Horizontal beam span
Cantilever
Beam type 2
Hpr
ofi le
2H
pro
file
Wall or concrete beam
Wall or concrete beam
3d
min
imu
m
Typical combinations
Typical assembly forbeam more than 150mm
Table D2 MS beam type 1
Frame spacing in meter 3.00 3.60 4.20 3.00 3.60 4.20 3.00 3.60 4.20 3.00 3.60 4.20
Horizontal beam span in meter 3.60 3.60 3.60 3.60 3.60 3.60 3.60 3.60 3.60 3.60 3.60 3.60
S 3x5.7 (75mm x 60mm) 8.48 Yes
S 4x7.7 (102mm x 68mm) 11.45 Yes Yes Yes Yes Yes Yes Yes Yes YesS 5x10 (127mm x 76mm) 14.87 Yes Yes Yes Yes
W 4x13 (106mm x 103mm) 19.33 Yes Yes
W 6x12 (153mm x 102mm) 17.85W 8x13 (204mm x 102mm) 19.33
Horizontal beam span in meter 4.20 4.20 4.20 4.20 4.20 4.20 4.20 4.20 4.20 4.20 4.20 4.20
S 3x5.7 (75mm x 60mm) 8.48S 4x7.7 (102mm x 68mm) 11.45 Yes Yes Yes Yes Yes Yes
S 5x10 (127mm x 76mm) 14.87 Yes Yes Yes Yes Yes Yes Yes Yes
W 4x13 (106mm x 103mm) 19.33 Yes Yes Yes Yes Yes Yes
W 6x12 (153mm x 102mm) 17.85 Yes YesW 8x13 (204mm x 102mm) 19.33
Horizontal beam span in meter 4.80 4.80 4.80 4.80 4.80 4.80 4.80 4.80 4.80 4.80 4.80 4.80
S 3x5.7 (75mm x 60mm) 8.48S 4x7.7 (102mm x 68mm) 11.45 Yes
S 5x10 (127mm x 76mm) 14.87 Yes Yes Yes Yes Yes Yes YesW 4x13 (106mm x 103mm) 19.33 Yes Yes Yes Yes Yes Yes Yes YesW 6x12 (153mm x 102mm) 17.85 Yes Yes Yes Yes Yes Yes
W 8x13 (204mm x 102mm) 19.33 Yes Yes
Horizontal beam span in meter 5.40 5.40 5.40 5.40 5.40 5.40 5.40 5.40 5.40 5.40 5.40 5.40
S 3x5.7 (75mm x 60mm) 8.48S 4x7.7 (102mm x 68mm) 11.45S 5x10 (127mm x 76mm) 14.87 Yes Yes Yes Yes Yes Yes
W 4x13 (106mm x 103mm) 19.33 Yes Yes Yes Yes Yes Yes
W 6x12 (153mm x 102mm) 17.85 Yes Yes Yes Yes Yes Yes Yes
W 8x13 (204mm x 102mm) 19.33 Yes Yes Yes Yes Yes
Horizontal beam span in meter 6.00 6.00 6.00 6.00 6.00 6.00 6.00 6.00 6.00 6.00 6.00 6.00
S 3x5.7 (75mm x 60mm) 8.48S 4x7.7 (102mm x 68mm) 11.45S 5x10 (127mm x 76mm) 14.87 Yes Yes
W 4x13 (106mm x 103mm) 19.33 Yes Yes Yes
W 6x12 (153mm x 102mm) 17.85 Yes Yes Yes Yes Yes Yes YesW 8x13 (204mm x 102mm) 19.33 Yes Yes Yes Yes Yes Yes Yes Yes
Note: Maximum strengh limited to 175 N/mm2Acceptable solution for profile Yes
Weightin kg/m
Galvanized >0.5mm Galvanized <0.5mm Asphalt shingle Concrete or clay tile
Beam type 1
Solution 1 Solution 2 Solution 3 Solution 4Base on design criteria of Trinidad
& Tobago Building Code
Table D3 MS beam type 2
Frame spacing in meter 3.00 3.60 4.20 3.00 3.60 4.20 3.00 3.60 4.20 3.00 3.60 4.20
Horizontal beam span in meter 4.80 4.80 4.80 4.80 4.80 4.80 4.80 4.80 4.80 4.80 4.80 4.80
S 4x7.7 (102mm x 68mm) 11.45 Yes
S 5x10 (127mm x 76mm) 14.87 Yes Yes Yes Yes Yes Yes Yes
W 4x13 (106mm x 103mm) 19.33 Yes Yes Yes Yes Yes Yes Yes
W 6x12 (153mm x 102mm) 17.85 Yes Yes Yes Yes Yes
W 8x13 (204mm x 102mm) 19.33 Yes Yes
W10x15 (254mm x 102mm) 22.31
Horizontal beam span in meter 5.40 5.40 5.40 5.40 5.40 5.40 5.40 5.40 5.40 5.40 5.40 5.40
S 5x10 (127mm x 76mm) 14.87 Yes Yes Yes Yes Yes Yes
W 4x13 (106mm x 103mm) 19.33 Yes Yes Yes Yes Yes Yes
W 6x12 (153mm x 102mm) 17.85 Yes Yes Yes Yes Yes Yes Yes
W 8x13 (204mm x 102mm) 19.33 Yes Yes Yes Yes
W10x15 (254mm x 102mm) 22.31 Yes
Horizontal beam span in meter 6.00 6.00 6.00 6.00 6.00 6.00 6.00 6.00 6.00 6.00 6.00 6.00
S 5x10 (127mm x 76mm) 14.87 Yes Yes
W 4x13 (106mm x 103mm) 19.33 Yes Yes Yes
W 6x12 (153mm x 102mm) 17.85 Yes Yes Yes Yes Yes Yes Yes
W 8x13 (204mm x 102mm) 19.33 Yes Yes Yes Yes Yes Yes
W10x15 (254mm x 102mm) 22.31 Yes Yes Yes
Horizontal beam span in meter 6.60 6.60 6.60 6.60 6.60 6.60 6.60 6.60 6.60 6.60 6.60 6.60
W 4x13 (106mm x 103mm) 19.33 Yes
W 6x12 (153mm x 102mm) 17.85 Yes Yes Yes Yes Yes Yes
W 8x13 (204mm x 102mm) 19.33 Yes Yes Yes Yes Yes Yes Yes
W10x15 (254mm x 102mm) 22.31 Yes Yes Yes Yes Yes
Horizontal beam span in meter 7.20 7.20 7.20 7.20 7.20 7.20 7.20 7.20 7.20 7.20 7.20 7.20
W 4x13 (106mm x 103mm) 19.33W 6x12 (153mm x 102mm) 17.85 Yes Yes Yes
W 8x13 (204mm x 102mm) 19.33 Yes Yes Yes Yes Yes Yes
W10x15 (254mm x 102mm) 22.31 Yes Yes Yes Yes Yes Yes Yes Yes
Horizontal beam span in meter 7.80 7.80 7.80 7.80 7.80 7.80 7.80 7.80 7.80 7.80 7.80 7.80
W 4x13 (106mm x 103mm) 19.33W 6x12 (153mm x 102mm) 17.85 Yes
W 8x13 (204mm x 102mm) 19.33 Yes Yes Yes Yes
W10x15 (254mm x 102mm) 22.31 Yes Yes Yes Yes Yes
Horizontal beam span in meter 8.40 8.40 8.40 8.40 8.40 8.40 8.40 8.40 8.40 8.40 8.40 8.40
W 4x13 (106mm x 103mm) 19.33W 6x12 (153mm x 102mm) 17.85W 8x13 (204mm x 102mm) 19.33 Yes Yes Yes
W10x15 (254mm x 102mm) 22.31 Yes Yes Yes Yes Yes
Note: Maximum strengh limited to 175 N/mm2for limitation of deflection to 1/240Acceptable solution for profile Yes
Base on design criteria of Trinidad& Tobago Building Code
Concrete or clay tile
Beam type 2
Solution 1 Solution 2 Solution 3 Solution 4Weightin kg/m
Galvanized >0.5mm Galvanized <0.5mm Asphalt shingle
7.1.3 Metal
7.1.3.1 MS steel beam
7.1.3.1.1 Roof structure
See figure D1-5 for details and combinations
See tables D-2 MS beam type 1 and D-3 MS beam type 2 for recommended sections.
7.1.3.2 Cold formed steel
Cold formed steel is composed of galvanised steel sheet 1mm to 1.5mm thickness for C, U and Zsections roll formed profiles.
7.1.3.2.1 Roof structure
Cold formed steel shall be used for purling and rafter as shown in figure D1-2 and D1-6
See tables D-1 Z purlins and D-4 Z or C rafters for recommended sections.
Table D1 Z purlins
Sol 1 Sol 2 Sol 3 Sol 4
Galvanized >0.5mm Galvanized <0.5mm Asphalt shingle Concrete or clay tile
100 mm Z purlin - 1.5mm thicknessSpacing (m)
0.600 3.80 4.00 3.90 3.400.800 3.20 3.40 3.40 2.901.000 2.90 3.10 3.00 2.601.200 2.70 2.80 2.80
Spacing (m)0.600 3.30 3.50 3.40 3.000.800 2.90 3.00 3.00 2.601.000 2.60 2.70 2.701.200 2.50
Spacing (m)0.600 3.10 3.30 3.20 2.800.800 2.70 2.80 2.801.000 2.50 2.501.200
150mm Z purlin - 1.5mm thicknessSpacing (m)
0.600 4.60 4.80 4.80 4.100.800 4.00 4.20 4.10 3.601.000 3.50 3.80 3.70 3.201.200 3.20 3.40 3.40 2.90
Spacing (m)0.600 3.90 4.10 4.10 3.500.800 3.40 3.60 3.50 3.101.000 3.00 3.20 3.10 2.701.200 2.80 2.90 2.90 2.50
Spacing (m)0.600 3.60 3.80 3.70 3.200.800 3.10 3.30 3.20 2.801.000 2.80 2.90 2.90 2.501.200 2.50 2.70 2.60
175mm Z purlin - 1.5mm thicknessSpacing (m)
0.600 4.90 5.20 5.10 4.500.800 4.30 4.50 4.40 3.901.000 3.80 4.00 4.00 3.501.200 3.50 3.70 3.60 3.20
Spacing (m)0.600 4.20 4.40 4.30 3.800.800 3.60 3.80 3.70 3.301.000 3.20 3.40 3.30 2.901.200 2.90 3.10 3.10 2.70
Spacing (m)0.600 3.80 4.00 3.90 3.400.800 3.30 3.50 3.40 2.901.000 2.90 3.10 3.00 2.601.200 2.70 2.80 2.80
Note : On site limit span to 4.80 m
between 30 and 45°
between 30 and 45°
Maximum calculated span for slopebetween 0 and 15°
between 15 and 30°
Base on design criteria of Trinidad &Tobago Building Code
Maximum calculated span for slopebetween 0 and 15°
between 15 and 30°
Metal steel Z purlins
Maximum calculated span for slopebetween 0 and 15°
between 15 and 30°
between 30 and 45°
Table D4 Z or C rafters
Sol 1 Sol 2 Sol 3 Sol 4
Galvanized >0.5mm Galvanized <0.5mm Asphalt shingle Concrete or clay tile
100 mm Z or C rafter - 1.5mm thicknessSpacing (m)
0.400 4.20 4.40 4.40 3.800.600 3.40 3.60 3.60 3.100.800 2.90 3.10 3.10 2.70
Spacing (m)0.400 3.40 3.60 3.60 3.100.600 2.80 2.90 2.90 2.600.800 2.40 2.50 2.50 2.20
Spacing (m)0.400 2.40 2.50 2.50 2.200.600 2.10 2.100.800
150mm Z or C rafter - 1.5mm thicknessSpacing (m)
0.400 5.50 5.70 6.10 5.300.600 4.50 4.70 5.00 4.400.800 3.90 4.10 4.30 3.80
Spacing (m)0.400 4.40 4.60 5.00 4.800.600 3.60 3.80 4.10 3.900.800 3.10 3.30 3.50 3.40
Spacing (m)0.400 3.10 3.20 3.40 3.700.600 2.50 2.60 2.70 3.000.800 2.20 2.30 2.40 2.60
175mm Z or C rafter - 1.5mm thicknessSpacing (m)
0.400 6.10 6.40 6.80 5.900.600 5.00 5.20 5.60 4.900.800 4.30 4.50 4.80 4.20
Spacing (m)0.400 4.90 5.10 5.50 5.400.600 4.00 4.20 4.50 4.400.800 3.50 3.60 3.90 3.80
Spacing (m)0.400 3.50 3.60 3.70 4.100.600 2.80 2.90 3.10 3.400.800 2.50 2.50 2.70 2.90
Note : On site limit span less than 35 profile height
Base on design criteria of Trinidad & TobagoBuilding Code
Maximum calculated horizontal span for slopebetween 15 and 30°
Metal steel Z or C rafters
Maximum calculated horizontal span for slopebetween 15 and 30°
between 30 and 45°
between 45 and 60°
between 45 and 60°
between 30 and 45°
between 30 and 45°
Maximum calculated horizontal span for slopebetween 15 and 30°
between 45 and 60°
7.2 Roof covering
7.2.1 Weather protection
7.2.1.1 General
7.2.1.1.1
Roof decks shall be covered with approved roof coverings secured to the building or structure inaccordance with the provisions of this chapter.
7.2.1.1.2
Roof coverings shall be designed and installed in accordance with this code and the approvedmanufacturer's installation instructions such that the roof covering shall service to protect the buildingor structure.
7.2.1.2 Flashing.
Flashiness shall be installed in such a manner as to prevent moisture entering the wall through thejoints in the coping, through moisture permeable material, at intersections with the roof plane or atparapet wall penetrations.
7.2.1.2.1 Locations.
Flashiness shall be installed at wall and roof intersections; wherever there is a change in roofslope or direction; and around roof openings. Where flashing is of metal, the metal shall be corrosion-resistant with a thickness of not be less than 0.50mm.
7.2.1.3 Coping.
Parapet walls shall be properly coped with non-combustible, weatherproof materials of a width noless than the thickness of the parapet wall.
7.2.1.4 Roof drainage.
Unless roofs are sloped to drain over roof edges, roof drains shall be installed at each low point ofthe roof. Where required for roof drainage, scuppers shall be placed level with the roof surface in awall or parapet. The scupper shall be located as determined by the roof slope and contributing roofarea.
7.2.1.5 Overflow drains and scuppers.
Where roof drains are required, overflow drains having the same size as the roof drains shall beinstalled with the inlet flow line located 50mm above the low point of the roof, or overflow scuppershaving three times the size of the roof drains and having a minimum opening height of 100mm may beinstalled in the adjacent parapet walls with the inlet flow located 50mm above the low point of theadjacent roof.
Overflow drains shall discharge to an approved location and shall not be connected to roof drainlines.
7.2.2 Materials
7.2.2.1 Scope.
The requirements set forth in this section shall apply to the application of roof covering materialsspecified herein.
Roof coverings shall be applied in accordance with this chapter and the manufacturer's installationinstructions.
Installation of roof coverings shall comply with the applicable provisions of this
7.2.2.2 Compatibility of materials.
Roofs and roof coverings shall be of materials that are compatible with each other and with thebuilding or structure to which the materials are applied.
7.2.2.3 Material specifications and physical characteristics.
Roof covering materials shall conform to the applicable standards listed in this chapter. In theabsence of applicable standards or where materials are of questionable suitability, testing by anapproved testing agency shall be required by the code official to determine the character, quality andlimitations of application of the materials.
7.2.2.4 Product identification.
Roof covering materials shall be delivered in packages bearing the manufacturer's identifyingmarks and approved testing agency labels when required. The manufacturer shall accompany withthe same information issued in the form of a certificate or on a bill of lading bulk shipments ofmaterials.
7.2.2.5 Roof covering application.
Roof coverings shall be applied in accordance with the applicable provisions of this section andthe manufacturer's installation instructions.
7.2.3 Requirements for material roof covering
7.2.3.1 Metal sheeting
7.2.3.1.1 Steel sheeting
Where the cladding is protected steel sheeting its thickness shall not be less than
0.625 mm (24G) when timber battens or purlins shall be used as supporting members withspan no more than 1200mm.
0.475 mm (26G) when close board or 16mm plywood sheathing shall be used as support.
7.2.3.1.2 Aluminium sheeting
Aluminium sheeting is not recommended unless 0.60mm (22G) sheeting is available andunless the fixings supplied have been tested to withstand hurricane force winds.
7.2.3.1.3 Fastening systems
Protected steel sheeting shall be fastened to battens, purlins or decking using galvanisedhead twisted shank nails that are at least 65 mm long or galvanised screws that are at least 50mmlong.
Where corrugated sheeting is used, the nails or screws shall be driven through the crown of thecorrugation.
The minimum fastening density of nails or screws shall be as follow
Centre of the roof minimum of 3 fixings per square meter with edge fixation of the sheet.
Roof edges eaves and ridges almost one fixing every 250mm maximum.
7.2.3.2 Metal roof panels
The installation of metal roof panels shall comply with the provisions of this section.
7.2.3.2.1 Deck requirements.
Metal roof panel roof coverings shall be applied to a solid or spaced sheathing, except where theroof covering is specifically designed to be applied to spaced supports.
7.2.3.2.2 Slope.
The minimum slope for lapped, non-soldered seam metal roofs shall be 25% (14°).
The minimum slope for standing seam roof systems shall be 2.5%.(1/40)
7.2.3.2.3 Material standards.
Metal-sheet roof covering systems that incorporate supporting structural members shall bedesigned in accordance with the code.
Metal-sheet roof coverings installed over structural decking shall comply with table.
Metal roof coverings standards and installation
Roof covering type Standard application Rate / thickness
Galvanised steel TTS 16 35 511: 1988 0.63mm thick minimum
Pre-painted steel ASTM A755
Aluminium Zinc Alloy CoatedSteel
TTS 16 35 511: 1988
Lead-coated copper ASTM B101
Copper 4.9 kg/m2
Hard lead 9.8 kg/m2
Soft lead 14.6 kg/m2
Aluminium 0.60mm minimum thickness
7.2.3.2.4 Attachment.
Metal roofing shall be installed in accordance with this chapter and the manufacturer's installationinstructions. Approved fasteners shall attach metal roofing fastened directly to steel framing. Thefollowing fasteners shall be used:
1. Galvanised fasteners shall be used for galvanised roofs.
2. Hard copper or copper allow shall be used for copper roofs.
3. Stainless steel fasteners are acceptable for metal roofs.
7.2.3.3 Asphalt singles
The installation of asphalt shingles shall comply with the provisions of this section.
7.2.3.3.1 Deck requirements.
Asphalt shingles shall be fastened to solidly sheathed decks.
7.2.3.3.2 Slope.
Asphalt shingles shall only be used on roof slopes of 17% (10°) or greater.
7.2.3.3.3 Underlay.
For roof slopes from 17% (10°), up to 35% (20°), underlay shall be two layers applied in thefollowing manner.
Apply a 480mm strip of underlay felt parallel with and starting at the eaves, fastened sufficiently tohold in place. Starting at the eaves, apply 900mm wide sheets of underlay overlapping successivesheets 480mm and fastened sufficiently to hold in place.
For roof slopes of 35% (20°) or greater, underlay shall be one layer applied in the followingmanner.
Underlay shall be applied shingle fashion, parallel to and starting from the Eva and lapped 50mmfastened sufficiently to hold in place.
End laps shall be offset by 1.80m.
Underlay applied in areas subject to high winds (greater than 145km/hr) shall be applied withcorrosion-resistant nails in accordance with manufacturer's installation instructions.
Fasteners are to be applied along the overlap not farther apart than 900mm on centre.
7.2.3.3.4 Material standards
Unless otherwise noted, required underlay shall conform to ASTM D226, Type 1, or ASTM D4869, Type 1.
Asphalt shingles shall have self-seal strips or be interlocking, and comply with ASTM D225 orD3462.
7.2.3.3.5 Fasteners.
Asphalt shingles shall be fixed to the decking using the proper adhesives in accordance with themanufacturer’s instructions. (Galvanised extra large head clout nails may also be used for fasteningasphalt shingles
Corrosion resistant nails minimum 3.5mm, 10mm head, or approved corrosion-resistant staples,minimum 2mm x 24mm crown width.
Fasteners shall be long enough to penetrate into the sheathing 20mm or through the thickness ofthe sheathing, wherever is less.
Asphalt shingles shall have the type and minimum number of fasteners required by themanufacturer. For normal application, asphalt shingles shall be secured to the roof with not less thanfour fasteners per strip shingle or two fasteners per individual shingle.
Where the roof slope exceeds 166% (60°), special methods of fastening is required.
7.2.3.3.6 Flashing.
Flashing for asphalt shingles shall comply with this section.
7.2.3.3.6.1 Base and cap flashing.
Base and cap flashing shall be installed in accordance with manufacturer's installation instructions.
Base flashing shall be of either corrosion-resistant metal of minimum nominal 0.50mm thicknessor mineral surface roll roofing weighing a minimum of 3.75kg/m2.
Cap flashing shall be corrosion resistant metal of minimum nominal 0.50mm thickness.
7.2.3.3.6.2 Valleys.
Valley linings shall be installed in accordance with manufacturer's installation instructions beforeapplying shingles.
Valley linings of the following types shall be permitted.
1. For open valley (valley lining exposed) lined with metal, the valley lining shall be at least 600mmwide and of any of the corrosion-resistant metals.
2. For open valleys, valley lining of two plies of mineral surface roll roofing, complying with ASTMD249, shall be permitted. The bottom layer shall be 450mm and the top layers a minimum of 900mmwide.
3. For closed valleys (valley covered with shingles), valley lining of one ply of smooth roll roofingcomplying with ASTM D 224 Type II or Type III and at least 900mm wide or valley lining as describedin paragraphs 1 and 2 above shall be permitted.
Speciality underlay complying with ASTM D 1970 may be used in lieu of the lining material.
Valley lining material
Material Minimum thickness Weight/m2
Copper 5 kg/m2
Aluminium 0.60 mm
Stainless steel 0.40 mm
Galvanised steel 0.63 mm
Zinc alloy 0.70 mm
Lead 12 kg/m2
7.2.3.3.7 Crickets and saddles.
A cricket or saddle shall be installed on the ridge side of any chimney greater than 750mm wide.Cricket or saddle coverings, shall be sheet metal or of same material as roof covering.
7.2.3.4 Metal roof shingles
The installation of metal roof shingles shall comply with the provisions of this section.
7.2.3.4.1 Deck requirements.
Metal roof shingles shall be applied to a solid or closely fitted deck, except where the roof coveringis specifically designed to be applied to spaced sheathing.
7.2.3.4.2 Deck slope.
Metal roof shingles shall not be installed on roof slopes below 17% (10°).
7.2.3.4.3 Underlay. .
Not required
7.2.3.4.4 Material standards.
Metal roof shingle roof coverings of galvanised steel shall be 0.40mm minimum thickness.
Metal roof shingle roof coverings of aluminium shall be of 0.60mm minimum thickness.
7.2.3.4.5 Application.
Metal roof shingles shall be secured to the roof in accordance with this chapter and the approvedmanufacturer's installation instructions.
7.2.3.4.6 Flashing.
The roof valley flashing shall be provided of not less than 0.40mm corrosion-resistant metal, whichshall extend at least 200mm from the centre line each way and shall have a splash diverter rib not lessthan 20mm high at the flow line formed as part of the flashing.
Sections of flashing shall have an end lap of not less than 100mm.
The metal valley flashing shall have a 900mm wide underlay directly under it consisting of onelayer of underlay running the full length of the valley, in addition to underlay required for metal roofshingles.
7.2.3.5 Slate shingles
The installation of slate shingles shall comply with the provisions of this section.
7.2.3.5.1 Deck requirements.
Slate shingles shall be fastened to solidly sheathed roofs.
7.2.3.5.2 Deck slope.
Slate shingles shall only be used on slopes of 50% (26°) or greater.
7.2.3.5.3 Underlay.
Not required
7.2.3.5.4 Material standards.
Slate shingles shall comply with ASTM C406.
7.2.3.5.5 Application.
Minimum head-lap for slate shingles shall be in accordance with the following table.
Slate shingles shall be secured to the roof with two fasteners per slate. Slate shingles shall beinstalled in accordance with this chapter and the manufacturer's installation instructions.
Slate single head-lap
Slope Head-lap
50% (26°) < slope < 70% (35°) 100mm
70% (35°) < slope < 166% (60°) 75 mm
Slope < 166% (60°) 50 mm
7.2.3.5.6 Flashing.
Flashing and counter-flashing shall be made with sheet metal. Valley flashing minimum of 400mmwide. Valley and flashing metal shall be a minimum uncoated thickness of 0.50mm zinc coated.
Chimneys, stucco or brick walls shall have a minimum of two plies of felt for a cap flashingconsisting of 100mm wide strip of felt set in plastic cement and extending 25mm above the first feltand a top coating of plastic cement. The felt shall extend over the base flashing 50mm.
7.2.3.6 Clay and concrete tile.
The installation of clay and concrete shall comply with the provisions of this section.
7.2.3.6.1 Deck requirements.
Concrete and clay tile shall be installed only over solid sheathing or spaced structural sheathingboards.
7.2.3.6.2 Deck slope.
Clay and concrete roof tile shall be installed on roof slopes of 25% or greater. For roof slope 25%to 35%, double underlay application is required.
7.2.3.6.3 Underlay.
Unless otherwise noted, required underlay shall conform with: ASTM D226, Type 11; ASTMD2626, Type I; or ASTM D249 mineral surfaced roll roofing.
7.2.3.6.3.1 Low slope roofs.
For roof slopes from 25% (15°), up to 35% (20°), underlay shall be a minimum of two layersunderlay applies as follows:
I. Apply a 450mm strip of underlay felt parallel with and starting at the eaves fastened sufficientlyin place. End laps shall be offset by 1.80m.
2. Starting at the Eaves, apply 900mm wide sheets of underlay felt overlapping successive sheets450mm and fastened sufficiently in place.
7.2.3.6.3.2 High slope roofs.
For roof slopes of 35% (20°), or greater, underlay shall be a minimum of one layer of underlay feltapplied shingle fashion, parallel to, and starting from the eaves and lapped 50mm, fastened sufficientlyin place.
7.2.3.6.3.3 Underlay and high wind.
Underlay applied in areas subject to high wind (greater than 145 km/h) shall be applied withcorrosion-resistant nails in accordance with manufacturer's installation instructions. Fasteners are tobe applied along the overlap not farther apart then 900mm on centre.
7.2.3.6.4 Tile standards.
Clay roof tile shall comply with ASTM C 1167
Concrete roof tile shall comply with BS EN 490 Concrete roofing tile and fittings
7.2.3.6.5 Fasteners.
Nails shall be corrosion-resistant and not less than 3.5mm, 8mm head, and of sufficient length topenetrate the deck a minimum of 20mm or through the thickness of the deck, whichever is less.Attaching wire for clay or concrete tile shall not be smaller than 2.00mm. Perimeter fastening areasinclude three tile courses but not less than 900mm from either side of hips or ridges and edges ofeaves and gable rakes.
Clay and concrete tile attachment
Sheathing Roof slope Number of fasteners
Solid without battens All One per tile
Spaced or solid with battens Slope < 40% (22°) Not required
40% (22°)< slope <100%(45°)
One per tile/every other rowSpaced sheathing withoutbattens
100% (45°)< slope < 200%(64°)
One per tile
7.2.3.6.6 Application.
Tile shall be applied in accordance with this chapter and the manufacturer's installationinstructions, based on the following:
1. Roof Slope
2. Underlay system
3. Type of tile being installed
Clay and concrete roof tiles shall be fastened in accordance with this section and themanufacturer's installation instructions. Perimeter tiles shall be fastened with a minimum of onefastener per tile. Tiles with installed weight less than 45kg/m2 require a minimum of one fastener pertile regardless of roof slope. Clay and concrete roof tile attachment shall be in accordance with themanufacturer's installation instructions where applied in areas where the winds speed exceeds130km/hr and on buildings where the roof is located more than 12m above grade. In all other areas,clay and concrete roof tiles shall be attached.
7.2.3.6.7 Flashing.
At the juncture of the roof vertical surfaces, flashing and counter flashing shall be provided inaccordance with this chapter and the manufacturer's installation instructions, and where of metal, shallnot be less than 0.50mm corrosion resistant metal.
The valley flashing shall extend at least 300mm from the centreline each way and have a splashdiverter rib not less than 25mm high at the flow line formed as part of the flashing.
Sections of flashing shall have an end lap of not less than 100mm.
For roof slopes of 25% (15°) and over, the valley flashing shall have a 900mm wide underlay ofone layer of Type I underlay running the full length of the valley, in addition to other required underlay.
7.2.3.7 Built-up roofs.
The installation of built-up roofs shall comply with the provisions of this section.
7.2.3.7.1 Slope.
Built-up roofs shall have a design slope of a minimum of 2.5% for drainage, except for coal-tarbuilt-up roofs that shall have a design slope of a minimum 1%.
7.2.3.7.2 Material standards.
Built-up roof covering materials shall comply with the standards in table.
BUILT-UP ROOFING MATERIAL STANDARDS
MATERIAL STANDARD STANDARD
Aggregate surfacing ASTM D1863
Asphalt-coated glass fibber base sheet ASTM D4601
Asphalt glass felt ASTM D2178
Asphalt-saturated and asphalt-coated organic felt base sheet ASTM D2626
Asphalt-saturated organic felt (perforated) ASTM D226
Asphalt used in roofing ASTM D312
Coal-tar saturated organic felt ASTM D227
Coal-tar used in roofing ASTM D450, Types I orII
Glass mat, coal tar ASTM D4990
Glass mat, venting type ASTM D4897
Mineral-surfaced inorganic cap sheet ASTM D3909
7.2.3.7.3 Application.
Built-up roofs shall be installed according to this chapter and the manufacturer's installationinstructions.
8 FiguresIn AutoCAD 14
Principle
Fig A1-1 Plan of building proportion X
Fig A1-2 Recommended location of wall openings X
Fig A1-3 Recommended location of wall opening for two storey building X
Fig A1-4 Typical roof gable wall arrangement X
Fig A1-5 Recommended method of construction on sloping sites X
Fig A1-6 In-fill panel between timber building supports X
Fig A1-7 Timber framing showing bracing X
Fig A1-8 Timber framing for wall X
Fig A1-9 Rafter/wall plate connections X
Fig A1-10 Rafter/ring beam connections X
Fig A1-11 Wall plate connections and hurricane ties X
Design criteria
Fig A2-1a Basic 1 or 2 level house type X
Fig A2-1b Mixed 1 or 2 level house type X
Fig A2-1c 1 or 2 level house, other type of combination X
Fig A2-2 Trinidad & Tobago Winds X
Fig A2-3 Trinidad flood prone areas X
Fig A2-4 Tobago flood prone areas Not available
Minimal requirement
Fig A3-1 Minimum room sizes X
Fig A3-2 Typical furniture arrangement X
Fig A3-3 Typical furniture arrangement, 7.5m2 room X
Fig A3-4 Habitable room area X
Fig A3-5 Toilet, bath and shower space required X
Fig A3-6 Stairs and landings X
Fig A3-7 Ramps and landings X
Fig A3-8 Steps (Treads, risers and nosing) X
Fig A3-9 Stair handrails X
Fig A3-10 Guards X
Fig A3-11 Septic tank 2500 litres 5 persons maxi X
Fig A3-12 Septic tank 3200 litres 8 persons maxi X
Fig A3-13 Soak-away X
Fig A3-14 Draining trench X
Foundations
Fig B-1 Foundation types X
Fig B-2-1a Arrangement for strip footing 150mm vertical core blocks X
Fig B-2-1b Arrangement for strip footing 200mm vertical core blocks X
Fig B3 Typical spread footing details X
Masonry
Fig B-4 1 and 2 level House type X
Fig B-5 Load & non load bearing clay or concrete blocks X
Fig B-6-1 Shear panel - Vertical core blocks X
Fig B-6-2 Shear panel - Horizontal core blocks X
Fig B-7-1 Typical external wall arrangement X
Fig B-7-2 Typical external wall arrangement X
Fig B-8 Openings and lintels X
Fig B-9-1 Typical wall corner details - Vertical core blocks X
Fig B-9-2 Typical wall corner details - Horizontal core blocks X
Fig B-10-1 Typical wall intersection details- Vertical core blocks X
Fig B-10-2 Typical wall intersection details- Horizontal core blocks X
Fig B-11-1 Typical wall reinforcement and phasing construction-Verticalcore
X
Fig B-11-2 Typical wall reinforcement and phasing construction- horizontalcore
X
Fig B-12-1 Internal wall arrangement and reinforcement-vertical core X
Fig B-12-2 Internal wall arrangement and reinforcement-horizontal core X
Fig B-13 Ring beam reinforcement X
Fig B-14 Detail of ground floor slab on grade X
Fig B-15 Detail of suspended ground floor slab X
Fig B-16 Typical hip roof construction X
Fig B-17-1 2 level house - Typical cross section masonry blocks X
Fig B-17-2 2 Level house - Typical cross section columns, beams andshear panel
X
Fig B-17-3 2 Level house - Typical cross section framed structure Next edition
Fig B-18 Slabs and beams typical arrangements X
Fig B-19-1 Beam reinforcement - Typical arrangement Mild Steel X
Fig B-19-2 Beam reinforcement - Typical arrangement HR steel X
Fig B-20 Concrete beams (Middle and Side) X
Fig B-21 Beam sections X
Timber
Fig C-1 Wall height X
Fig C- 2 Top plate framing to accommodate piping X
Fig C -3 Typical wall, floor and roof framing X
Fig C- 4 Framing details X
Fig C- 5 Floor construction X
Fig C- 6 Joist cutting, notching and drilling X
Metal steel X
Fig D1-1 Steel frame typical X
Fig D1-2 Z purlin details X
Fig D1-3 Beam framing X
Fig D1-4 Column base plates X
Fig D1-5 Roof beam details X
Fig D1-6 Z or C steel profile used as rafter X
9 Tables
Tables not in the Word text.
Concrete
Table B-1 Concrete composition X
Table B-4 Typical reinforcement for two way slabs X
Table B-7-1 Typical reinforcement for concrete beams-
2 way slab and MS Steel grade 250
X
Table B-7-2 Typical reinforcement for concrete beams-
1 way slab and MS Steel grade 250
Next edition
Table B-7-3 Typical reinforcement for concrete beams-
2 way slab and HR Steel grade 420
X
Table B-7-4 Typical reinforcement for concrete beams-
1 way slab and HR Steel grade 420
Next edition
Timber
Table C-1 Timber names for use in Trinidad & Tobago X (2 pages)
Table C-5 Maximum roof span for rafter X
Table C-6 Maximum roof span for battens and joists X
Steel structure
Table D-1 Z purlins X
Table D-2 MS beam type 1 X
Table D-3 MS beam type 2 X
Table D-4 Z or C rafters X
10 Normative references
This chapter lists the standards that are referenced in various sections of thisdocument.
ASTMAmerican Society for Testing and Materials
100 Barr Harbor Drive
West Conshohocken, PA 19428
Standard referencenumber
Title Code reference
ASTM A 755M - 94 Specification for steel sheet, metalliccoated by the hot dip process and pre-paintedby the coil-coating process for exterior exposedbuilding products
Roof materials
ASTM B 101-96 Lead coated copper sheets Roof materials
ASTM C 34-96 Specification for structural clay load-bearing wall tile.
Hollow masonry blocks
ASTM C 406 - 89 Specification for roofing slate Roof materials
ASTM C 652-95a Specification for hollow brick (Hollowmasonry units made from clay or shale)
Hollow masonry blocks
ASTM C 1167 -94a
Specification for clay roof tiles Roof materials
ASTM D 224 - 89 Specification for smooth surfaced asphaltroll roofing (Organic felt)
Roof materials
ASTM D 225-95 Asphalt shingles (Organic felt) surfacedwith mineral granules
Roof materials
ASTM D 226-94 Specification for asphalt-saturated organicfelt used in roofing and water proofing
Roof materials
ASTM D 227-97a Coal tar saturated organic felt used inroofing and waterproofing
Roof materials
ASTM D 249-89(96)
Specification for coal tar saturated organicfelt used in roofing and water proofing
Roof materials
ASTM D 312-84 Specification for asphalt used in roofing Roof materials
ASTM D 450-96 Coal tar pitch used in roofing, damp-proofing and waterproofing
Roof materials
ASTM D 1863-93(96)
Mineral aggregate used in built up roofs Roof materials
ASTM D 2178-97a Asphalt glass felt used in roofing andwaterproofing
Roof materials
ASTM D 2626-97a Asphalt saturated and coated organic feltbase sheet used in roofing
Roof materials
ASTM D 3462-97a Asphalt shingles made from glass felt andsurfaced with mineral granules
Roof materials
ASTM D 3909-97a Asphalt roll roofing (Glass felt) surfacedwith mineral granules
Roof materials
ASTM D 4601-97a Asphalt coated glass fibre base sheet usedin roofing
Roof materials
ASTM D 4869-88 Asphalt saturated organic felt underlayused in roofing
Roof materials
ASTM D 4897-97a Asphalt coated glass fibre venting basesheet used in roofing
Roof materials
ASTM D 4990-97a Coal tar glass felt used in roofing andwaterproofing
Roof materials
ASTM E 84-91a Test method for surface burningcharacteristics for building materials
Foam plastic
Flame spread andsmoke density
Insulation
ASTM E 90-90 Test method for laboratory measurementof airborne sound transmission loss of buildingpartitions
Dwelling unit separation
ASTM E 96-92 Standard test methods for water vapourtransmission of materials
Moisture vapourretarders
ASTM E 119-88 Test methods for fire tests of buildingconstruction and materials
Dwelling unit separation
ASTM E 492-90(96)
Test method for laboratory measurementof impact sound transmission through floorceiling assemblies using the tapping machine
Dwelling unit separation
ASTM E 814-94b Test method for fire tests of throughpenetration fire stops
Dwelling unit separation
ASTM E 970-94a Standard test method for critical radiantflux of exposed attic floor insulation using aradiant heat energy source
Insulation
ASTM E 1300-97 Standard practice for determining theminimum thickness and type of glass requiredto resist a specified load
Glazing
AWPAAmerican Wood-Preservers Association
PO Box 5690
Granbury, Texas 76049
Standard referencenumber
Title Code reference
C1-90 All timber products- Preservativetreatment by pressure processes
Protection against termites
C15-90 Wood for commercial-residentialconstruction- Preservative treatmentby pressure processes
BSBritish Standards
Standard referencenumber
Title Code reference
BS EN 490 : 1994 Concrete roofing tiles and fittings.Product specifications.
Roof materials
CPSCConsumer Product Safety Commission
4330 East West Highway
Bethesda, MD 20814-4408
Standard referencenumber
Title Code reference
CPSC 16-CFR,part 1201-77
Safety standard for architecturalglazing
Glazing
CPSC 16-CFR part1209-79
Interim safety standard forcellulose insulation
Insulation
CPSC 16-CFR part1404
Cellulose insulation Insulation
CUBIC
Standard referencenumber
Title Code reference
IRCInternational Residential Code for One and Two Family Dwellings
Doubletree Hotel
3050 Bristol Street
Costa Mesa, CA 92626
Standard referencenumber
Title Code reference
ISOCase postale 56
CH- 1211 Geneva, 20
Switzerland
Standard referencenumber
Title Code reference
STD Version 1 STD template for the preparationof normative-type documents.
Reference manual.
Presentation of the "Smallbuilding code".
TTSTrinidad and Tobago Standard
Trincity Industrial Estate
Macoya, Tunapuna, Trinidad
Standard referencenumber
Title Code reference
TTS 16 80 400:1991
Code of practice for the designand construction of septic tanks andassociated secondary treatment anddisposal system.
Sanitation
TTS 16 35 508 Specification for load bearingmasonry concrete units.
Hollow masonry blocks
TTS 16 35 509 Specification for non load bearingconcrete masonry units.
Hollow masonry blocks
TTS 16 35 511:1998
Specification for corrugatedgalvanised and aluzinc coated steelsheets for roofing and generalpurpose.
Roof materials
TTS 26 20 505 Electrical code Dwelling unit separation
TTS 583:2000 Carbon steel bars for thereinforcement of concrete -Specification
Basic materials
ULCUnderwriters Laboratories of Canada
7 Crouse Road
Scarborough, Ontario, Canada MIR 3A9
Standardreference number
Title Code reference
S102.2 - M88 Standard method of test forsurface burning characteristics offlooring, floor covering andmiscellaneous materials and assembly
Insulation