pricing preambles

PRICING PREAMBLES

1. GENERAL

a. The Contractor shall fully read and be conversant with full description of workmanship and materials as described in the specification of works for respective items, prior to the preparation of tender.

b. All quantities are measured generally in accordance with The Method of Measurement of Building Works - Sri Lanka Standard 573: 1982 UDC 69 (083-74). In the absence of a method in aforesaid method of measurement, the Standard Method of Measurement in Building Works in Sri Lanka - Building Department shall apply. If any other deviation is made to measure the quantities for any items of works, it is reflected in the relevant item of work or stated in the relevant trade preamble hereof.

c. The rate for each item must be comprehensive and must include for complying in all respects with the requirements of the specification, the pricing preambles, cover all the obligations under the contract, and all matter and things necessary for the proper construction completion and maintenance of works. No claim for additional payment will be allowed for any error or misunderstanding by the Contractor of the work involved.

d. The Contractor must obtain all detailed information from the relevant authorities as to the existence of service lines (underground and overhead), such as power cables, drainage lines, water pipes, and the like, and should check as to whether they are to be protected, altered, or removed, and to do the necessary as the case may be. If it is to be altered or diverted as directed by the Employer as a part of design requirement, the cost in connection with such works shall be paid to the Contractor by Employer on a mutually agreed basis, provided such works are not separately measured, or not included in the cost of other items of work, and/or not covered by the preamble notes under relevant trade/ section.

e. The rates of each item shall include for :i. Labour and all costs in connection.ii. Materials and goods including all costs in connection.iii. Samples to be given for approval.iv. Setting out of works and preparatory works.v. Complying with regulations of urban councils or municipal councils and/or any other relevant

authorities under whose permission the particular item of work shall be executed.vi. Fitting and fixing materials and goods in position including hoisting to any height or lowering to

any depth and all temporary works, including loading, transporting, unloading, and storing.vii. Square cutting, waste materials, testing, and furnishing of test certificates.viii. Preliminaries unless otherwise separately priced.ix. Protecting and cleaning works during construction and on completion.x. Establishment charges, overheads, and profits

f. Where the word "allow" occurs the costs of items shall be at the risk of the Contractor.

g. The Contractor is to refer preamble notes of the relevant trade for any item of work, or which has been described together with any other item of works under a different trade, during pricing.

h. The word "fix only" used hereinafter in connection with goods or materials supplied by Employer, Nominated Suppliers, or others, shall be deemed to include, on the part of the Contractor taking delivery, loading and transporting to site, unloading, stacking or storing under cover if damage could occur by exposure to weather, taking from store and distributing to job, handling, and hoisting. Contractor must allow for the full cost of replacement of items which are damaged, broken, lost, or

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SpecificationsEXCAVATION AND EARTHWORK PLUMBING

CONCRETE WORK DRAINAGE WORK

MASONRY CARPENTRY

WALL, FLOOR, AND CEILING FINISHES JOINERY

PAINTING IRON MONGERY

stolen, after accepting delivery.

i. The system allowed in numbering the trade in this pricing preamble is as per same sequence in Method of Measurement of Building Works Sri Lanka Standard 573-1982- UDC 69(083-74).

j. A separate item is provided in the BOQ for the construction of temporary bus shelters and the covered fence, temporary gates in front only.

k. For the Construction of the kerbs the tenderer must allow in his rates, for any excavation of the hard shoulder constructed for temporary bus stops and any abortive work to install permanent features

2. EXCAVATION AND EARTHWORK

a. Exiting ground level indicated as +/- in drawings shall be the level of trimmed ground free of all structures, pavings, plinths, foundations, and the like.

b. The Contractor is advised to inspect the Soil Investigation Report which is available with the Employer in order to determine the type of soil generally encountered.

c. The Contractor is required to inspect the site in order to acquaint himself with the condition of site and the subsoil, prior to preparing his tender.

d. Surplus excavated materials not suitable for filling shall be removed at the expense of the Contractor.

e. The Contractor must obtain all detailed information from the relevant authorities in compliance with relevant acts, by-laws, and regulations, on excavations, planking, and strutting.

f. The Contractor shall submit samples and obtain test certificates as required by the contract documents.

g. The rate for compacted earth fill and granular fill, stone, gravel, and sand beds, shall include for imported materials or materials from borrow areas. If any excavated materials arising from construction works are used an adjustment will be made in the Final Account on the rates of applicable materials.

h. Planking and strutting measured shall include additional width of excavation as required by the Standard Method of Measurement if measured separately.

i. Rates for Excavation and Earthwork shall include for-

i. Excavating by whatever means are necessary including excavation by manually or by machinery, in any type of ground including boulderised ground but except in rock.

ii. Trimming sides, keeping clean and consolidating bottom of bases and trenches unless measured separately.

iii. ack filling and disposal of surplus excavated materials as specified and directed.iv. Any necessary additional excavation for working space, planking and strutting, form work etc.

j. Rates for all excavation works shall include for dewatering works, using pumps, if the need arises due to ground water condition or rain.Planking and Strutting

Note :

a. Payment for planking and strutting will only be considered on actual quantitiesof work executed.

b. Planking and strutting shall be carried out only if specifically instructed to do so by the Employer.

v. Any additional trimming or appropriate back filling to provide the specified or approved formation

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and profile, necessitated by the uneven excavation of earth, unless measured separately

k. Rate for compacted earth fill and granular fill and gravel and sand beds shall include for grading to slopes and falls, depositing in layers, levelling, blinding, machine or hand packing to form vertical or battered or level faces, and for forming sinking required under floor slabs or sub-floor layers.

l. Rate for Damp Proof Membrane or polythene sheeting are to include for laps and straight, raking and circular cutting, and for notching around all obstructions.

3. CONCRETE WORK

a. Testing-All concrete shall be tested in accordance with specification clauses and the Contractor shall allow for all costs and charges involved in sampling and testing. He shall maintain on site in good order and condition, all equipment necessary for taking of slump and compression test specimens. Laboratory tests shall be carried out by an organization acceptable to the Employer and the Contractor shall be responsible for making arrangements to submit test samples to the testing organization and obtain reports and submit same to the Employer.

b. Ready Mixed Concrete-Ready mixed concrete manufactured and delivered to the site by an organization of repute acceptable to the Employer will be permitted. The Contractor shall give all details such as place of purchase, time in transport, admixtures, etc and obtain prior approval of the Employer before orders are placed.

c. Curing-All concrete surfaces shall be effectively protected from rain until a hard set has occurred. All necessary materials for the protection and curing shall be on the site, before any mixing or delivery of concrete to the site.

d. Surface finish-The Contractor shall provide formwork appropriate to the required formed finish and to the dimensional tolerance given by the Employer.

All concrete surfaces not exposed in the finished work, including substructure and concrete surfaces to be subsequently plastered, shall be of "Basic Formed Finish" as mentioned in the clause specifications. All other concrete surfaces that will not be plastered but will be painted shall have a "Plain Formed Finish" as mentioned in the clause specifications.

e. Concrete surfaces in areas specified by the Employer that will remain unplastered and unpainted, shall have a "Fine Formed Finish" as mentioned in the clause specifications.

f. Rates for concrete work shall include for :i. Mixing, deposition, handling, and hoisting into position.ii. Packing and tamping around reinforcement including vibrating.iii. Finishing to slopes and falls and prepare surface ready for screeds or paving

where necessary.iv. All necessary expansion joints or sealers including cutting to sizes and

temporary supports, required to form necessary grooves, if not measured separately.

v. Curing as specified and stop pour construction joints etc.

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vi. Cutting or forming chases, rebates, and grooves, forming holes and subsequently making good around pipes, sleeves, conduits, ducting metal sections and fittings and for forming all holes or openings.

vii. All necessary shuttering to edges of blinding concrete

g. Rate for reinforcements shall include for straightening as necessary, cutting to length, bending as required, hoisting to any height and fixing in foundations, columns, beams, slabs, stair cases, and any other position, cleaning, etc., and supporting in position during concreting including all necessary supports, except special chairs and spacer bars, including stirrups and links, steel binding wire and approved distance pieces.

h. Rates for formwork shall include for:i. General formwork, working in narrow widths and small quantities, for setting

up, strutting and supporting at any height, together with any necessary strutting and supporting through lower floors, coating with form releaser, easing, striking and removing, cleaning, preparing for reuse, and removal when no longer required, including all props, stays, struts, wedges and bolts, all overlaps and passing at angles and labours at intersections, rubbing and making good the surface of the concrete after removal of the shuttering.

ii. All fillets to form grooves, rebates, and throats, splays or chamfers, raking, circular cutting, cutting around all pipes, sleeves, conduits, ducting metal and sections, and fittings.

iii. Providing samples as required by the Employer of different formed finishes specified.

NOTE :- No payment shall be made when face of bricks, concrete, and rubble, etc. are used as formwork.

4. MASONRY

a. Rates for brickwork and block work shall include for:

i. Plumbing angles, straight cutting forming rebated reveals, and raking out joints for plastering.

ii. Splay cutting, rough cutting, fair cutting, forming chases or grooves for slabs, partitions, staircases roofs and the like, and bonding end of walls.

iii. Building at any level or height of slabs or beams, additional labour in curbs, isolated and attached piers, all cutting, bonding at angles and intersections, building into or against adjacent work, wedging and pinning upto soffits.

iv. Fixing metal, clamps, ties, etc.v. Necessary cutting required in walls which are not multiples of brick size.vi. Preparing existing walls for raising and pinning new brickwork.vii. Bonding new walls to old walls where necessary and materials used.viii. Any extra scaffolding required for working in double height areas.

b. Rates for brick facing shall include for the following in addition to above.

i. Plumbing angles, straight cutting and protecting finished surfaces.ii. Fair, raking, splay, or circular cutting.iii. Chamfered, rounded, or moulded angles.

c. Rates for Damp Proof Course shall include for:

i. Necessary levelling and trimming top of rubble/block/brick -plinth wall.ii. Fair edges, rounded edges, drips and arises, angle fillets.iii. Turning ribs of asphalt into grooves.

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iv. Cutting, line, and jointing new to old asphalt.

d. Rates for rubble masonry shall include for:

i. All joggles, cramps, dowels, ties, and templates.ii. Plumbing angles, fair returns setting, jointing, eaves filling, pointing and fixing

in position, complete, and hoisting to any given height.iii. Bond end of walls, rough cutting, and fair cutting.iv. Levelling up in walling for damp proof courses, sills, thresholds, string course,

coping and the like.v. Forming straight vertical joints next to dressings, panels, brickwork etc.vi. Forming opening and dressed margin.vii. Forming chases, throats, rebates, margin flutes, sinking, chamfered and

rounded edges, and all labour connected therewit

5. WALL, FLOOR, AND CEILING FINISHES

Rate for Wall, Floor, and ceiling finishes shall include for:

i. All temporary rules, screeds, templates, and supports, curing and cleaning off on completion, and exact

ii. thickness required to finish.

iii. Working at any given height.

iv. Work in small quantities/ panels/ narrow width/ angles ends/ short length.

v. Making good or cutting around bolts, pipes, conduits, sleeves, ducting, fittings, sections, and the like obstructions.

vi. Raking out joints of new brickwork/blockwork, or hacking new concrete to form key including brushing, cleaning, dampening the background.

vii. Forming internal and external angles and arises.

viii. Any extra thickness required to finish the true level.

6. PAINTING

a. Rate for painting shall include for-

i. Preparation of surfaces, cleaning, and smoothening, by sand paper or glass etc.Where smoothening or evenness cannot be obtained due to uneven plastering, the contractor shall apply masonry filler repeatedly at his cost to obtain an even surface.

ii. Protection of floor, walls, and fittings, etc.iii. Working at any height, working to returns, pointing in any colour, multi-colour

work if any, and painting in small quantities.iv. Cleaning on completion.

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b. The rates for work to isolated general surfaces shall include for working on door frames, linings, window subframes (if different from window), skirting, rails, architraves, bars, posts, balusters, and the like.

c. Rates for glazed general surfaces, glazed windows and the like (measured flat over glass irrespective of size of pane), shall include for work to edges and glazing rebates, returns and mouldings of frames, mullions, transoms, architraves, and the like.

d. The rates to work to pipes and conduit, (including trunking, ducting, and the like), shall include for all work on hangers, supports, brackets, and the like.

7. PLUMBING

a. The Scope of Work covers external and internal plumbing.

b. All works shall conform to the requirements of Statutory Authorities, such as Municipal Councils, Urban Councils, and where applicable their certificates shall be produced to the Employer as evidence of satisfactory proof.

c. The provisions of clauses of preceding trades and following trades shall apply equally to relevant item given under this trade.

(a) Wall and Ceiling finishes.(b) Painting.

d.i. All Unplasticized Polyvinyl Chloride (UPVC) pipes used in the plumbing

installations must conform in every respect to the requirements of the SLS 147 of 1982 and 1972 or BS 4514, or to other, international standards for which written approval has been given by the employer.

ii. All fittings and specials used in the plumbing installations shall be molded and suitable in all respects to the pipe line to which these fittings and specials are fixed. Fabricated fittings and specials shall not be used.

iii. Where pipes pass through walls or slabs, pipes shall be wrapped in a layer of inert materials; and for pipes exceeding 50mm dia. sleeve pipes shall be used for the full thickness.

iv. All plumbing ancillaries, such as taps, valves, cocks, and floor waste covers shall be of Brass, Chromium plated Brass (C.P. Brass), or Stainless Steel, unless otherwise stated.

v. Fittings for pipes less than 4" (110mm) dia. are said to be included in the rates, and fittings for pipes 110mm dia. or above, will be separately measured.

vi. The Contractor shall make all payments necessary to Local Authority and obtain water supply and drainage connections.

vii. The given diameter of each pipe shall be the nominal internal bore.viii. All items shall be paid on a measure and pay basis, calculated at the rates

mentioned in the Tender.

e. The rates for plumbing shall include,i. Screws, nails, sockets, connectors, backnuts, nipples, standard pipe fixing or

supporting clips, saddles, brackets, straps, solder rivets, connectors, flanges pipe sleeves, and the like.

ii. Short lengths, joints, connections, and couplers in running length.iii. Sealing, fixing and support with holder bats or pipe clips cut and pinned built

in wall or slabs.iv. Plugging and screwing to walls or ceiling.v. All laps, straight cuttings, and waste.vi. Fittings including bends, tees, collars, reducers, elbows, valve sockets,

junctions, caps, and the like, for pipes less than 110mm dia.vii. Jointing compound, solvent cement, incidental material, and Labour.

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viii. Connecting pipes to sanitary fixtures and appliances.ix. Standard and special pipe fixing arrangements where necessary.x. All builders works such as chasing and forming holes through brickwork/

blockwork/ foundations, and concrete slabs, beams, columns, manholes, and the like, and making good all damages.

xi. Painting of all such exposed surfaces.xii. Testing and disinfection after completion.xiii. Preliminaries, unless separately measured as Items in Bills of Quantities

prepared by employer.xiv. Electrical wiring work for automatic operation of water pumps, float switches,

and starters.xv. All taxes, levies, duty including BTT, and Contractor's overheads and profits

f. Rates for valves, fittings, and ancillaries, shall include for,i. Additional supports, union couplings, flanges etc.ii. Jointing compounds, gaskets, tape, cutting and waste of pipes and jointing.iii. Jointing and or connecting pipes to ancillaries etc.

g. Rates for Sanitary fittings shall include for,

1. Fittings such as taps, waste water outlet, flushing cistern, internal overflows, and the like, and supporting brackets and incidental materials for fixing.

2. Assembling, jointing together, fixing component parts, and jointing to pipes, including necessary coupling, and leaving perfectly clean, undamaged, and in perfect working order on completion.

3. Jointing and or connecting pipes to sanitary fittings.

h. The Contract Drawings are generally diagrammatic and indicative of work to be done, and the arrangements of piping manholes, etc. shall be subject to slight modifications at site to avoid interference with the work of other trades.

i. If the Contractor wishes to deviate from Drawings for the convenient installation of the system, such changes shall require the prior written approval of the employer before execution of the works.

j. Tender's attention is drawn to the presence of a large stormwater drain running across the site. (approx. size 5' x 2'). There is a straddle foundation proposed for the building at places where the foundations meets the drain. This work is described separately in the BOQ for pricing.

k. It would be the contractor's responsibility to work within the site constraints and therefore no extra claims or requests for time extensions whatsoever will be entertained, due to the presence of this drain or any other services.

8. DRAINAGE WORK

a. The provision and clauses of preceding trades shall equally apply to relevant item of this trade.

b. Rates for trench excavation for pipes shall include for deepening and widening the trench as necessary to enable the barrels of pipes to rest on firm ground and to facilitate jointing.

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c. Rates for rock excavation in trench excavations shall include for importing selected materials to replace any excavated rock which is unsuitable for back filling and for all additional rock excavation and appropriate filling beyond the maximum measurable in accordance with the specification.

d. Rates for concrete beds and surrounds to pipes shall include for flexible joints and any necessary formwork where required by the specification.

9. WATER SUPPLY, SEWER AND DRAINAGE SYSTEMS

A. General Notes -Extent of Work

A1 The extent of the work as provided for in this bill of quantities shall consist of all the items covered under item 2 of the Specifications. (Note)

A2 Rates for all items shall be inclusive of the following :a. Provisions of holes, chases .... etc.b. All necessary scaffoldingsc. Contractor's overheads & profitsd. Providing of samples, tests, specimens ... etc. for such items of work as

required.e. All tax, levy or duty including BTT. (Note)

Water and ElectricityA3 It should bet he responsibility of the Contractor to ensure a continuous supply of

water and electricity through the construction for the works, and obtaining necessary main connections prior to the date of completion.

B. General Preamble NotesB1 ExcavatorB1.1 Rates shall include for :

a. Levelling bottom of trenchesb. Backfilling with selected excavated material and consolidating.c. Dewatering as necessaryd. Planking and strutting if requirede. Working space as required. (Note)

B2 Contractor, Formwork, reinforcement and Masonry WorkB2.1 All the "Preamble Notes" given under similar headings elsewhere in this BOQ are applicable for this section also. (Note)

B3 Roof PlumberB3.1 Rates for gutters & down pipes shall include for bends, sockets, solders, rivets,

screws, clips, straps ... etc. for all vertical & horizontal runs and labour for hoisting and fixing. (Note)

B4 Plumbing and Drainage WorkB4.1 Rate shall include for al screws, nails, clips, saddles, brackets, thrust blocks or any

such accessories required for the installation. (Note)B4.2 Rate for piping shall include for all the bends, tees, cleaning eyes, reducers,

junctions etc. and for testing of each length of piping. (Note)B4.3 Rates for pipes laid underground shall include for necessary excavation to required

gradient 1:3:6 (20 mm) mix concrete bedding, sand filling upto 300 mm above the crown of pipe, 50 mm protective cover slabs, backfilling and disposal of surplus excavated material. (Note)

B4.4 All the down runs and piping laid underground shall be of type 400/600 as directed. (Note)

B4.5 All the work shall conform to the requirements of the relevant local Authorities. (Note)

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Sanitary FittingsB4.6 Rate for wash basins, bidets, closets & bath tubs shall include for chromium plated

taps, traps and flexible connections and stop cocks as required. (Note)B4.7 Rates for sanitary fitting shall also include for back boards, brass screws, supporting

brackets and fixing material as required. (Note)B4.8 Glazed ware provided under this contract shall be new, without defects and of best

quality, type and manufacture to the entire satisfaction of the Employers. As a standard of quality the contractor shall select from either "Twyford"/Ideal Standard" or an equivalent make. (Note)

B4.9 All the showers, mixers, taps etc used in sanitary fittings shall be of "GROHE" or an equivalent make. (Note)

B4.10 All the valves used under this Contract shall be of "PEGLER" or an equivalent Standardand English Made.

B4.11 Rate for tiling work shall include all costs incurred by contractor in laying the tiles asnoted in the BOQ.

Rate shall also include,

(a) All materials including cement motar bed / plaster.(b) Cost of tiles and ancillary materials.(c) Standard grouting.(d) Cover tiles in corners and edges or formation of corner by grounding.(e) Cleaning prior to handing over.

Attention of contractors are drawn to the need to produced good workmanship in tiling as per the standard practice. Colours of tiles - grouting will be specified by Employer.

PumpsB4.12 All the pumps used under this Contract shall be of "CENTRIC" or an equivalent

make. (Note)

10. CARPENTRY

a. All timber shall be measured as the nett length, unless otherwise stated and all sizes given are finishing sizes.

b. A.B. All timber shall be well seasoned and treated against termite attack before fixing in position.

c. Rates for carpentry shall include for

i. Any type of cutting required sewing, notching, drilling, trimming framing jointing, splayed edges and the like hoisting and fixing in position completed with nails, spikes, plugs screws, and glueing and priming to joints and ends.

ii. Forming splayed edge, grooves, champers, scribed and rounded edge, bevelling moulding and the like.

iii. Plugging, wedging, nuts and washers with bolts, spokets ad pins and the like.iv. Rebating, sinkings, grooving, morticingv. Additional timber length required for carpentry jointing particularly in the

timber length exceed 5m.

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d. Protection and keeping cleaning for staining polishing or painting.(g) Nogging or solid bridging cut between studs or joints for structural timber in addition to above clause.

e. In case of roof trusses rolls, drips and fillets, required in additions to above clauses.

f. In case of floor and roof decking, the rate shall include for machine sanding protecting and prepare surface to receive floor paint in addition to clauses (a) to (g) or C above.

g. In case of walls and ceiling lining, the rates shall include for jointing and fixing to walls / ceiling / eaves etc. All cover and joint strips in addition to clause (a) to (g) of C above.

h. In case of corrugated asbestos wall lining the rates shall include for cove mouldings, sills stiles and head mouldings, to opening as relevant.

i. In case of felts and insulation, no deduction have been made for area of joints, struts, rafters etc and rate shall include for laps batten fixing and laps.

j. In case of Gutter boarding the rate shall include for outlet, and the like

11. JOINERY

A. All timber shall be measured as the nett length, unless otherwise stated and all sizes given are finishing sizes.

B. All timber shall be well seasoned and treated against termite attack before fixing.

C. All timber for joinery works shall be free of sap wood defects and void of imperfections such as knots etc.

D. Timber used for joinery works except for doors and windows, fanlight and treliss work shall be well seasoned well treated, well planed class I timber unless otherwise specified.

E. Timber used for Door, window fanlight, trelliswork, louvers shall be of well treated, well seasoned, well planed, special class timber unless otherwise specified.

F. All dimensions of planks, joists, floor boards runners sash, frame beading etc. are finished sizes.

G. All doors and windows fanlight, trelliswork louvers are strictly to the drawings.

H. All frames of doors, windows, fanlight, trelliswork, louvers shall be twice rebated for plaster and shall be fixed to brick walls with 1/8" x 2" x 9" (3mm x 50 mm x 225mm) girth mild steel holdfasts.

I. Glazing used for Doors, Windows fanlight, louvers shall be void of imperfections.

J. Rates for Joinery shall include for :

1. Any type of cutting required, sewing, making notching, drilling, trimming, planing forming and jointing and the like fixing in position complete with nails, spikes plugs screws and glueing and priming to joints and ends.

2. Forming splayed and tounged edges, rebates mortices grooves, champers, scribed and rounded edge, bevelling moulding, margin and the like and rounded corners, sinkings.

3. Working to states sizes, for all short lengths making mitres, joints and ends.4. Necessary bolts, metal clips, anchors, grips and fixing joinery5. Glueing, dowelling, plugging, wedging on a pin and the like.

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6. Punching heads and filling with approved filler if nails or pins are used for fixing.

7. Counter sunking and palleting if brass screws are used for fixing.8. Painting rebates of frames before fixing glass.9. Bedding in cement mortar filling and hanging to frame lining.10. Protection and keeping clearing for staining polishing or painting.

12. IRON MONGERY

A. The Contractor to provide master keying of locks at the handing over / practical completion to the Employer.

B. The rates shall for Iron Mongery shall include for :

a. All cutting, fitting, sinking, boring and morticing.

b. Removing during decoration, leaving oiled and in proper working order on completion and supplying and labeling. All keys and handing over to Employer.

SPECIFICATIONS

1. ALUMINIUM DOOR, WINDOWS, AND CURTAIN WALLS

1.0 General Standards and System Description

1.1 Doors and Windows

Outer frame members shall be mitre cut with 45 degree angles and reinforced with extruded aluminium corner cleats securely jointed by mechanical crimps. Intermediate mullion and transom bars are square cut, machined, and securely fixed to outer frame with self tapping screws driven into screw receptacles in the profile joints which shall be sealed against entry

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of water. Glazing beads shall be angled to minimize dust concentration and air condition water sheds.

Where the sizes of door leaves, as recommended by Rukshan Widyalankara- Consultant, exceeds the recommended sizes and weights of the manufacturer, profiles should be reinforced with manufacturers standard reinforcing extrusions.

Weep holes for the draining of water shall be provided not be visible to exterior. No screws shall be visible, and rivets shall not be used in joinery. Perimeter sections that are in contact with the structure shall be provided with polystyrene or a suitable equivalent space fillers.

Marginal allowance of 5mm or as recommended by the sealant manufacturer shall be allowed when confirming the overall size of window. All pivoted doors shall be provided with concealed door closers with hold and open facility unless otherwise specified. All shopfront doors shall be provided with standard manufacturers thresholds with suitable backing strips.

Aluminium works shall confirm to BS 4873:1972 and BS 5286 for Aluminium Alloy Windows, or to any other Specifications incorporated in Contract by Rukshan Widyalankara- Consultant.

The performance of all installation shall confirm to BS 6375 Part 1 for Weather Tightness, BS 6375 Part 2 for Operations and Strength Characteristics, BS 5368 Part 1 for Air Permeability Test.

1.2 Stick Frame System Curtain Wall

All assembly components and the system in its entirety shall be designed to withstand a wind pressure of 33M/sec. or specified. Air infiltration, structural movement and stresses, and it's performance, shall confirm to BSS.

This system shall be based on "Rain Screen Principle" by providing weep holes on the face and underside of pressure plates, caps, and cill transoms, ensuring that the air pressure within glazing space equal to or approaching that of the external atmosphere. Outer gasket is located in stripped form as an integral part of the pressure plates providing primary weather seal. The external glazing gasket shall act as the weather seal, and the inner as the air seal. The inner gasket shall be constructed as a complete frame incorporating fully moulded corners to withstand air infiltration at high pressure.

The thermal insulation shall be achieved by using thermal breaks between pressure plates and main sections. It shall also work as a means of draining water downwards and as a cavity ventilation.

The glass shall lay on setting blocks mounted on sloping glazing platforms and drips shall be provided on transom nosing directing water into the gutter of pressure plate. End of transom shall be sealed with the mullion thereby separating each pain and forming discontinued air chambers for efficient drainage and pressure equalization.

Mullions shall be provided with primary structural support by means of insert tie backs precast to the structure, spanning in between floors in either tension or compression, and with joint sleeves at floor levels adjacent to the backs maintaining continuity of the mullion. Transoms shall be mechanically fixed by means of spigots and wet seals using appropriate sealants. All bolts, fasteners and fixings, shall be of stainless steel.

In-fills shall float with the framing matrix being located on extruded setting block at sill transoms. In-fills are mechanically retained by continuous pressure plates incorporating extruded gaskets which interlocks as a frame. Fixings shall be in stainless steel and a cover shall be snapped over pressure plate to express the required profile.

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2.0 Materials

2.1 Extrusions

Extrusions shall conform to BS 1474 for Aluminium Alloy HE 9TF or HE 9TE, or to any other specified by Rukshan Widyalankara- Consultant.

2.2 Inserts and tie backs in curtain walls.

Inserts shall be pre-galvanized cold rolled steel and pre-filled with expanded plastic forms and similar materials. Structural tie backs/ cleats shall be in structural framed aluminium alloy incorporating adjustment slots, isolators, and bolt fasteners.

2.3 Fire stops in Curtain Walls.

Fire stops shall be provided in relation to fire zones with 5mm steel/ galvanized sheets with PVC tapes between aluminium and steel.

2.4 Weatherstrips and Gaskets.

The gaskets shall be made from high grade PVC material to resist arduous climatic conditions conforming to BS 4255 Part 1 1968. External gasket shall act as a watershed and any internal glazing wedges or gaskets shall prevent any further penetration of air forming an air seal. Weatherstripping for sliding and shopfront doors shall be provided with polypropylene backed woven pile set in undercut grooves in frames and profiles.

2.5 Sealants.

Sealants shall conform to BS 5215:1975 and BS 5889:1980. Sealant for general sealing works shall be 1 part gun applied neutral curing sealants, which cures by absorption of moisture. Structural glazing silicone sealants shall be 2 part variable cure rate, high modules, elastomeric sealants with excellent performance properties. Sealants used at joints on fire checks/ fire resistant doors/ fire barriers, shall be of fire resistant quality, reinforced with inorganic fillers and fire retarding chemicals. The curing period for general sealants shall be 2-4 weeks under average conditions of humidity and atmosphere. After being fully cured, the sealant shall be able to accommodate movements and maintain a long lasting tough weather proof seal.

The joints made with sealants shall not be less than 6mm in depth and 4 times the expected movement in width. The depth of sealant should be half the width in the design of Joints, and if deeper in comparison to width, a backup material such as polyethylene strips shall be used.

Sealants shall be resistant to petrol, diesel, jet fuel, vegetable oil, and any other most weak alcoholic and dilute acids, and shall not form stain on materials such as concrete, masonry, stone, or wood. They shall have tack free time of 48 hours under average conditions.

Backing rods shall be provided to receive sealants at joints of perimeter section to structure.

2.6 Hardware

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Casement windows shall be hung from concealed stainless steel variable geometry adjustable friction stays with nylon friction pads. Restrictor stays shall be provided for limited opening with extruded aluminium loading handles. Metal to metal contact shall be avoided to ensure smooth operation by means of friction pads made of thermo plastic resins.

All hinges, locks, catches, handles, furniture, latches, opening devices, lever systems, and other remote control devices, stays, pulls, door closers, floor springs, safety bars, etc., required for specific operations and, all screws, nuts, washers, bolts, rivets, hardware and other miscellaneous fasteners, shall be of aluminium, stainless steel, or other non corrosive material, compatible with aluminium alloy and shall be of sufficient strength to perform the functions for which they are used.

Sashes of sliding doors should be on nylon rollers with stainless steel spindles in bottom rail of sash set into roller carriage. They should be provided with safety catches to restrict opening of sliding pane to two positions.

2.7 Coatings and Finishes

Anodic oxide coatings shall conform with BS 3987:1974 for external applications. Powder organic coatings, if specified by Rukshan Widyalankara- Consultant, for application and stoving of aluminium alloy extrusions sheet and pre formed sections for external architectural purposes shall comply with BS 6496.

2.8 Glazing

Glazing work shall comply with BS 6262 for thickness and type. Glass panes of casement windows shall be fitted with PVC gaskets for external beads, and by hard flexible vinyl or similar wedge gaskets for internal beads. Drainage to the exterior shall be provided.

Glass panes in sliding systems shall be set in extruded rubber channel gasket held in channel form receptacles in aluminium profiles and factory assembles.

2.9 Handling, Protection, Storage, and Cleaning.

2.9.1 Glass

The Contractor shall exercise great care to ensure that glass is not damaged in handling. Glass shall be stored under cover in vertical position in storage racks. All panels shall be cleaned and replaced if found to be damaged, at the Contractor's expense, prior to handing over of works.

2.9.2 Aluminium

All items under this section shall be delivered with a shop coat of transparent lacquer (or equivalent material recommended by manufacturers), to protect aluminium surfaces from cement, mortar, and other materials during construction. At the time of handing over, all works shall be left absolutely neat, clean, and in perfect working order, to the satisfaction of Rukshan Widyalankara- Consultant.

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Aluminium shall be washed down with only with clean soapy water. Metal polishes shall not be used as these may cause extensive damage to anodizing/coating.

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