a_m 11_structural steel (coatings)

8/18/2019 A_M 11_Structural Steel (Coatings)

1/30

STANDARDSPECIFICATIONS FOR

CONSTRUCTION WORKS

2008

MMoodduullee – – 1111 – – SSttrruuccttuurraall SStteeeell aanndd CCooaattiinnggss


2/30

Page 1

Introduction

The Standard Specifications are published as a series of 21 stand-alone modules each addressing

a single distinct area of the construction process. This stand-alone module 11 is an integral part of

the Standard Specifications.

The purpose of the MoW STANDARD SPECIFICATIONS FOR CONSTRUCTION is to provide the

design professional with a guide for accepted construction practices for Ministry of Works projects.

As an aid to the designer, these Standard Specifications are provided for the inclusion in proposed

development projects for ease, efficiency and cost savings.

The Standard Specifications are not intended to limit the design responsibility of the design

professional. However, they establish a minimum acceptable criterion and/or quality for use within

Ministry of Works projects.

The design professional may increase the requirements of an item contained in the Standard

Specifications to meet job requirements, but when this is done, there should be no reference for

that item on the drawings to the Ministry of Works Standard Specifications and a new specification

should be included with the drawings or project contract documents.

The design professional must review all Standard Specifications to be sure that they are adequate

for the proposed project based on the job site conditions; the design professional is solely

responsible for the designs submitted under his seal.

In order to keep design standards current with changing regulations and improved construction

materials and practices this section will be updated and maintained by the concerned authorities of

the Ministry of Works. Prior to starting a new project, the design professional should contact the

concerned Directorate of the Ministry of Works to verify that he/she has the latest document

revisions.


3/30

Page 2

Module List

ModuleNo Module Title

1 Guidance and General Specifications

2 Concrete

3 Earthworks

4 Glass and Glazing

5 Joinery and Carpentry

6 Ironmongery

7 Internal Finishes including Thermal Insulation

8 Painting and Decorating (Internal & External)

9 Metalwork

10 Roofing

11 Structural Steel (and Coatings)

12 Structural Timber

13 Masonry

14 Plumbing and Sanitary

15 Mechanical Installation in Buildings

16 Electrical Installation

17 Sewerage, Pipelines and Pipework

18 Sewerage M&E Works

19 Roadworks

20 Landscaping

21 Dredging, Reclamation and Shoreline Protection


4/30

Page 3

Table of Contents

CLAUSE DESCRIPTION PAGE

Introduction 1

Module List 2

Table of Contents 3

Foreword 4

1. PART 1 GENERAL 5

1.1 Scope………………………………………………………………………………. 5

1.2 Source Approvals………………………………………………………………… 5

1.3 Testing……………………………………………………………………………... 7

1.4 Submission of Drawings and Method Statements……………………………. 7

1.5 Care and Control of Materials…………………………………………………… 8

2.

PART 2 METHODOLOGY AND WORKMANSHIP 9

2.1

General…………………………………………………………………………….. 9

2.2 Bolted Connections………………………………………………………………. 9

2.3 Friction Grip Connections………………………………………………………... 9

2.4 Cambering………………………………………………………………………...10

2.5 Cutting……………………………………………………………………………. 10

2.6 Drilling……………………………………………………………………………..10

2.7 Welding…………………………………………………………………………... 10

2.8

Composite Floors………………………………………………………………...12

2.9

Foundations……………………………………………………………………… 13

2.10 Contractor’s Responsibilities……………………………………………………13

2.11 Erection……………………………………………………………………………14

2.12 As Built Drawings……………………………………………………………….. 14

3.

PART 3 SUMMARY 15

3.1 Codes of Practice……………………………………………………………….. 15

3.2 Publications……………………………………………………………………….16

4. PART 4 APPENDICES 17

4.1

Appendix A: Steelwork Coating and Fire Protection………………………… 17

Abbreviations 28


5/30

Page 4

Foreword

This specification provides the basis for using structural steel in construction. It covers the main

requirements for procurement, fabrication, erection and protective coating of structural steelwork.

This specification must be read in its entirety, as it is structured in order of work-flow, which means

that items or activities appear in several places in the specification corresponding to the

progression of the construction process.

For larger or more complex or specialist projects, a project-specific Particular Specification for

structural steelwork may also be provided.

Absence of clauses for materials and methods does not necessarily signify that they can not be

used. Proposals for use of innovative methods and materials are encouraged and are subject to

review and approval by the Client.

Where the word approved is used in this specification, this means that the Client or Engineer has

been consulted and has confirmed that the item or procedure is acceptable in the specific context

for which approval has been requested.


6/30

Page 5

1. PART 1 GENERAL

The supply, fabrication and erection of the structural steelwork shall be in accordancewith the general clauses of the National Structural Steelwork Specification for BuildingConstruction and the clauses of this Specification. In the event of any discrepancies theclauses of this Specification take precedence over and are in addition to the clauses ofthe National Structural Steelwork Specification.

1.1 Scope

This document outlines the requirements related to procurement, fabrication, erection andprotective coatings of structural steelwork which has been designed in accordance withBS 5950.

All references to Standards and Codes of Practice given hereafter shall be made to theeditions current at the time.

1.2 Source Approvals

1.2.1 Hot Rolled Steel

Steel for hot rolled sections, hot finished structural hollow sections, plates and bars shallcomply as a minimum with the basic specifications of BS EN 10025: Part 1 and BS EN10210: Part 1. Dimensional properties, tolerances and rolling margins for hot rolled steelmaterials shall comply with the following standards:

• plates and bars BS EN 10029

• universal beams, columns, rolled joists, channels and tees BS 4: Part 1

• rolled angles BS EN 10056

• structural hollow sections BS EN 10210: Part 2

1.2.2 Cold Formed Steel

Steel for cold formed welded structural sections shall comply as a minimum with the basic

specification of BS EN 10219: Part 1, and the following standards as applicable:

• Cold formed structural sections in uncoated steel shall be manufactured from strip inaccordance with BS1449: Part 1.

• Cold formed structural sections in zinc pre-coated steel shall be manufactured fromstrip in accordance with BS EN 10143.

• Cold formed longitudinally welded hollow sections shall be in accordance with BSEN 10219: Part 2.

• Purlins, side rails and accessories shall be manufactured from pre-hot-dippedgalvanized mild steel to BS EN 10143 with coating designation Z 275 and a minimumyield stress of 280 N/mm

2.

• All cold formed sections shall be formed by rolling, and not pressing.

• Dimensions and tolerances for cold formed steel materials shall comply with thefollowing standards:

o Cold rolled sections BS EN 10162o Cold formed hollow sections BS EN 10219: Part 2

1.2.3 Stainless Steel

Stainless steel for structural purposes shall be grade 316 S31 to PD 970 unless specifiedotherwise.


7/30

Page 6

1.2.4 Consumables

Consumables for use in metal arc welding shall comply with BS EN ISO 14341, BS ENISO 2560, BS EN 756, BS EN 757 and BS EN 760 as appropriate.

1.2.5 Structural Fasteners

Structural fasteners shall be in accordance with the following standards:

• Shop and site bolts and nuts in ordinary bolt assemblies shall be grade 4.6 inaccordance with BS 4190 or grade 8.8 or 10.9 in accordance with BS 3692 but withdimensions, tolerance and threaded length to BS 4190.

• High strength friction grip (HSFG) bolt assemblies shall be in accordance withBS 4395: Part 2.

• Stainless steel bolts, screws, studs and nuts shall be grade A4-80 to BS EN ISO3506 unless specified otherwise.

• Holding down bolts in foundations shall be in accordance with BS 7419.

• Cup and countersunk bolts shall be in accordance with BS 4933.

• Metal washers shall be made in accordance with BS 4320 Section 2 and unlessotherwise specified shall be black steel washers to Form E.

• All lock nuts shall be in accordance with BS EN ISO 2320 and BS EN ISO 7042 or

BS EN ISO 7719 as appropriate.• Where specific coatings are required to fasteners they shall be provided by the

fastener manufacturer and submitted to the Engineer for approval.

1.2.6 Shear Studs

Proprietary shear studs used in composite construction shall be in accordance withBS 5950: Part 3.1 and shall be the headed type with the following properties after beingformed:

• Minimum yield strength 350 N/mm2

• Minimum ultimate tensile strength 450 N/mm2

• At yield elongation of 15% on a 5.65√So gauge length, as given in BS EN 1002: Part1.

1.2.7 Protective Treatments

Protective treatment materials shall comply with the requirements of the followingstandards:

• Chilled iron shot and grit for blast cleaning shall be in accordance with BS EN ISO11124.

• Surface coatings shall be in accordance with the guidance given in BS EN ISO12944, BS EN ISO 14713 and/or specialist advice.

• Sherardized coatings shall be in accordance with BS 4921.

• Composition of zinc in galvanizing baths shall be in accordance with BS EN ISO1461.

• Lightweight gauge metalwork shall be galvanized by the hot-dip process as specified

in BS 3083 or BS EN 10143.

1.2.8 Surface Condition

The surface condition of steel for fabrication shall be in accordance with the followingstandards:

• Steel surfaces when used shall not be more heavily pitted or rusted than Grade C ofBS EN ISO 8501: Part 1.


8/30

Page 7

• Surface defects in hot rolled sections, plates, wide flats, round and square barsrevealed during surface preparation which are not in accordance with therequirements of BS EN 10163 for quality of finished steel, shall be rectifiedaccordingly.

• Surface defects in hot rolled hollow sections revealed during surface preparationwhich are not in accordance with the requirements of BS EN 10210: Part 1 shall berectified accordingly.

1.3 Testing

The Contractor shall perform tests and provide test certificates, or obtain and submit testcertificates from the manufacturers, for the materials to be used in the work.

The tests shall include the following, in accordance with BS EN 10025, BS EN 10210:Part 1, BS EN 10219: Part 1 and BS EN 10160 as appropriate:

• Chemical analysis

• Tensile strength tests

• Impact tests

• Bend tests• Lamination tests

The tests shall be carried out by an approved testing authority and notice shall be givenof the intended execution of any such tests.

If any sample fails a test the consignment it represents may be rejected in part or inwhole.

If necessary, additional tests shall be carried out by Inspection Authority selected by theEngineer in the event of apparent discrepancy between submitted certificates and actualcondition of the supplied material.

1.4 Submission of Drawings and Method Statements

The Contractor may amend the responsibilities of the Contractor defined in these

Specifications, subject to the prior notification and approval of the Engineer.

The Contractor shall submit for approval four initial copies of each fabrication drawingproduced by Contractor and subsequently four prints and one electronic copy of theapproved shop drawings for retention by the Engineer. Materials shall not be ordered norfabrication commenced until shop drawings are approved. Such approval shall not relievethe Contractor from any of his obligations and responsibilities under the contract.

In submitting drawings and erection procedures for approval, the Contractor shall allowsufficient time for review, comment, checking and re-submission as agreed with theEngineer.

The Contractor shall submit, as a minimum, the following information on or with thefabrication drawings:

• position of all plates, sections, stiffeners, welds, bolts, holes, shear connectors andtemporary attachments including type, size and orientation;

• length of plates and sections with a specified and calculation-supported allowancefor shrinkage and curvature caused by the method of fabrication, wherever suchdeviations may become critical for building tolerances;

• cambers which should allow for the pre-cambers given in the Contract Drawings;

• grades of structural materials and connectors.


9/30

Page 8

The Contractor shall maintain and submit a record of the source of all plate, section, boltand welding consumables, including test certificates.

At least 6 weeks prior to erection, the Contractor shall submit an erection methodstatement which shall include the following information:

• health and safety statement including procedures relating to safe working practice;

• sequence of programme for erection of steelwork and execution of protective coatingsystems, including drawings detailing crane and steelwork positions during erection,

lifting tackles, temporary props, supports and bracing;

• details of stationary lifting arrangements (tower cranes) including calculationsrelating to allowable ground pressures for crane supports;

• details of mobile lifting equipment including details of ground surface preparation incrane operation areas;

• procedures for site bolting, welding and corrosion protection;

• calculations relating to all props, supports and bracing required to maintain thestability of steelwork at all stages of erection;

• details of access to be provided for erection, bolting, welding, corrosion protectionand inspections by the Contractor’s Quality Personnel representatives and theEngineer.

1.5 Care and Control of Materials

1.5.1 Handling, Storage and Protection of Materials

• Steelwork shall be bundled, packed, handled and transported in a safe manner sothat permanent distortion does not occur and surface damage is minimised.

• All lifting tackle shall carry a current test certificate.

• Suitable packings, lashings, lifting harnesses, nylon slings, rubber protected chainsand chocks, etc. shall be used.

• Fabricated components shall be stacked clear of the ground, kept clean andsupported in such a manner as to avoid permanent distortion. If possible,accumulation of water from rain or condensation shall be avoided.

• Freshly applied surface coatings shall be protected from damage. 'Wet paint' signsand protective barriers shall be provided where necessary. Surfaces adjacent to

those being coated shall be protected.• Early degradation of coatings by blistering, peeling, flaking, cracking, lack of

adhesion, etc. shall be made good by complete removal, preparation andreapplication of all coats, as instructed.

• Inadequate dry film thickness or surface defects due to adverse weather may,depending on the type of paint, be remedied by rubbing down and applying furthercoat(s), as instructed.

• Mechanical damage to coatings shall be made good by local cutting back ofcoatings, preparation and reapplication of all coats to leave a neat, continuous andflat finish.

• Where damage to coatings or subsequent surface preparation has exposed baremetal, it must be thoroughly cleaned and primed within two hours.

• Consumables stored in the contractors works and on site shall be kept in acontrolled atmosphere, in accordance with BS EN 1011: Part 1.

1.5.2 Fabricated Material Control & Delivery

• Every component which is to be individually assembled or erected shall be allocateda unique erection mark. Members which are identical in all respects may have thesame erection mark. Individual pieces shall be capable of positive identification at allstages of fabrication.

• Completed components shall be marked with a durable and distinguishing erectionmark in such a way as not to damage the material. Hard stamping may not be used.


10/30

Page 9

Marks shall be placed, where possible, in positions where they will be visible instorage and after erection.

• All steel shall have a test certificate reference so that its properties are known andcan be verified.

2. PART 2 METHODOLOGY AND WORKMANSHIP

2.1 General

• All parts shall be cut, shaped and assembled to ensure accurate erection.

• Proprietary components, where used, shall be to manufacturers’ recommendations,and to the satisfaction of the Engineer.

• The ends of structural sections shall be cold sawn or machined except where specialpermission is granted for hot sawing.

• All plates and sections shall be true to form and free from twists, accuratelystraightened, planed or shaped as necessary.

• Where material lengths are incorrect, the extension of members by welding onadditional material will not be permitted.

• End connections of beams shall not have more than 2 mm clearance at each end,but cleats may project a maximum of 6 mm beyond the beam.

• Columns with ends not in direct bearing shall be fabricated to the accuracy requiredby Clause 7.2.2. of the National Structural Steelwork Specification, i.e. out ofsquareness not exceeding (depth of section)/300.

• Columns intended to be in direct bearing shall be fabricated to the accuracy requiredby Clause 7.2.3. of the National Structural Steelwork Specification i.e. out ofsquareness not exceeding (depth of section)/1,000.

2.2 Bolted Connections

• Bolts shall be threaded only over the length of shank which is outside the partsbolted together i.e. bearing must be made on unthreaded shank.

• The bolt shall protrude by at least two complete threads and not more than fourcomplete threads beyond the outer face of the tightened nut.

• Bolt holes shall not be distorted or enlarged by the use of drifts.

2.3 Friction Grip Connections

• High-strength friction grip bolts shall be fitted in accordance with BS 4604: Part 2.

• Faying surfaces of friction grip joints shall be immediately masked after blastcleaning and before coating surrounding areas to protect from contamination anddeterioration.

• If paint system comprises more than one coat, each coat shall be stepped 30 mmback from the edge of the preceding coat and away from masked areas.

• Immediately before bolting, masking shall be removed. Faying surfaces shall bechecked as free from adhesive, and cleaned with solvent if necessary.

• After final tightening of bolts, and inspection of joints:

o Uncoated areas including bolts shall be thoroughly degreased and cleaned.o Primer shall be applied without delay.o The full shop coating specification shall be applied.o Where direct tension indicators are used, measuring gaps shall be sealed to

prevent ingress of moisture.

• Load-indicating washers

o Load-indicating washers shall be installed in accordance with the manufacturer’srecommendations.


11/30

Page 10

o The load indicator protrusions should be oriented against the bolt heado The bolt head shall not be allowed to rotate against the protrusions

• The unit shall be tightened until the average gap is as indicated in the table below.

Table 1 – Load Indication Fitting for Friction Grip Connections

Load IndicatorFitting BS 4395Metric SeriesUnder Bolt Head General Grade Part 1 Higher Grade Part 2Black Finish Bolts 0.4 mm Max 0.5 mm Min 0.4 mm

All plating 0.4 mm Max 0.5 mm Min 0.4 mm

2.4 Cambering

Unless shown otherwise in the Contract Drawings, cambering shall be a smoothcontinuous curve. Selection of a curving or straightening process shall be agreed with theEngineer prior to execution.

2.5 Cutting

• Flame-cut edges which are free from significant irregularities shall be acceptedwithout further treatment except for the removal of dross; otherwise cut edges shallbe dressed to remove irregularities.

• Sniping of stiffeners at the root radii of rolled members shall be avoided whereverpossible. Stiffeners shall be cut to the required profile to fit closely into all such radii,and seal welded in accordance with the welding requirements hereafter.

2.6 Drilling

Bolt holes shall be drilled, punching is not allowed. Slotted holes shall be formed bydrilling two holes and completed by cutting. Holes in components shall be shown to thefollowing sizes.

For ordinary bolts and preloaded (HSFG) bolts:

• not exceeding 24 mm diameter, 2 mm greater than the bolt diameter

• greater than 24 mm diameter, 3 mm greater than the bolt diameter

For holding-down bolts:

• 6 mm greater than the bolt diameter, or with sufficient clearance to ensure that abolt, whose adjustment may cause it to be out of perpendicular, can beaccommodated through the base plate.

• Where cope holes are required to allow completion of butt welding they shall be ofadequate size to allow fillet welding to seal the connection, while still allowing fullaccessibility for subsequent painting.

2.7 Welding

2.7.1 Site Welding

In all cases precautions are to be taken so that the welding current does not damagecomponents it passes through and adequate return earth connections are made local tothe area being welded.

Welding shall not be permitted during inclement weather, unless adequate protectivemeasures are taken.


12/30

Page 11

2.7.2 Welders

• Welders employed on the work shall be tested to BS EN 287: Part 1 and Part 2, butin the case of welders engaged on fillet welding only, BS 4872: Part 1 is anacceptable alternative.

• Welder testing shall be witnessed and certificates endorsed by an independentInspection Authority. Copies of certificates for all welders shall be supplied to the

Engineer and the welder of any joint shall be shown to be qualified for the positionand type of weld proposed.

• Welding shall be carried out under the supervision of a competent weldingtechnologist and the test pieces shall be tested in accordance with BS EN ISO15614: Part 1.

• Documentation shall be maintained to enable welds to be traced to the welder whomade them.

• The Engineer has the right to instruct the Contractor to suspend any welder whoseperformance is deemed unsatisfactory.

2.7.3 Welding Methods

• Welding of steels to BS EN 10025 and BS EN 10210: Part 1 shall be metal arcprocess in accordance with the requirements of BS EN 1011: Part 1.

• Fillet welds shall be continuous to form a complete seal where two members join.Gaps at joints to be fillet welded shall not exceed 1 mm average (measured over 1 mor length of weld, whichever is smaller) and 2 mm maximum.

• Butt welds shall be full penetration welds. Butt welds in flanges and webs shall bedressed flush by grinding in the direction of stress.

• Run-on/run-off plates shall be used during butt welding. No temporary backing stripsshall be permitted.

• Penning of welds will not be permitted.

• Welding electrodes shall be of matching chemical composition to the parent metal incompliance with BS EN ISO 2560, and shall give a weld deposit with mechanicalproperties not less than the minimum specified for the parent metal.

• Hydrogen-controlled electrodes shall be used for butt welding of steel over 25 mmthick.

2.7.4 Weld Testing

Finished welds shall comply with Section 6 of API Standard 1104. Defective welds shallbe cut out, remade and retested until approved.

For surface flaw examination, magnetic particle inspection (MPI) shall be used. If MPI isimpractical, dye penetrant inspection (DPI) can be used in accordance with therecommendation given in BS EN 571: Part 1, with the permission of the Engineer.

The Contractor shall ensure that the welding processes are maintained to an acceptedstandard which is generally suitable for structural steelwork. The Engineer shall checkthat any additional project specific requirements for non-destructive testing (NDT) ofwelds are clearly specified in the Particular Specification. BS 5950: Part 2, Annex A maybe used as a reference for identifying critical welds which require additional inspection.Further details regarding scope of inspection, record of testing, visual inspection of welds

and surface flaw inspection can be provided if required.

2.7.5 Visual Inspection of Welds

• Visual inspection shall be made in accordance with guidance given in BS EN 970over the full length of all welds. Such inspection shall be performed before anyrequired NDT inspection.

• A suitably qualified person for visual inspection of welds may be a welding inspectoror a welder who can provide evidence of having been trained and assessed forcompetence in visual inspection of the relevant types of welds.


13/30

Page 12

2.7.6 Radiography Testing

Site-welded joints shall be inspected by radiography in accordance with Section 8 of APIStandard 1104. Initially 100% of each butt weld shall be inspected. At the discretion of theEngineer, the number of inspections may subsequently be reduced.

2.8 Composite Floors

2.8.1 Stud Welding

• Shear studs shall be through deck welded on site following erection of the profiledsteel decking.

• Top surfaces of beam flange shall be free from mill-scale, rust, grease, oil, paint, andother substances detrimental to welding. Flanges shall be cleaned prior to layingdecking.

• Studs shall not be welded if the deck is wet.

• The minimum distance from sheet edge to the hole made in a sheet by welding shallbe 25 mm.

• Before starting, suitability of materials, equipment and welding system proposed forwelding of studs shall be demonstrated. Not less than ten studs shall be fixed fortesting. Each trial weld shall exhibit full 360 degrees 'flash'. Each trial stud shall be

subjected to a 30 degree bend test; welds must show no sign of cracking. Testresults shall be retained for the Engineer’s inspection.

• Production welds shall be visually free from cracks and lack of fusion and capable ofdeveloping at least the nominal ultimate strength of the studs. 2% of all studs shallbe bent to 15 degrees to the vertical, to ensure continuing weld adequacy. Bentstuds are not required to be re-straightened.

2.8.2 Decking

• Floor decking shall be fixed (during layout) to the beams to ensure no gaps betweenbeams and deck, fixed by shot-firing or self drill-tap screws.

• Profiled decking shall be galvanized steel.

• Personnel shall not walk on the decking until after it has been fixed to the steelbeams. After fixing, access to the decking shall be via crawling boards. Any

damaged sheeting shall be replaced entirely at the Contractors expense. Delays indelivery of new sheets will not be considered as grounds for an extension of thecontract period.

• The Contractor shall ensure that no moisture is trapped between the beams anddecking, and provisions shall be made for boiling off any moisture prior to stud-welding.

• Joints in the decking shall be prepared to the manufacturer's recommendations (bytaping or mechanical fixing) to prevent grout leakage.

• Decking sheets are to be clean and free of all traces of grease or mould oilcontamination. The Contractor shall de-grease the decking to the satisfaction of theEngineer.

• Spacers for reinforcement shall be steel or concrete, in accordance with theConcrete Specification. The use of plastic spacers is not permitted.

• All ferrules shall be removed prior to placing the reinforcement or concrete.

2.8.3 Temporary Propping

• All propping for concrete work shall comply with the Concrete Specification.

• Where required by the design the Contractor shall provide, install and maintainpropping of all slabs as required until the design strength of the concrete has beenreached. Propping shall be in accordance with the deck suppliers’ recommendationsand shall be capable of transferring all loads to the ground or floors below withoutoverstressing any part of the structure. A full method statement shall be submittedand approval shall be obtained from the Engineer before installation.


14/30

Page 13

• Propping shall not be removed until the concrete in the slabs has achieved thedesign strength. The propping shall be progressively lowered in bays betweencolumns to ensure the loads taken by the propping are transferred uniformly to thecomposite construction.

2.9 Foundations

2.9.1 Holding Down Bolts

• The Contractor shall position the holding down bolts and sleeves in accordance withthe Contractor's Foundation Plan. The ends of bolts shall be held and linked by caststeel sections.

• Holding down bolts shall be protected by bituminous paint to the unthreaded partsbefore casting in, and all exposed parts and nuts shall be recoated after grouting andtightening.

• Holding down bolts shall be hand spanner tight when the base plates are grouted,and fully tightened at least 7 days after grouting to a controlled torque as specified bythe Engineer.

• Bolts shall be cast into foundations, using templates to ensure accurate positioningto the required line and level, within cylindrical pockets (sleeves). Anchor plates shallincorporate welded 'stops' to prevent bolt rotation during tightening.

• Neither bolts nor pockets shall be in contact with steel reinforcing bars. Immediatelyafter concreting in, all bolts shall be 'waggled' to ensure free movement within thepocket.

2.9.2 Grouting

• All grout and grouting shall comply with the Concrete Specification.

• The Contractor shall notify the Engineer if the space beneath any column base isless than 15 mm or more than 50 mm, and await his instructions before groutingunder any bases of the structure concerned.

• Bedding operations shall not commence until a sufficient number of columns,trusses, beams, bracings and ties have been properly lined, levelled, plumbed andfinally assembled.

• Immediately before grouting, pockets and spaces under the base plates shall be

thoroughly cleaned and excessive moisture removed.• Bolt pockets shall be filled with neat cement grout, just fluid enough to pour.

• Spaces under base plates shall be filled as follows:

o depth not exceeding 25 mm – Neat cement grout, just fluid enough to pour.o depth between 25 mm and 50 mm – Mortar of 1:2 cement : fine aggregate, just

fluid enough to pour. The mortar shall be tamped as filling proceeds.o In all cases care shall be taken to ensure that no pockets of air are trapped under

base plates. In larger base plates grout holes of appropriate size and locationshall be provided.

o In all cases a shrinkage compensating additive shall be incorporated in thematerial in accordance with manufacturer's recommendations.

• Grout or mortar shall have a minimum 28-day strength of 50 N/mm2. Packs shall be

protected by grout to a minimum thickness of 50 mm.

2.10 Contractor’s Responsibilities

• The Contractor shall inspect the prepared foundations and holding down bolts forposition and level not less than seven days before erection of steelwork starts. In theevent of any discrepancies found which are outside the permitted maximumdeviations, these shall be reported to the Engineer and the necessary remedial workshall be carried out before erection commences.


15/30

Page 14

• Accuracy of position and levels of foundations and holding down bolts shall be asspecified in the National Structural Steelwork Specification for Building Construction.

• It should be noted in particular that the permitted deviations for foundations andfoundation bolts are:

o Clause 9.4.1 – the maximum deviations of foundation level from exact level are+ 0 mm and - 30 mm;

o

Clause 9.4.3 – the maximum deviation of foundation bolt from exact location is20 mm in any direction horizontally and + 25 mm or - 5 mm vertically at shaft tip.

These are total deviations from the exact locations due to setting out inaccuracies as wellas construction allowance. Note also the required bolt movement in the location tube of25 mm minimum in all directions from the central position.

2.11 Erection

2.11.1 Approvals

The erection sequence and procedure shall be submitted for Engineer’s approval at anagreed time period prior to erection including the details of lifting plant and othermachinery. Prior to use, all lifting equipment shall be certified by an authorized third party

to be safe for use on site.

2.11.2 Contractor’s Responsibilities

Until the steelwork is accepted, the Contractor shall provide and maintain setting out linesand datum levels within or immediately adjacent to the Works. Before grouting undercolumn bases (or casting-in bases) the Contractor shall check the accuracy of thesteelwork erection and any errors shall be corrected.

The Contractor shall

• Achieve the design level of base plates during erection of columns, and steel platepacks or shims of appropriate thickness shall be used. It is not allowed to supportbase plates from levelling nuts.

• Be entirely responsible for stability of the steelwork during erection and shall arrangefor all temporary guying, bracing and supports, together with any additional tackboltsnecessary for structure stability until final bolting up. Use of tack welds shall belimited to an indispensable minimum.

• Assemble all parts as shown on the drawings and shall accurately position, plumb-line and level the work. Drift pins shall only be employed to align component partsand must not distort the work.

• Accurately erect the steelwork within the tolerances outlined in National StructuralSteelwork Specification and BS 5950: Part 1. In the event of discrepancy, thefollowing tolerances take precedence:

o Ensure that setting out/plan dimensions do not exceed ± 12 mm overall building

dimensions, or ± 5 mm in any one bay;

o Ensure that levels do not exceed ± 5 mm for truss and beam support plates, ± 10

mm stanchion base plates;o Ensure that stanchions are not out of plumb by more than 0.1% of height for

stanchions and vertical axis of truss girders, or 6 mm overall;o Ensure that after erection, straightness, bow or out-of-squareness shall be not

more than the rolling tolerances given in appropriate British Standards.

2.12 As-Built Drawings

The contractor shall produce all As-Built drawings before hand over, and format size andnumber shall be as specified in the contract.


16/30

Page 15

3. PART 3 SUMMARY

3.1 Codes of Practice

Reference Title

BS 4: Part 1 Structural steel sections. Specification for hot-rolled

sectionsBS 1449: Part 1 Steel plate, sheet and strip. Carbon and carbon-

manganese plate, sheet and stripBS 2989 Specification for continuously hot-dip zinc coated and iron-

zinc alloy coated steelBS 3083 Specification for hot-dip zinc coated and hot-dip

aluminium/zinc coated corrugated steel sheets for generalpurposes

BS 3692 ISO metric precision hexagon bolts, screws and nuts.Specification

BS 4190 ISO metric precision hexagon bolts, screws and nuts.Specification

BS 4320 Specification for metal washers for general engineeringpurposes. Metric series

BS 4395: Part 1 Specification for high strength friction grip bolts andassociated nuts and washers for structural engineering.General grade

BS 4395: Part 2 Specification for high strength friction grip bolts andassociated nuts and washers for structural engineering.Higher grade bolts and nuts and general grade washers

BS 4604: Part 1 Specification for the use of high strength friction grip boltsin structural steelwork. Metric series. General grade

BS 4604: Part 2 Specification for the use of high strength friction grip boltsin structural steelwork. Metric series. Higher grade (parallelshank)

BS 4872: Part 1 Specification for approval testing of welders when weldingprocedure approval is not required. Fusion welding of steel

BS 4921 Specification for sherardized coatings on iron or steel.

BS 4933 Specification for ISO metric black cup and countersunkhead bolts and screws with hexagon nuts

BS 5950 Structural use of steelwork in buildingBS 7419 Specification for holding down boltsPD 970 Wrought steels for mechanical and allied engineering

purposes. Requirements for carbon, carbon manganeseand alloy hot worked or cold finished steels

BS EN 287: Part 1 Qualification test of welders. Fusion welding. SteelsBS EN 287: Part 2 Approval testing of welders for fusion welding. Aluminium

and aluminium alloysBS EN 571: Part 1 Non-destructive testing. Penetrant testing. General

principlesBS EN 756 Welding consumables. Solid wires, solid wire-flux and

tubular cored electrode-flux combinations for submerged

arc welding of non alloy and fine grain steels. ClassificationBS EN 757 Welding consumables. Covered electrodes for manualmetal arc welding of high strength steels. Classification

BS EN 760 Welding consumables. Fluxes for submerged arc welding.Classification

BS EN 970 Non-destructive examination of fusion welds. Visualexamination

BS EN 1011: Part 1 Welding. Recommendations for welding of metallicmaterials. General guidance for arc welding

BS EN 10002: Part 1 Tensile testing of metallic materials. Method of test atambient temperature


17/30

Page 16

BS EN 10025 Hot rolled products of structural steelsBS EN 10029 Tolerances on dimensions, shape and mass for hot rolled

steel plates 3 mm thick or aboveBS EN 10056 Specification for structural steel equal and unequal leg

anglesBS EN 10143 Continuously hot-dip metal coated steel sheet and strip -

tolerances on dimensions and shape

BS EN 10160 Ultrasonic testing of steel flat product of thickness equal orgreater than 6 mm (reflection method)BS EN 10162 Cold rolled steel sections. Technical delivery conditions.

Dimensional and cross-sectional tolerancesBS EN 10163 Delivery requirements for surface condition of hot-rolled

steel plates, wide flats and sectionsBS EN 10210: Part 1 Hot finished structural hollow sections of non-alloy and fine

grain steels. Technical delivery requirementsBS EN 10210: Part 2 Hot finished structural hollow sections of non-alloy and fine

grain steels. Tolerances, dimensions and sectionalproperties

BS EN 10219: Part 1 Cold formed welded structural hollow sections of non-alloyand fine grain steels. Technical delivery requirements

BS EN 10219: Part 2 Cold formed welded structural hollow sections of non-alloyand fine grain steels. Tolerances, dimensions andsectional properties

BS EN ISO 1461 Hot dip galvanized coatings on fabricated iron and steelarticles. Specifications and test methods.

BS EN ISO 2320 Prevailing torque type steel hexagon nuts. Mechanical andperformance properties

BS EN ISO 2560 Welding consumables. Covered electrodes for manualmetal arc welding of non-alloy and fine grain steels.Classification

BS EN ISO 3506 Mechanical properties of corrosion-resistant stainless-steelfasteners

BS EN ISO 7042 Prevailing torque type all-metal hexagon nuts. Propertyclasses 5, 8, 10 and 12

BS EN ISO 7719 Prevailing torque type all-metal hexagon nuts, style 1.Property classes 5, 8 and 10

BS EN ISO 8501: Part 1 Preparation of steel substrates before application of paintsand related products. Visual assessment of surfacecleanliness. Rust grades and preparation grades ofuncoated steel substrates and of steel substrates afteroverall removal of previous coatings

BS EN ISO 11124 Preparation of steel substrates before application of paintsand related products

BS EN ISO 12944 Paints and varnishes. Corrosion protection of steelstructures by protective paint systems

BS EN ISO 14341 Welding consumables. Wire electrodes and deposits forgas shielded metal arc welding of non alloy and fine grainsteels. Classification

BS EN ISO 14713 Protection against corrosion of iron and steel in structures.zinc and aluminium coatings. Guidelines

BS EN ISO 15614: Part 1 Specification and qualification of welding procedures formetallic materials

3.2 Publications

National Structural Steelwork Specification for Building Construction.API 1104: Welding of Pipelines and Related Facilities


18/30

Page 17

4. PART 4 APPENDICES

4.1 Appendix A: Steelwork Coating and Fire Protection

Surface preparation and painting shall be carried out in accordance with good practice,generally but not exclusively laid down in such publications as BS 6150 ‘Code of Practicefor Painting of Buildings’, BS EN 12944 ‘Paints and varnishes. Corrosion protection of

steel structures by protective paint systems’, BS 7079 ‘Preparation of Steel SubstratesBefore Application of Paints and Related Products’, BS EN ISO 8501 to 8504‘Preparation of Steel Substrates Before Application of Paints and Related Products’.

Where the surface preparation or coating requirements of this specification differ fromthose of the approved manufacturer, the manufacturer's requirements shall takeprecedence, subject to the approval of the Engineer.

All references to Standards and Codes of Practice shall be made to the editions currentat the time.

4.1.1 Materials

4.1.1.1 Approved Systems

Coating systems proposed shall have a verifiable track record for use in climates similarto Bahrain.

The upper and lower limits provided for the Nominal Dry Film Thickness (NDFT) indicatethe minimum requirements for time to first maintenance of 10 years and 15 yearsrespectively. Where an upper limit is not provided, the time to first maintenance isexpected to be more than 10 years and less than 15 years.

The durability requirements for the project shall be defined in the contract documents.

Water-based coatings are preferred. Where water-based formulations are not available,preference shall be given to “high solids” systems that contain low fractions of volatileorganic compounds.

Coatings containing lead or chromate based pigments will not be approved.

4.1.1.2 Decorative Coatings

Decorative coatings for steel shall meet the requirements of the following coating systemslisted in Table 2 below:

Note: Decorative paint coatings shall only be applied to steel intended to be installed inair-conditioned environments.

Table 2 – Coating System for Decorative Coating

System ID Primer Topcoat NDFT m

System 1 Alkyd Alkyd 80-160System 2 Acrylic Acrylic 120-160System 3 Epoxy Poly-urethane 120-160

4.1.1.3 Protective Coatings

Protective coatings shall meet the requirements of the following coating systems listed inTables 3, 4 and 5 below:


19/30

Page 18

Note: Protective coating systems are defined based on the expected exposure condition.The exposure conditions are based on those described in BS EN ISO 12944-2 as follows:

• E1 equivalent to BS EN ISO 12944-2 (C3)

• E2 equivalent to BS EN ISO 12944-2 (C4)

• E3 equivalent to BS EN ISO 12944-2 (C5-M)

Exposure condition E1 shall apply to the interiors of non-air-conditioned buildings inurban areas.

Table 3 – Coating System for Protective Coating – Exposure Class E1

System ID Primer Topcoat NDFT mSystem 1 Alkyd Alkyd 160-200System 2 Acrylic Acrylic 160-240System 3 Epoxy Epoxy 160-240System 4 Epoxy Poly-urethane 160-240

Exposure condition E2 shall apply to the exteriors of buildings in urban areas greater than1,000 m from the coast and the interior of buildings containing swimming pools, orchemical processing facilities.

Table 4 – Coating Systems – Exposure Class E2

System ID Primer Topcoat NDFT mSystem 1 Acrylic Acrylic 240System 2 Epoxy Poly-urethane 240-320System 3 Epoxy-Zn-R Poly-urethane 200-320System 4 Ethyl-silicate

Zn-RPoly-urethane 200-320

Exposure condition E3 shall apply to the exteriors of all buildings less than 1,000 m fromthe coast and the interior of buildings containing almost permanent condensation or highpollution levels. Minimum coating thickness shall be as in Table 5 below:

Systems denoted by * shall only be applicable to applications where UV exposure is notexpected.

Table 5 – Coating Systems – Exposure Class E3

Primer Topcoat NDFT m

System 1* Epoxy - 400System 2* Epoxy-

Zn-REpoxy 300-500

System 3* Ethyl-silicate

Epoxy 240-320

System 3 Epoxy-Zn-R Poly-urethane 240-320System 4 Ethyl-silicate Poly-urethane 240-320

System 5 Epoxy Zn-R Epoxy-siloxane

200

4.1.1.4 Galvanizing

Hot dip galvanizing shall be in accordance with the requirements of BS EN ISO 1461.

The minimum coating thickness for steel work exposed to air-conditioned interiors ofbuildings or interior spaces where the exposure condition is E1 – as defined above – shallbe in Table 6 below:


20/30

Page 19

Table 6 – Galvanized Coating System – Exposure Class E1

Article Thickness Mean coatingthickness m

6 mm 85 3 mm to < 6 mm 70

1.5 mm to < 3 mm 55

< 1.5 mm 45

The minimum coating thickness for exterior steelwork where the exposure condition is E2 – as defined above – shall be as in Table 7 below:



6 mm 85

The minimum coating thickness for exterior steelwork where the exposure condition is E3 – as defined above – shall be as in Table 8 below:



6 mm 115 3 mm to < 6 mm 95

1.5 mm to < 3 mm 70

4.1.1.5 Fire Protection Coatings

The requirements for fire-protection shall be defined in the Particular Specification.Coating systems for the provision of fire-protection shall be limited to the systems listed inTable 9 below.

Table 9 – Fire Protection Coating System

System ID Primer Fire Protection Coating

System 1 Ethyl silicate Zn-R Thin film intumescent1

System 2 Epoxy Zn-R Intumescent epoxy masticSystem 3 Ethyl silicate Zn-R or

Epoxy Zn-RLightweight concrete

2

System 4 Ethyl silicate Zn-R orEpoxy Zn-R

Fire protection boards/casings

3

System 5 Ethyl silicate Zn-R orEpoxy Zn-R

Concrete4

Notes:

1 Thin intumescent coatings shall only be used in domestic/commercial internal

applications. They shall not be used for external or industrial type projects unlessapproved by the Engineer

2 Lightweight concretes shall generally comply with the Concrete Specification and shallbe proprietary mixes based on vermiculite or similar lightweight materials with aproven fire rating when tested in accordance with BS 476

3 Due to longer-term durability issues, fire-protection systems based on protectionboards or casings shall be applicable for internal applications only

4 Concrete shall comply with the Concrete Specification and shall provide a minimumcover of 50 mm to the element it is protecting. Where installation is external, the


21/30

Page 20

concrete shall be coated with a protective coating rated to Class 1 for flame spreadwhen tested in accordance with BS 476 Part 7.

The required fire rating shall be defined in the contract documents.

4.1.2 Approval of Systems

The Contractor shall submit details of the proposed coating systems for approval by theEngineer. Submittals shall include:

• Technical data for all materials including but not limited to the following:

o nominal recommended coating thicknesso surface preparation requirementso manufacturer approved application methodso available colourso over-coating intervals

• Samples of the proposed coating system

o A verifiable track record for the coating system for use in climates similar toBahrain.

For fire rated systems, test certificates indicating the performance of the material whentesting in accordance with the requirements of BS 476 shall be provided.

Materials shall be sourced from a single manufacturer.

Materials shall not be procured until they have been approved. Such approval shall notrelieve the Contractor from any obligations and responsibilities of the contract.

4.1.2.1 Alternative Systems

The Contractor shall be entitled to submit alternative systems for approval. Alternativesystems shall meet the durability requirements of the approved systems. Theirperformance shall be documented and evidence shall be submitted for approval by theClient.

4.1.3 Handling, Storage and Protection of Materials

4.1.3.1 Safety

Hazards associated with the handling and storage of materials shall be defined andcontrol measures identified and included in the Contractor’s method statements.

Safe handling practices shall be adhered to at all times. Personnel shall be trained in thesafe handling, and storage or materials.

• Control of Volatile Organic Compounds

Materials shall be stored, prepared and applied in well ventilated areas. Whereadequate ventilation is not practically achievable, painters shall be provided withsuitable respiratory devices to prevent ingestion of vapours.

• Fire Safety

Materials shall be stored away from potential ignition sources. Smoking shall beprohibited on sites where flammable materials are being stored or applied.


22/30

Page 21

Fire hazards shall be assessed and controls defined in the Contractor’s methodstatements.

4.1.3.2 Storage

All materials shall be stored in a secure air-conditioned area. Unless other temperaturesare indicated in the manufacturer’s instructions or specified elsewhere, coating materials

shall be stored at temperatures above + 3°C and under + 30°C. Materials shall only betaken to site as required by planned coating operations. Containers shall remain sealeduntil the contents are prepared for use.

Partly used containers may be re-sealed and used later unless otherwise advised by themanufacturer. Partly used containers shall be clearly marked.

Steelwork protected by only prefabrication primer shall not be stored outside for morethan 21 days.

If damage has exposed parent metal, local re-blasting may be required to prepare thesteel for remedial coating. The maximum time lag between cleaning steel and applyingprimer shall not be more than two hours.

4.1.3.3 Shelf Life

Materials shall not be used beyond their specified shelf life.

When any mixed 2 pack material has exceeded its pot life it should be discardedirrespective of its apparent condition.

Labelling and date stamps:

All containers shall be clearly identifiable and shall be machine labelled with the followinginformation:

o Manufacturer’s nameo Material nameo Mass/Volume of contents of containero Date of Manufactureo Expiry date or expected shelf lifeo Batch and/or production numbero Material’s hazard classification (if applicable)o Recommended storage temperature

4.1.4 Methodology and Workmanship

4.1.4.1 Approvals

• Method Statements

The Contractor shall submit detailed method statements for the coating work. Thesubmittal shall include but not be limited to the following:

o Technical data sheets and material safety data sheets (MSDS) for all productsproposed

o Details of proposed surface preparation methods and materialso Details of proposed application methodso Details of equipment to be usedo Details of Personal Protective Equipment requiredo Details of safe handling controlso Methods for protecting finished coatings during transport and erection on siteo Details of fire safety controlso Nominated safety officers


23/30

Page 22

• Inspection and Test Plan

The Contractor shall submit an Inspection and Test Plan (ITP) that details qualityand safety hold points and inspections for all stages of the works including surfacepreparation, materials preparation and application as detailed in the methodstatements.

4.1.4.2 Preparation

• Cleaning

Accumulated dirt, grease and soluble salts shall be removed and the steelworkcleaned in accordance with BS 7079. Dry bristle brushing shall normally beadequate for accumulated dirt. Soluble salts shall be removed by fresh waterwashing.

• Preparation of Welds/Edges

Sharp edges shall be rounded or chamfered. All burrs from holes shall be removedprior to blasting.

All welds shall be free of undercutting, craters and splatters. Splatters shall beremoved by suitable methods prior to blast cleaning.

• Blast Cleaning

All surfaces shall be blast cleaned with to a minimum standard of Sa 2½ (ISO 8501:Part 1). Surface profile shall be in accordance with recommendations from thecoating manufacturer.

For galvanized elements, the surface shall be prepared by sweep blast, cleaned tosurface roughness “fine (G)” in accordance with ISO 8503: Part 2.

Abrasives based on silica-containing materials shall not be used.

After blast cleaning all dust and debris shall be removed by vacuum cleaner or oilfree compressed air and brush. Freedom from residual surface contamination shallbe checked by pressing the adhesive side of transparent adhesive tape onto thecleaned surface and on removal examining it for adherent rust, scale or dust.

• Cleaning Prior to Hot Dip Galvanizing

All steel articles shall be cleaned by acid pickling to remove mill scale, oils and otherprotective films prior to hot dip galvanizing.

• Safety

Personnel involved in surface preparation shall be trained to a recognized standardand shall wear the appropriate Personal Protective Equipment that shall include but

not be limited to:

o Eye protectiono Hearing protectiono Respiratory protection

Areas where surface preparation works are carried out shall be clearly demarcatedwith warning signs/barriers. Access to the work site during surface preparation shallbe limited to those carrying out the works.


24/30

Page 23

Access to the work site for other personnel shall only be upon a clearly definedsignal as defined in the Contractor’s Safety Management Plan.

• Period Between Surface Preparation and Coating

The period between surface preparation and coating shall be kept to the minimumthat is practically achievable. Where periods between surface preparation and

coating may be sufficient for the preparation grade to change (e.g. by formation ofrust), temporary protection such as pre-fabrication primers or adhesive films shall beprovided.

Further preparation will be required prior to coating application.

4.1.4.3 Galvanizing

• Galvanizing of steelwork shall be carried out after fabrication is complete inaccordance with BS EN ISO 1461.

• Steelwork required to be galvanized shall be pickled in dilute hydrochloric acid,washed, fluxed and stoved, and then coated with zinc by dipping in a bath of moltenzinc. Components shall be immersed in the bath only for a period sufficient to attainthe temperature of the bath, and shall be withdrawn at a speed which ensures thatthe coating of 610 g/m

2 of surface is achieved (85 microns minimum DFT).

• Components shall be covered evenly on all surfaces and shall be free from pinholes, lumps of galvanizing materials and all other defects.

• Items described as heavily galvanized shall be grit blasted prior to galvanizing andshall receive a minimum coating of 1,000 g/m

2 of surface (140 microns minimum

DFT).

• Before application of the specified paint treatment, galvanized steelwork shall becleaned, degreased and etch primed.

• All damaged galvanizing surfaces and all edges exposed by cutting, drilling orwelding after galvanizing shall be treated with two coats of sprayed metallic zinc inaccordance with manufacturer specification, prior to restoring of paint system.

• Contact between galvanized steel members and aluminium surfaces or betweengalvanized and ungalvanized steel members shall be prevented by means ofapproved insulating washers and grommets.

4.1.5 Application

4.1.5.1 General

Prior to and during the application, the Contractor shall verify coating materials to ensure:

• conformity of the container label with the specified product description

• no skin formation

• no irreversible settling

• usability under the given site conditions

Where viscosity modification is required it shall be made in strict accordance with themanufacturer’s recommendations.

4.1.5.2 Safety

Personnel involved in surface preparation shall be trained to a recognized standard andshall wear the appropriate Personal Protective Equipment that shall include but not belimited to:

• Eye protection

• Hearing protection (as applicable)

• Skin protection (gloves or barrier cream as appropriate)

• Respiratory protection


25/30

Page 24

4.1.5.3 Shop Coating

Where fabrication methods allow, all coating shall be completed in a dedicated coatingfacility.

All completed coatings shall be protected from damage during storage and duringtransport to the site.

4.1.5.4 Site Coating

Where fabrication methods do not allow shop coating or where touch-ups or final coatson connections are required, site coating shall be allowed.

Containment shall be provided to ensure abrasive used for blast cleaning and coatingoverspray is contained local to the works.

The containment shall also offer the area of any works adequate protection from rain andwind.

Ideally the containment should be able to control the local environment to the ambientconditions detailed in this specification throughout the preparation and paintingoperations and including the initial drying and curing of the applied paints.

4.1.5.5 Ambient Conditions

Coating application should only be carried out when good atmospheric conditions andclement weather prevail.

The surfaces to be treated shall be safely accessible and well illuminated.

Coating should not be undertaken:

• When the air temperature falls below the lower drying or curing limit of the coating

• During fog or mist conditions or when rain is imminent

• When the surface to be painted is wet with condensation or when condensation canoccur during the initial drying period of the coating

• When the amount of moisture likely to be deposited on the surface by condensationor rain immediately after coating, may have a harmful effect on the coating

• When the ambient temperature falls below 10°C

• When substrate is below 10°C

• When the relative humidity rises above 85%.

• When the ambient temperature is less than 3°C above the dew point

• When the substrate or ambient temperatures are above 40°C

• When wind-borne dust may have a harmful effect on the coating.

In order to determine whether or not a surface is wet, the steel temperature should bemeasured using a surface temperature thermometer and the dew point calculated aftermeasurement of humidity with a hygrometer. Coating application should not take placewhen steel temperature is less than 3°C above the dew point.

4.1.5.6 Mixing

All components of the coating materials shall be prepared strictly in accordance with themanufacturer’s printed requirements.

Mixing equipment shall be clean and dry and not contaminate the materials in any way.

4.1.5.7 Pot Life

Coatings shall not be used beyond the pot life specified by the manufacturer or when it isobviously thickening.


26/30

Page 25

4.1.5.8 Application Methods

All coatings shall be applied in accordance with the requirements of the manufacturer.

Where concrete is used for fire protection, installation shall be in accordance with theConcrete Specification.

Coating application methods shall include but not be limited to the following:

• Brush

• Roller

• Trowel

• Airless spray

The application method shall be determined in accordance with the manufacturer’srecommendations and any other factors that may affect the suitability of a particularmethod. The application method shall be included in the method statement submittal forreview by the Engineer.

All application equipment shall be cleaned at the commencement of painting and shall bekept clean during the painting operation, using the cleanser specified for the particular

paint. Brushes stored in thinners shall be well worked out to remove thinners before use.

4.1.5.9 Coating Thickness

All materials shall be applied at the manufacturer’s recommended thickness, but thecompleted coating system must meet the minimum dry film thickness defined in theproject specification.

Unless agreed otherwise, individual dry film thicknesses of less than 80% of the nominaldry film thickness are not acceptable.

Stripe coats shall be applied to all welds, lap joints, plate edges, corners, sharp edges,and any other edges where spray application of the overall coating system may provedifficult resulting in low dry film thicknesses.

Wet film thickness gauges shall be used regularly to check adequate wet material isapplied meet the recommended application rates for each coat.

4.1.5.10 Testing

The type and frequency of testing shall be identified in the inspection and test plan.Testing shall include but not be limited to:

• Surface comparator testing (if particular profile is required by coating manufacturer)

• Wet film thickness testing

• Dry film thickness testing

• Pull-off testing

• Spark testing

During application wet film thickness of each coat shall be checked with a wheel or combgauge used in accordance with BS EN ISO 2808.

After each coat has dried, check total accumulated film thickness using a magnetic orelectromagnetic meter.

Average dry film thickness shall be at least specified thickness over any square metreand no reading to be less than 75% of the specified thickness.

Top coat dry film thickness shall be sufficient to give an even, solid, opaque appearance.


27/30

Page 26

Measurements to be independently witnessed.

Check meter against standard shims and recalibrate regularly against a smooth steelreference plate.

4.1.5.11 Period between Over-coating

Over-coating periods shall be strictly in accordance with the paint manufacturer’s printed

requirements.

Surfaces to be over-coated shall be clean and dry and prepared as required by themanufacturer.

4.1.5.12 Colour of Coats

To enable clear identification of coats, the primer, intermediate and top coats shall be ofdifferent shades subject to the opacity of the final coat.

The final coat colour shall be defined in the contract documents.

The colour shall be as defined in the contract documents at the end of the warrantyperiod.

4.1.5.13 Special Requirements

• Connections:

Where fabricated items are to be subsequently welded on site, the coating systemshall not be applied within 150 mm of the weld.

Where steelwork is galvanized, the galvanizing shall be removed from the weld areato provide a minimum of 75 mm clearance from the weld.

• HSFG bolt connections:

Coatings shall be carefully selected to ensure that the friction factor does not affectthe ability of the connection to perform as designed.

Friction type bolted connections shall be blast cleaned to Sa 2½ in accordance withISO 8501: Part 1 with an agreed roughness. The friction surfaces can be coated witha material with a suitable friction factor.

4.1.5.14 Re-work

Where testing indicates that the coating does not meet the requirements defined in thecontract documents, the coating shall be made good by complete removal of all coats,preparation of the surface and re-application of the coating system in accordance with thecontract documents.

Where localised repairs are required, the coating shall be made good by local cutting-back of the coating, preparation of the surface and re-application of the coating system inaccordance with the contract documents.

4.1.6 Reference Documents

4.1.6.1 Standards

Reference Title

BS 476 Fire tests on building materials and structuresBS 5950 The structural use of steelwork in buildingsBS 6150 Painting of buildings. Code of practice


28/30

Page 27

BS 7079 General introduction to standards for preparation of steelsubstrates before application of paints and relatedproducts

BS EN ISO 1461 Hot dip galvanized coatings on fabricated iron and steelarticles. Specifications and test methods

BS EN ISO 2808 Paints and varnishes. Determination of film thicknessBS EN ISO 8501 Preparation of steel substrates before application of paints

and related products. Visual assessment of surfacecleanlinessBS EN ISO 8502 Preparation of steel substrates before application of paints

and related products. Tests for the assessment of surfacecleanliness

BS EN ISO 8503 Preparation of steel substrates before application of paintsand related products. Surface roughness characteristics ofblast-cleaned steel substrates

BS EN ISO 8504 Preparation of steel substrates before application of paintsand related products. Surface preparation methods

BS EN ISO 9002 Quality systems. Model for quality assurance in production,installation and servicing

BS EN ISO 12944 All parts Paints and varnishes. Corrosion protection ofsteel structures by protective paint systems

BS EN ISO 14713 Protection against corrosion of iron and steel in structures.Zinc and aluminium coatings. Guidelines

4.1.6.2 Publications

Fire protection for structural steel in buildings, 3 rd

Edition, (2004),Association for Specialist Fire Protection, UKISBN 1 870409 22 1

Spray coatings for the protection of structural steel – Part 1: Technical guidance note forthe mechanical retention of sprayed mineral coatings based upon the requirements of BS8202: Part 1: 1993 , Association for Specialist Fire Protection, UKISBN 1 870409 11 6


29/30

Page 28

Abbreviations

ACB Air Circuit Breakers EMC Electromagnetic CompatibilityACOPACRIB

Approved Code of PracticeAir Conditioning and Refrigeration Industry

EPDM Ethylene-propylene-diene-monomercopolymer

Board FA Fresh Air

ADCMAFMA Acoustic Doppler Current MetersAustralian Fisheries Management Authority FBAFRP Factory Built AssemblyFibre Reinforced PolymerAGMA American Gear Manufacturers’ Association FSC Forest Stewardship CouncilAISIAS

American Iron and Steel InstituteAcceptance Strength

GANAGGBS

Glass Association of North AmericaGround Granulated Blast-furnace Slag

ASTA Association of Short-circuit TestingAuthorities

GMSGRC

Galvanized Mild SteelGlass Reinforced Cement/Glass Reinforced

ASTM American Society for Testing Materials ConcreteATS Automatic Transfer Switch GRP Glass Reinforced PlasticsAWS American Welding Society HCFC HydrofluorocarbonsBASEC British Approval Service for Electric Cables HDPE High Density PolyethyleneBOCA Building Officials and Code Administrators HEPA High Efficiency Particulate AirBRE Building Research Establishment Ltd. HFC HydroFluoroCarbonBSBSRIA

British StandardsBuilding Service Research and Information

HPLHPPE

High Pressure LaminateHigher Performance Polyethylene

Association HRC High Rupturing Capacity

CBR California Bearing Ratio HSE Health and Safety ExecutiveCCTV Close Circuit Television HSFG High Strength Friction GripCECOMAF Comité Européen des Constructeurs de

Matériel FrigorifiqueHVHVCA

High VoltageHeating and Ventilating Contractors’

CENELEC Comité Européen de NormalisationElectrotechnique ICBO

AssociationInternational Conference of Building Officials

CFC Chlorofluorocarbons IGCC Insulating Glass Certification CouncilCIBSE Chartered Institution of Building Services

EngineersIGE/UP Institution of Gas Engineers – Utilization

ProceduresCHW Chilled Water IP Ingress ProtectionCI Cast Iron ISAT Initial Surface Absorption TestCLW Cooling Water ISO International Standard OrganizationCM Current Margin / Communication cable ITP Inspection Testing PlanCMPCP

Communication cable (Plenum)Code of Practice

KDkVA

Kiln DriedKilovolt Ampere

CPC Circuit Protection Conductor LCD Liquid Crystal Display

CPT Cone Penetration Testing LED Light Emitting DiodeCRSCRT

Categorised Required StrengthCathode Ray Tube

LPGLS0H

Liquid Petroleum GasLow Smoke Zero Halogen

CRZ Capillary Rise Zone LSF Low Smoke and FumeCT Current Transformer LV Low Voltagec(UL) Underwriters Laboratories Incorporated

(Canada)MCBMCC

Miniature Circuit BreakerMotor Control Centre

DEO Defence Estate Organisation MCCB Moulded Case Circuit BreakersDFT Dry Film Thickness MDF Medium Density FireboardDI Ductile Iron MDD Maximum Dry DensityDINDPC

Deutsches Institut für NormungDamp Proof Course

MDPEMEP

Medium Density PolyethyleneMechanical Electrical Plumbing

DPDT Differential Pressure, DifferentialTemperature

MICCMIO

Mineral Insulated Copper Covered CableMicaceous Iron Oxide

DS Durability Strength MMI Man Machine InterfaceDVR Digital Video Recorder MOD Ministry of DefenceDW Ductwork Specification MS Micro-silicaEA Exhaust Air MSDS Material Safety Data SheetECMA European Computer Manufacturers

AssociationMSRPC Moderate Sulphate Resistance Portland

CementEA Exhaust Air N NitrogenECMA

ECR

European Computer ManufacturersAssociationExtra Chemical Resistant

NDFTNEMANFPA

Nominal Dry Film ThicknessNational Electrical Manufacturers’ AssociationNational Fire Protection Association

EIA Environmental Impact Assessment/Electronic Industries Alliance

NRCNS

Noise Reduction CoefficientNorwegian Standard


30/30

O/D Outside DiameterODP Ozone Depletion PotentialOFS Oil Fired (Appliance/Equipment) StandardOFTEC Oil Firing Technical AssociationO&M Operation and MaintenanceOPC Ordinary Portland CementPD Published DocumentsPE Polyethylene

PFA Pulverised Fuel AshPFC Power Factor CorrectionPM Project ManagerPTFE PolytetrafluoroethylenePVC PolyvinylchloridePVC-u Unplasticised PolyvinylchloridePWTAG Pool Water Treatment Advisory GroupQA/QC Quality Assurance/Quality ControlRA Return/Recycled AirRCCD Residual Current Circuit BreakerRCD Residual Current DeviceR&D Research and DevelopmentREFCOM Register of Companies Competent to handle

refrigerantsRPM Reinforced Plastic MortarRPZ Reduced Pressure Zone

RTD Resistant Temperature DetectorRTR Reinforced Thermosetting ResinSA Supply AirSBCCI Southern Building Code Congress

International (Incorporated)SDR Standard Dimension RatioSIS Swedish Institute of StandardsSP Super-plasticizingSPDT Single Pole Double ThrowSRPC Sulphate Resistance Portland CementSS Structural StrengthSSPC Steel Structures Painting CouncilTIA Telecommunication Industry AssociationTRA Trussed Rafter AssociationUL Underwriters Laboratories IncorporatedULPA Ultra Low Penetration Air

UP Unsaturated Polyester ResinUPS Uninterruptible Power SupplyUTP Unshielded Twisted PairUV Ultra VioletVC Vitrified ClayVR Video RecorderWBP Weather and Boil ProofW/C Water Cement RatioWIS Water Industry SpecificationWP Water ProofingWRAS Water Regulations Advisory SchemeXLPE Cross Linked Polyethylene