Structural Steel (coatings).pdf

STANDARD SPECIFICATIONS FOR CONSTRUCTION WORKS

2008

Module – 11 – Structural Steel and Coatings

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.

Page 1

Module List Module No

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

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Table of Contents CLAUSE

DESCRIPTION

PAGE

Introduction

1

Module List

2

Table of Contents

3

Foreword

4

1.

PART 1 GENERAL

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

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

3.1

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

3.2

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

4.

PART 4 APPENDICES

4.1

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

Abbreviations

5

9

15

17

28

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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.

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1.

PART 1 GENERAL The supply, fabrication and erection of the structural steelwork shall be in accordance with the general clauses of the National Structural Steelwork Specification for Building Construction and the clauses of this Specification. In the event of any discrepancies the clauses of this Specification take precedence over and are in addition to the clauses of the National Structural Steelwork Specification.

1.1

Scope This document outlines the requirements related to procurement, fabrication, erection and protective coatings of structural steelwork which has been designed in accordance with BS 5950. All references to Standards and Codes of Practice given hereafter shall be made to the editions 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 shall comply as a minimum with the basic specifications of BS EN 10025: Part 1 and BS EN 10210: Part 1. Dimensional properties, tolerances and rolling margins for hot rolled steel materials shall comply with the following standards: • • • •

1.2.2

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

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 in accordance with BS1449: Part 1. Cold formed structural sections in zinc pre-coated steel shall be manufactured from strip in accordance with BS EN 10143. Cold formed longitudinally welded hollow sections shall be in accordance with BS EN 10219: Part 2. Purlins, side rails and accessories shall be manufactured from pre-hot-dipped galvanized mild steel to BS EN 10143 with coating designation Z 275 and a minimum yield stress of 280 N/mm2. All cold formed sections shall be formed by rolling, and not pressing. Dimensions and tolerances for cold formed steel materials shall comply with the following standards: o Cold rolled sections BS EN 10162 o 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 specified otherwise.

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1.2.4

Consumables Consumables for use in metal arc welding shall comply with BS EN ISO 14341, BS EN ISO 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: • • • • • • • •

1.2.6

Shop and site bolts and nuts in ordinary bolt assemblies shall be grade 4.6 in accordance with BS 4190 or grade 8.8 or 10.9 in accordance with BS 3692 but with dimensions, tolerance and threaded length to BS 4190. High strength friction grip (HSFG) bolt assemblies shall be in accordance with BS 4395: Part 2. Stainless steel bolts, screws, studs and nuts shall be grade A4-80 to BS EN ISO 3506 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 unless otherwise 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.

Shear Studs Proprietary shear studs used in composite construction shall be in accordance with BS 5950: Part 3.1 and shall be the headed type with the following properties after being formed: • • •

1.2.7

2

Minimum yield strength 350 N/mm 2 Minimum ultimate tensile strength 450 N/mm At yield elongation of 15% on a 5.65√So gauge length, as given in BS EN 1002: Part 1.

Protective Treatments Protective treatment materials shall comply with the requirements of the following standards: • • • • •

1.2.8

Chilled iron shot and grit for blast cleaning shall be in accordance with BS EN ISO 11124. Surface coatings shall be in accordance with the guidance given in BS EN ISO 12944, 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 ISO 1461. Lightweight gauge metalwork shall be galvanized by the hot-dip process as specified in BS 3083 or BS EN 10143.

Surface Condition The surface condition of steel for fabrication shall be in accordance with the following standards: •

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

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•

•

1.3

Surface defects in hot rolled sections, plates, wide flats, round and square bars revealed during surface preparation which are not in accordance with the requirements of BS EN 10163 for quality of finished steel, shall be rectified accordingly. Surface defects in hot rolled hollow sections revealed during surface preparation which are not in accordance with the requirements of BS EN 10210: Part 1 shall be rectified accordingly.

Testing The Contractor shall perform tests and provide test certificates, or obtain and submit test certificates 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 given of the intended execution of any such tests. If any sample fails a test the consignment it represents may be rejected in part or in whole. If necessary, additional tests shall be carried out by Inspection Authority selected by the Engineer in the event of apparent discrepancy between submitted certificates and actual condition 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 drawing produced by Contractor and subsequently four prints and one electronic copy of the approved shop drawings for retention by the Engineer. Materials shall not be ordered nor fabrication commenced until shop drawings are approved. Such approval shall not relieve the Contractor from any of his obligations and responsibilities under the contract. In submitting drawings and erection procedures for approval, the Contractor shall allow sufficient time for review, comment, checking and re-submission as agreed with the Engineer. The Contractor shall submit, as a minimum, the following information on or with the fabrication drawings: • • • •

position of all plates, sections, stiffeners, welds, bolts, holes, shear connectors and temporary attachments including type, size and orientation; length of plates and sections with a specified and calculation-supported allowance for shrinkage and curvature caused by the method of fabrication, wherever such deviations 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.

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The Contractor shall maintain and submit a record of the source of all plate, section, bolt and welding consumables, including test certificates. At least 6 weeks prior to erection, the Contractor shall submit an erection method statement 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 coating systems, including drawings detailing crane and steelwork positions during erection, lifting tackles, temporary props, supports and bracing; details of stationary lifting arrangements (tower cranes) including calculations relating to allowable ground pressures for crane supports; details of mobile lifting equipment including details of ground surface preparation in crane operation areas; procedures for site bolting, welding and corrosion protection; calculations relating to all props, supports and bracing required to maintain the stability of steelwork at all stages of erection; details of access to be provided for erection, bolting, welding, corrosion protection and inspections by the Contractor’s Quality Personnel representatives and the Engineer.

1.5

Care and Control of Materials

1.5.1

Handling, Storage and Protection of Materials • • • • • • • • • •

1.5.2

Steelwork shall be bundled, packed, handled and transported in a safe manner so that 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 chains and chocks, etc. shall be used. Fabricated components shall be stacked clear of the ground, kept clean and supported 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'signs and 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 and reapplication 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 further coat(s), as instructed. Mechanical damage to coatings shall be made good by local cutting back of coatings, preparation and reapplication of all coats to leave a neat, continuous and flat finish. Where damage to coatings or subsequent surface preparation has exposed bare metal, it must be thoroughly cleaned and primed within two hours. Consumables stored in the contractors works and on site shall be kept in a controlled atmosphere, in accordance with BS EN 1011: Part 1.

Fabricated Material Control & Delivery •

•

Every component which is to be individually assembled or erected shall be allocated a unique erection mark. Members which are identical in all respects may have the same erection mark. Individual pieces shall be capable of positive identification at all stages of fabrication. Completed components shall be marked with a durable and distinguishing erection mark in such a way as not to damage the material. Hard stamping may not be used.

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•

Marks shall be placed, where possible, in positions where they will be visible in storage and after erection. All steel shall have a test certificate reference so that its properties are known and can be verified.

2.

PART 2 METHODOLOGY AND WORKMANSHIP

2.1

General • • • • • • • •

2.2

Bolted Connections • • •

2.3

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 special permission is granted for hot sawing. All plates and sections shall be true to form and free from twists, accurately straightened, planed or shaped as necessary. Where material lengths are incorrect, the extension of members by welding on additional 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 required by Clause 7.2.2. of the National Structural Steelwork Specification, i.e. out of squareness not exceeding (depth of section)/300. Columns intended to be in direct bearing shall be fabricated to the accuracy required by Clause 7.2.3. of the National Structural Steelwork Specification i.e. out of squareness not exceeding (depth of section)/1,000.

Bolts shall be threaded only over the length of shank which is outside the parts bolted together i.e. bearing must be made on unthreaded shank. The bolt shall protrude by at least two complete threads and not more than four complete threads beyond the outer face of the tightened nut. Bolt holes shall not be distorted or enlarged by the use of drifts.

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 blast cleaning and before coating surrounding areas to protect from contamination and deterioration. If paint system comprises more than one coat, each coat shall be stepped 30 mm back from the edge of the preceding coat and away from masked areas. Immediately before bolting, masking shall be removed. Faying surfaces shall be checked as free from adhesive, and cleaned with solvent if necessary. After final tightening of bolts, and inspection of joints: o o o o

•

Uncoated areas including bolts shall be thoroughly degreased and cleaned. Primer shall be applied without delay. The full shop coating specification shall be applied. 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’s recommendations. Page 9

o The load indicator protrusions should be oriented against the bolt head o 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 Indicator Fitting Under Bolt Head Black Finish Bolts All plating

2.4

BS 4395 Metric Series General Grade Part 1 Higher Grade Part 2 0.4 mm Max 0.5 mm Min 0.4 mm 0.4 mm Max 0.5 mm Min 0.4 mm

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

2.5

Cutting • •

2.6

Flame-cut edges which are free from significant irregularities shall be accepted without further treatment except for the removal of dross; otherwise cut edges shall be dressed to remove irregularities. Sniping of stiffeners at the root radii of rolled members shall be avoided wherever possible. 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.

Drilling Bolt holes shall be drilled, punching is not allowed. Slotted holes shall be formed by drilling two holes and completed by cutting. Holes in components shall be shown to the following 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 a bolt, whose adjustment may cause it to be out of perpendicular, can be accommodated through the base plate. Where cope holes are required to allow completion of butt welding they shall be of adequate size to allow fillet welding to seal the connection, while still allowing full accessibility 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 damage components it passes through and adequate return earth connections are made local to the area being welded. Welding shall not be permitted during inclement weather, unless adequate protective measures are taken.

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2.7.2

Welders • •

• • • 2.7.3

Welding Methods • • • • • • •

2.7.4

Welders employed on the work shall be tested to BS EN 287: Part 1 and Part 2, but in the case of welders engaged on fillet welding only, BS 4872: Part 1 is an acceptable alternative. Welder testing shall be witnessed and certificates endorsed by an independent Inspection 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 position and type of weld proposed. Welding shall be carried out under the supervision of a competent welding technologist and the test pieces shall be tested in accordance with BS EN ISO 15614: Part 1. Documentation shall be maintained to enable welds to be traced to the welder who made them. The Engineer has the right to instruct the Contractor to suspend any welder whose performance is deemed unsatisfactory.

Welding of steels to BS EN 10025 and BS EN 10210: Part 1 shall be metal arc process 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 m or length of weld, whichever is smaller) and 2 mm maximum. Butt welds shall be full penetration welds. Butt welds in flanges and webs shall be dressed flush by grinding in the direction of stress. Run-on/run-off plates shall be used during butt welding. No temporary backing strips shall be permitted. Penning of welds will not be permitted. Welding electrodes shall be of matching chemical composition to the parent metal in compliance with BS EN ISO 2560, and shall give a weld deposit with mechanical properties not less than the minimum specified for the parent metal. Hydrogen-controlled electrodes shall be used for butt welding of steel over 25 mm thick.

Weld Testing Finished welds shall comply with Section 6 of API Standard 1104. Defective welds shall be cut out, remade and retested until approved. For surface flaw examination, magnetic particle inspection (MPI) shall be used. If MPI is impractical, dye penetrant inspection (DPI) can be used in accordance with the recommendation 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 accepted standard which is generally suitable for structural steelwork. The Engineer shall check that any additional project specific requirements for non-destructive testing (NDT) of welds are clearly specified in the Particular Specification. BS 5950: Part 2, Annex A may be 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 970 over the full length of all welds. Such inspection shall be performed before any required NDT inspection. A suitably qualified person for visual inspection of welds may be a welding inspector or a welder who can provide evidence of having been trained and assessed for competence in visual inspection of the relevant types of welds. Page 11

2.7.6

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

2.8

Composite Floors

2.8.1

Stud Welding • • • • •

•

2.8.2

Decking • • •

• • • • • 2.8.3

Shear studs shall be through deck welded on site following erection of the profiled steel decking. Top surfaces of beam flange shall be free from mill-scale, rust, grease, oil, paint, and other substances detrimental to welding. Flanges shall be cleaned prior to laying decking. 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 shall be 25 mm. Before starting, suitability of materials, equipment and welding system proposed for welding of studs shall be demonstrated. Not less than ten studs shall be fixed for testing. 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. Test results shall be retained for the Engineer’s inspection. Production welds shall be visually free from cracks and lack of fusion and capable of developing at least the nominal ultimate strength of the studs. 2% of all studs shall be bent to 15 degrees to the vertical, to ensure continuing weld adequacy. Bent studs are not required to be re-straightened.

Floor decking shall be fixed (during layout) to the beams to ensure no gaps between beams 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 steel beams. After fixing, access to the decking shall be via crawling boards. Any damaged sheeting shall be replaced entirely at the Contractors expense. Delays in delivery of new sheets will not be considered as grounds for an extension of the contract period. The Contractor shall ensure that no moisture is trapped between the beams and decking, and provisions shall be made for boiling off any moisture prior to studwelding. Joints in the decking shall be prepared to the manufacturer' s recommendations (by taping or mechanical fixing) to prevent grout leakage. Decking sheets are to be clean and free of all traces of grease or mould oil contamination. The Contractor shall de-grease the decking to the satisfaction of the Engineer. Spacers for reinforcement shall be steel or concrete, in accordance with the Concrete Specification. The use of plastic spacers is not permitted. All ferrules shall be removed prior to placing the reinforcement or concrete.

Temporary Propping • •

All propping for concrete work shall comply with the Concrete Specification. Where required by the design the Contractor shall provide, install and maintain propping of all slabs as required until the design strength of the concrete has been reached. Propping shall be in accordance with the deck suppliers’ recommendations and shall be capable of transferring all loads to the ground or floors below without overstressing any part of the structure. A full method statement shall be submitted and approval shall be obtained from the Engineer before installation. Page 12

•

Propping shall not be removed until the concrete in the slabs has achieved the design strength. The propping shall be progressively lowered in bays between columns to ensure the loads taken by the propping are transferred uniformly to the composite construction.

2.9

Foundations

2.9.1

Holding Down Bolts • • • • •

2.9.2

The Contractor shall position the holding down bolts and sleeves in accordance with the Contractor' s Foundation Plan. The ends of bolts shall be held and linked by cast steel sections. Holding down bolts shall be protected by bituminous paint to the unthreaded parts before casting in, and all exposed parts and nuts shall be recoated after grouting and tightening. 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 by the Engineer. Bolts shall be cast into foundations, using templates to ensure accurate positioning to the required line and level, within cylindrical pockets (sleeves). Anchor plates shall incorporate welded ' stops'to prevent bolt rotation during tightening. Neither bolts nor pockets shall be in contact with steel reinforcing bars. Immediately after concreting in, all bolts shall be ' waggled'to ensure free movement within the pocket.

Grouting • • • • • •

All grout and grouting shall comply with the Concrete Specification. The Contractor shall notify the Engineer if the space beneath any column base is less than 15 mm or more than 50 mm, and await his instructions before grouting under 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 and finally 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 location shall be provided. o In all cases a shrinkage compensating additive shall be incorporated in the material in accordance with manufacturer' s recommendations.

•

2.10

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.

Contractor’s Responsibilities •

The Contractor shall inspect the prepared foundations and holding down bolts for position and level not less than seven days before erection of steelwork starts. In the event of any discrepancies found which are outside the permitted maximum deviations, these shall be reported to the Engineer and the necessary remedial work shall be carried out before erection commences.

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• •

Accuracy of position and levels of foundations and holding down bolts shall be as specified in the National Structural Steelwork Specification for Building Construction. It should be noted in particular that the permitted deviations for foundations and foundation 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 is 20 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 well as construction allowance. Note also the required bolt movement in the location tube of 25 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 an agreed time period prior to erection including the details of lifting plant and other machinery. 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 lines and datum levels within or immediately adjacent to the Works. Before grouting under column bases (or casting-in bases) the Contractor shall check the accuracy of the steelwork erection and any errors shall be corrected. The Contractor shall • •

• •

Achieve the design level of base plates during erection of columns, and steel plate packs or shims of appropriate thickness shall be used. It is not allowed to support base plates from levelling nuts. Be entirely responsible for stability of the steelwork during erection and shall arrange for all temporary guying, bracing and supports, together with any additional tackbolts necessary for structure stability until final bolting up. Use of tack welds shall be limited to an indispensable minimum. Assemble all parts as shown on the drawings and shall accurately position, plumbline and level the work. Drift pins shall only be employed to align component parts and must not distort the work. Accurately erect the steelwork within the tolerances outlined in National Structural Steelwork Specification and BS 5950: Part 1. In the event of discrepancy, the following 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 and number shall be as specified in the contract. Page 14

3.

PART 3 SUMMARY

3.1

Codes of Practice Reference

Title

BS 4: Part 1

Structural steel sections. Specification for hot-rolled sections Steel plate, sheet and strip. Carbon and carbonmanganese plate, sheet and strip Specification for continuously hot-dip zinc coated and ironzinc alloy coated steel Specification for hot-dip zinc coated and hot-dip aluminium/zinc coated corrugated steel sheets for general purposes ISO metric precision hexagon bolts, screws and nuts. Specification ISO metric precision hexagon bolts, screws and nuts. Specification Specification for metal washers for general engineering purposes. Metric series Specification for high strength friction grip bolts and associated nuts and washers for structural engineering. General grade Specification for high strength friction grip bolts and associated nuts and washers for structural engineering. Higher grade bolts and nuts and general grade washers Specification for the use of high strength friction grip bolts in structural steelwork. Metric series. General grade Specification for the use of high strength friction grip bolts in structural steelwork. Metric series. Higher grade (parallel shank) Specification for approval testing of welders when welding procedure approval is not required. Fusion welding of steel Specification for sherardized coatings on iron or steel. Specification for ISO metric black cup and countersunk head bolts and screws with hexagon nuts Structural use of steelwork in building Specification for holding down bolts Wrought steels for mechanical and allied engineering purposes. Requirements for carbon, carbon manganese and alloy hot worked or cold finished steels Qualification test of welders. Fusion welding. Steels Approval testing of welders for fusion welding. Aluminium and aluminium alloys Non-destructive testing. Penetrant testing. General principles Welding consumables. Solid wires, solid wire-flux and tubular cored electrode-flux combinations for submerged arc welding of non alloy and fine grain steels. Classification Welding consumables. Covered electrodes for manual metal arc welding of high strength steels. Classification Welding consumables. Fluxes for submerged arc welding. Classification Non-destructive examination of fusion welds. Visual examination Welding. Recommendations for welding of metallic materials. General guidance for arc welding Tensile testing of metallic materials. Method of test at ambient temperature

BS 1449: Part 1 BS 2989 BS 3083 BS 3692 BS 4190 BS 4320 BS 4395: Part 1 BS 4395: Part 2 BS 4604: Part 1 BS 4604: Part 2 BS 4872: Part 1 BS 4921 BS 4933 BS 5950 BS 7419 PD 970 BS EN 287: Part 1 BS EN 287: Part 2 BS EN 571: Part 1 BS EN 756 BS EN 757 BS EN 760 BS EN 970 BS EN 1011: Part 1 BS EN 10002: Part 1

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BS EN 10025 BS EN 10029 BS EN 10056 BS EN 10143 BS EN 10160 BS EN 10162 BS EN 10163 BS EN 10210: Part 1 BS EN 10210: Part 2 BS EN 10219: Part 1 BS EN 10219: Part 2 BS EN ISO 1461 BS EN ISO 2320 BS EN ISO 2560 BS EN ISO 3506 BS EN ISO 7042 BS EN ISO 7719 BS EN ISO 8501: Part 1

BS EN ISO 11124 BS EN ISO 12944 BS EN ISO 14341 BS EN ISO 14713 BS EN ISO 15614: Part 1

3.2

Hot rolled products of structural steels Tolerances on dimensions, shape and mass for hot rolled steel plates 3 mm thick or above Specification for structural steel equal and unequal leg angles Continuously hot-dip metal coated steel sheet and strip tolerances on dimensions and shape Ultrasonic testing of steel flat product of thickness equal or greater than 6 mm (reflection method) Cold rolled steel sections. Technical delivery conditions. Dimensional and cross-sectional tolerances Delivery requirements for surface condition of hot-rolled steel plates, wide flats and sections Hot finished structural hollow sections of non-alloy and fine grain steels. Technical delivery requirements Hot finished structural hollow sections of non-alloy and fine grain steels. Tolerances, dimensions and sectional properties Cold formed welded structural hollow sections of non-alloy and fine grain steels. Technical delivery requirements Cold formed welded structural hollow sections of non-alloy and fine grain steels. Tolerances, dimensions and sectional properties Hot dip galvanized coatings on fabricated iron and steel articles. Specifications and test methods. Prevailing torque type steel hexagon nuts. Mechanical and performance properties Welding consumables. Covered electrodes for manual metal arc welding of non-alloy and fine grain steels. Classification Mechanical properties of corrosion-resistant stainless-steel fasteners Prevailing torque type all-metal hexagon nuts. Property classes 5, 8, 10 and 12 Prevailing torque type all-metal hexagon nuts, style 1. Property classes 5, 8 and 10 Preparation of steel substrates before application of paints and related products. Visual assessment of surface cleanliness. Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings Preparation of steel substrates before application of paints and related products Paints and varnishes. Corrosion protection of steel structures by protective paint systems Welding consumables. Wire electrodes and deposits for gas shielded metal arc welding of non alloy and fine grain steels. Classification Protection against corrosion of iron and steel in structures. zinc and aluminium coatings. Guidelines Specification and qualification of welding procedures for metallic materials

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

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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 Practice for Painting of Buildings’, BS EN 12944 ‘Paints and varnishes. Corrosion protection of steel structures by protective paint systems’, BS 7079 ‘Preparation of Steel Substrates Before 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 from those of the approved manufacturer, the manufacturer' s requirements shall take precedence, subject to the approval of the Engineer. All references to Standards and Codes of Practice shall be made to the editions current at 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 similar to Bahrain. The upper and lower limits provided for the Nominal Dry Film Thickness (NDFT) indicate the minimum requirements for time to first maintenance of 10 years and 15 years respectively. Where an upper limit is not provided, the time to first maintenance is expected 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 volatile organic 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 systems listed in Table 2 below: Note: Decorative paint coatings shall only be applied to steel intended to be installed in air-conditioned environments. Table 2 – Coating System for Decorative Coating System ID System 1 System 2 System 3

4.1.1.3

Primer Alkyd Acrylic Epoxy

Topcoat Alkyd Acrylic Poly-urethane

NDFT m 80-160 120-160 120-160

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

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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 in urban areas. Table 3 – Coating System for Protective Coating – Exposure Class E1 System ID System 1 System 2 System 3 System 4

Primer Alkyd Acrylic Epoxy Epoxy

Topcoat Alkyd Acrylic Epoxy Poly-urethane

NDFT m 160-200 160-240 160-240 160-240

Exposure condition E2 shall apply to the exteriors of buildings in urban areas greater than 1,000 m from the coast and the interior of buildings containing swimming pools, or chemical processing facilities. Table 4 – Coating Systems – Exposure Class E2 System ID System 1 System 2 System 3 System 4

Primer Acrylic Epoxy Epoxy-Zn-R Ethyl-silicate Zn-R

Topcoat Acrylic Poly-urethane Poly-urethane Poly-urethane

NDFT m 240 240-320 200-320 200-320

Exposure condition E3 shall apply to the exteriors of all buildings less than 1,000 m from the coast and the interior of buildings containing almost permanent condensation or high pollution levels. Minimum coating thickness shall be as in Table 5 below: Systems denoted by * shall only be applicable to applications where UV exposure is not expected. Table 5 – Coating Systems – Exposure Class E3 System 1* System 2* System 3* System 3 System 4 System 5 4.1.1.4

Primer Epoxy EpoxyZn-R Ethylsilicate Epoxy-Zn-R Ethyl-silicate Epoxy Zn-R

Topcoat Epoxy

NDFT m 400 300-500

Epoxy

240-320

Poly-urethane Poly-urethane Epoxysiloxane

240-320 240-320 200

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 of buildings or interior spaces where the exposure condition is E1 – as defined above – shall be in Table 6 below: Page 18

Table 6 – Galvanized Coating System – Exposure Class E1 Article Thickness 6 mm 3 mm to < 6 mm 1.5 mm to < 3 mm < 1.5 mm

Mean coating thickness m 85 70 55 45

The minimum coating thickness for exterior steelwork where the exposure condition is E2 – as defined above – shall be as in Table 7 below: Table 7 – Galvanized Coating System – Exposure Class E2 Article Thickness 6 mm

Mean coating thickness m 85

The minimum coating thickness for exterior steelwork where the exposure condition is E3 – as defined above – shall be as in Table 8 below: Table 8 – Galvanized Coating System – Exposure Class E3 Article Thickness 6 mm 3 mm to < 6 mm 1.5 mm to < 3 mm 4.1.1.5

Mean coating thickness m 115 95 70

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 in Table 9 below. Table 9 – Fire Protection Coating System System ID System 1 System 2 System 3 System 4 System 5

Primer Ethyl silicate Zn-R Epoxy Zn-R Ethyl silicate Zn-R or Epoxy Zn-R Ethyl silicate Zn-R or Epoxy Zn-R Ethyl silicate Zn-R or Epoxy Zn-R

Fire Protection Coating 1 Thin film intumescent Intumescent epoxy mastic 2 Lightweight concrete Fire protection boards/ casings3 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 unless approved by the Engineer 2 Lightweight concretes shall generally comply with the Concrete Specification and shall be proprietary mixes based on vermiculite or similar lightweight materials with a proven fire rating when tested in accordance with BS 476 3 Due to longer-term durability issues, fire-protection systems based on protection boards or casings shall be applicable for internal applications only 4 Concrete shall comply with the Concrete Specification and shall provide a minimum cover of 50 mm to the element it is protecting. Where installation is external, the

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concrete shall be coated with a protective coating rated to Class 1 for flame spread when 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 the Engineer. Submittals shall include: •

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

•

nominal recommended coating thickness surface preparation requirements manufacturer approved application methods available colours over-coating intervals

Samples of the proposed coating system o A verifiable track record for the coating system for use in climates similar to Bahrain.

For fire rated systems, test certificates indicating the performance of the material when testing 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 not relieve 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. Alternative systems shall meet the durability requirements of the approved systems. Their performance shall be documented and evidence shall be submitted for approval by the Client.

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 and control 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 the safe handling, and storage or materials. •

Control of Volatile Organic Compounds Materials shall be stored, prepared and applied in well ventilated areas. Where adequate ventilation is not practically achievable, painters shall be provided with suitable respiratory devices to prevent ingestion of vapours.

•

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

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Fire hazards shall be assessed and controls defined in the Contractor’s method statements. 4.1.3.2

Storage All materials shall be stored in a secure air-conditioned area. Unless other temperatures are 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 be taken to site as required by planned coating operations. Containers shall remain sealed until the contents are prepared for use. Partly used containers may be re-sealed and used later unless otherwise advised by the manufacturer. Partly used containers shall be clearly marked. Steelwork protected by only prefabrication primer shall not be stored outside for more than 21 days. If damage has exposed parent metal, local re-blasting may be required to prepare the steel for remedial coating. The maximum time lag between cleaning steel and applying primer 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 discarded irrespective of its apparent condition. Labelling and date stamps: All containers shall be clearly identifiable and shall be machine labelled with the following information: o o o o o o o o

Manufacturer’s name Material name Mass/Volume of contents of container Date of Manufacture Expiry date or expected shelf life Batch and/or production number Material’s hazard classification (if applicable) 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. The submittal shall include but not be limited to the following: o Technical data sheets and material safety data sheets (MSDS) for all products proposed o Details of proposed surface preparation methods and materials o Details of proposed application methods o Details of equipment to be used o Details of Personal Protective Equipment required o Details of safe handling controls o Methods for protecting finished coatings during transport and erection on site o Details of fire safety controls o Nominated safety officers Page 21

•

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

4.1.4.2

Preparation •

Cleaning Accumulated dirt, grease and soluble salts shall be removed and the steelwork cleaned in accordance with BS 7079. Dry bristle brushing shall normally be adequate for accumulated dirt. Soluble salts shall be removed by fresh water washing.

•

Preparation of Welds/Edges Sharp edges shall be rounded or chamfered. All burrs from holes shall be removed prior to blasting. All welds shall be free of undercutting, craters and splatters. Splatters shall be removed 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 the coating manufacturer. For galvanized elements, the surface shall be prepared by sweep blast, cleaned to surface 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 oil free compressed air and brush. Freedom from residual surface contamination shall be checked by pressing the adhesive side of transparent adhesive tape onto the cleaned 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 other protective films prior to hot dip galvanizing.

•

Safety Personnel involved in surface preparation shall be trained to a recognized standard and shall wear the appropriate Personal Protective Equipment that shall include but not be limited to: o Eye protection o Hearing protection o Respiratory protection Areas where surface preparation works are carried out shall be clearly demarcated with warning signs/barriers. Access to the work site during surface preparation shall be limited to those carrying out the works.

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Access to the work site for other personnel shall only be upon a clearly defined signal 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 minimum that is practically achievable. Where periods between surface preparation and coating may be sufficient for the preparation grade to change (e.g. by formation of rust), temporary protection such as pre-fabrication primers or adhesive films shall be provided. 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 in accordance 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 molten zinc. Components shall be immersed in the bath only for a period sufficient to attain the temperature of the bath, and shall be withdrawn at a speed which ensures that 2 the coating of 610 g/m of surface is achieved (85 microns minimum DFT). Components shall be covered evenly on all surfaces and shall be free from pin holes, lumps of galvanizing materials and all other defects. Items described as heavily galvanized shall be grit blasted prior to galvanizing and shall receive a minimum coating of 1,000 g/m2 of surface (140 microns minimum DFT). Before application of the specified paint treatment, galvanized steelwork shall be cleaned, degreased and etch primed. All damaged galvanizing surfaces and all edges exposed by cutting, drilling or welding after galvanizing shall be treated with two coats of sprayed metallic zinc in accordance with manufacturer specification, prior to restoring of paint system. Contact between galvanized steel members and aluminium surfaces or between galvanized and ungalvanized steel members shall be prevented by means of approved 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 the manufacturer’s recommendations. 4.1.5.2

Safety Personnel involved in surface preparation shall be trained to a recognized standard and shall wear the appropriate Personal Protective Equipment that shall include but not be limited to: • • • •

Eye protection Hearing protection (as applicable) Skin protection (gloves or barrier cream as appropriate) Respiratory protection Page 23

4.1.5.3

Shop Coating Where fabrication methods allow, all coating shall be completed in a dedicated coating facility. All completed coatings shall be protected from damage during storage and during transport to the site.

4.1.5.4

Site Coating Where fabrication methods do not allow shop coating or where touch-ups or final coats on connections are required, site coating shall be allowed. Containment shall be provided to ensure abrasive used for blast cleaning and coating overspray is contained local to the works. The containment shall also offer the area of any works adequate protection from rain and wind. Ideally the containment should be able to control the local environment to the ambient conditions detailed in this specification throughout the preparation and painting operations 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 and clement 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 can occur during the initial drying period of the coating When the amount of moisture likely to be deposited on the surface by condensation or 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 be measured using a surface temperature thermometer and the dew point calculated after measurement of humidity with a hygrometer. Coating application should not take place when 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 the manufacturer’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 is obviously thickening. Page 24

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 the Concrete 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’s recommendations and any other factors that may affect the suitability of a particular method. The application method shall be included in the method statement submittal for review by the Engineer. All application equipment shall be cleaned at the commencement of painting and shall be kept 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 the completed coating system must meet the minimum dry film thickness defined in the project specification. Unless agreed otherwise, individual dry film thicknesses of less than 80% of the nominal dry 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 prove difficult resulting in low dry film thicknesses. Wet film thickness gauges shall be used regularly to check adequate wet material is applied 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 comb gauge used in accordance with BS EN ISO 2808. After each coat has dried, check total accumulated film thickness using a magnetic or electromagnetic meter. Average dry film thickness shall be at least specified thickness over any square metre and 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. Page 25

Measurements to be independently witnessed. Check meter against standard shims and recalibrate regularly against a smooth steel reference 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 the manufacturer. 4.1.5.12 Colour of Coats To enable clear identification of coats, the primer, intermediate and top coats shall be of different 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 warranty period. 4.1.5.13 Special Requirements •

Connections: Where fabricated items are to be subsequently welded on site, the coating system shall not be applied within 150 mm of the weld. Where steelwork is galvanized, the galvanizing shall be removed from the weld area to 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 affect the ability of the connection to perform as designed. Friction type bolted connections shall be blast cleaned to Sa 2½ in accordance with ISO 8501: Part 1 with an agreed roughness. The friction surfaces can be coated with a 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 the contract 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 the contract documents. Where localised repairs are required, the coating shall be made good by local cuttingback of the coating, preparation of the surface and re-application of the coating system in accordance with the contract documents. 4.1.6

Reference Documents

4.1.6.1

Standards Reference

Title

BS 476 BS 5950 BS 6150

Fire tests on building materials and structures The structural use of steelwork in buildings Painting of buildings. Code of practice Page 26

BS 7079 BS EN ISO 1461 BS EN ISO 2808 BS EN ISO 8501 BS EN ISO 8502 BS EN ISO 8503 BS EN ISO 8504 BS EN ISO 9002 BS EN ISO 12944 BS EN ISO 14713

4.1.6.2

General introduction to standards for preparation of steel substrates before application of paints and related products Hot dip galvanized coatings on fabricated iron and steel articles. Specifications and test methods Paints and varnishes. Determination of film thickness Preparation of steel substrates before application of paints and related products. Visual assessment of surface cleanliness Preparation of steel substrates before application of paints and related products. Tests for the assessment of surface cleanliness Preparation of steel substrates before application of paints and related products. Surface roughness characteristics of blast-cleaned steel substrates Preparation of steel substrates before application of paints and related products. Surface preparation methods Quality systems. Model for quality assurance in production, installation and servicing All parts Paints and varnishes. Corrosion protection of steel structures by protective paint systems Protection against corrosion of iron and steel in structures. Zinc and aluminium coatings. Guidelines

Publications rd

Fire protection for structural steel in buildings, 3 Edition, (2004), Association for Specialist Fire Protection, UK ISBN 1 870409 22 1 Spray coatings for the protection of structural steel – Part 1: Technical guidance note for the mechanical retention of sprayed mineral coatings based upon the requirements of BS 8202: Part 1: 1993, Association for Specialist Fire Protection, UK ISBN 1 870409 11 6

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Abbreviations Air Circuit Breakers Approved Code of Practice Air Conditioning and Refrigeration Industry Board Acoustic Doppler Current Meters ADCM AFMA Australian Fisheries Management Authority AGMA American Gear Manufacturers’ Association AISI American Iron and Steel Institute AS Acceptance Strength ASTA Association of Short-circuit Testing Authorities American Society for Testing Materials ASTM ATS Automatic Transfer Switch American Welding Society AWS BASEC British Approval Service for Electric Cables Building Officials and Code Administrators BOCA BRE Building Research Establishment Ltd. British Standards BS Building Service Research and Information BSRIA Association California Bearing Ratio CBR CCTV Close Circuit Television CECOMAF Comité Européen des Constructeurs de Matériel Frigorifique CENELEC Comité Européen de Normalisation Electrotechnique CFC Chlorofluorocarbons CIBSE Chartered Institution of Building Services Engineers CHW Chilled Water CI Cast Iron CLW Cooling Water CM Current Margin / Communication cable Communication cable (Plenum) CMP Code of Practice CP CPC Circuit Protection Conductor CPT Cone Penetration Testing Categorised Required Strength CRS Cathode Ray Tube CRT CRZ Capillary Rise Zone CT Current Transformer Underwriters Laboratories Incorporated c(UL) (Canada) DEO Defence Estate Organisation DFT Dry Film Thickness DI Ductile Iron DIN Deutsches Institut für Normung DPC Damp Proof Course DPDT Differential Pressure, Differential Temperature DS Durability Strength DVR Digital Video Recorder DW Ductwork Specification EA Exhaust Air ECMA European Computer Manufacturers Association Exhaust Air EA ECMA European Computer Manufacturers Association ECR Extra Chemical Resistant EIA Environmental Impact Assessment/ Electronic Industries Alliance ACB ACOP ACRIB

EMC EPDM FA FBA FRP FSC GANA GGBS GMS GRC GRP HCFC HDPE HEPA HFC HPL HPPE HRC HSE HSFG HV HVCA ICBO IGCC IGE/UP IP ISAT ISO ITP KD kVA LCD LED LPG LS0H LSF LV MCB MCC MCCB MDF MDD MDPE MEP MICC MIO MMI MOD MS MSDS MSRPC N NDFT NEMA NFPA NRC NS

Electromagnetic Compatibility Ethylene-propylene-diene-monomer copolymer Fresh Air Factory Built Assembly Fibre Reinforced Polymer Forest Stewardship Council Glass Association of North America Ground Granulated Blast-furnace Slag Galvanized Mild Steel Glass Reinforced Cement/Glass Reinforced Concrete Glass Reinforced Plastics Hydrofluorocarbons High Density Polyethylene High Efficiency Particulate Air HydroFluoroCarbon High Pressure Laminate Higher Performance Polyethylene High Rupturing Capacity Health and Safety Executive High Strength Friction Grip High Voltage Heating and Ventilating Contractors’ Association International Conference of Building Officials Insulating Glass Certification Council Institution of Gas Engineers – Utilization Procedures Ingress Protection Initial Surface Absorption Test International Standard Organization Inspection Testing Plan Kiln Dried Kilovolt Ampere Liquid Crystal Display Light Emitting Diode Liquid Petroleum Gas Low Smoke Zero Halogen Low Smoke and Fume Low Voltage Miniature Circuit Breaker Motor Control Centre Moulded Case Circuit Breakers Medium Density Fireboard Maximum Dry Density Medium Density Polyethylene Mechanical Electrical Plumbing Mineral Insulated Copper Covered Cable Micaceous Iron Oxide Man Machine Interface Ministry of Defence Micro-silica Material Safety Data Sheet Moderate Sulphate Resistance Portland Cement Nitrogen Nominal Dry Film Thickness National Electrical Manufacturers’ Association National Fire Protection Association Noise Reduction Coefficient Norwegian Standard

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O/D ODP OFS OFTEC O&M OPC PD PE PFA PFC PM PTFE PVC PVC-u PWTAG QA/QC RA RCCD RCD R&D REFCOM RPM RPZ RTD RTR SA SBCCI SDR SIS SP SPDT SRPC SS SSPC TIA TRA UL ULPA UP UPS UTP UV VC VR WBP W/C WIS WP WRAS XLPE

Outside Diameter Ozone Depletion Potential Oil Fired (Appliance/Equipment) Standard Oil Firing Technical Association Operation and Maintenance Ordinary Portland Cement Published Documents Polyethylene Pulverised Fuel Ash Power Factor Correction Project Manager Polytetrafluoroethylene Polyvinylchloride Unplasticised Polyvinylchloride Pool Water Treatment Advisory Group Quality Assurance/Quality Control Return/Recycled Air Residual Current Circuit Breaker Residual Current Device Research and Development Register of Companies Competent to handle refrigerants Reinforced Plastic Mortar Reduced Pressure Zone Resistant Temperature Detector Reinforced Thermosetting Resin Supply Air Southern Building Code Congress International (Incorporated) Standard Dimension Ratio Swedish Institute of Standards Super-plasticizing Single Pole Double Throw Sulphate Resistance Portland Cement Structural Strength Steel Structures Painting Council Telecommunication Industry Association Trussed Rafter Association Underwriters Laboratories Incorporated Ultra Low Penetration Air Unsaturated Polyester Resin Uninterruptible Power Supply Unshielded Twisted Pair Ultra Violet Vitrified Clay Video Recorder Weather and Boil Proof Water Cement Ratio Water Industry Specification Water Proofing Water Regulations Advisory Scheme Cross Linked Polyethylene

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