Coating Specification for New Exterior SteelworkSpecification RAP-NCC-0620

A generic specification for exterior coating system on atmospherically exposed carbon steel in low to moderate corrosivity zones for commercial new-build construction projects.

Purpose and ScopeThis Specification is intended as a supplement to the requirements of the Australian National Construction Code (NCC) and is provided to assist Owners in gaining suitable corrosion protection of new atmospherically exposed steel in a low to moderate corrosivity zone, typically at a distance greater than one kilometer from salt water.

This document sets out standard requirements to ensure that a high-quality level of workmanship and long-term performance is achieved.

This document refers to relevant Australian and International Standards. Any contradiction between this Manual and product supplier documentation should be referred to the Owner for resolution.

LimitationsThis document is a generic document specific to one coating system. An assessment should be made by the Coatings Focal Point (CFP, as defined in this document) as to whether the works are to be exposed to either:

Greater corrosivity by factors either environmental or introduced by abrasion, hidden in buried or submersed zones, or exposed by chemicals or pollution.

Different surfaces, such as Galvanized steel or previously painted steel.

If the CFP deems that the service environment requires differing or more robust protection than the PUR4 system described here, there shall be a project-specific specification developed.

The latest version of this document should be sourced from www.RemedyAP.com.au and the document considered uncontrolled when printed.

Remedy Asset Protection (Remedy AP) is available for support of condition assessment, coating selection, tender panel assessment, site inspection, or general inquiries.

ContentsPurpose and Scope............................................................................................................................................................................1Limitations.........................................................................................................................................................................................1Roles.................................................................................................................................................................................................. 3Coatings Focal Point.........................................................................................................................................................................3Independent Third-Party Coating Inspector...................................................................................................................................4Applicator Personnel...................................................................................................................................................................4Inspection Equipment and Personnel....................................................................................................................................4Pre-commencement Meeting..................................................................................................................................................5Coating Systems for External Steelwork (PUR4).........................................................................................................................5

Pre-fabrication works...................................................................................................................................................................5

Trial Application.............................................................................................................................................................................5

Surface Preparation........................................................................................................................................................................6Fabrication Defects......................................................................................................................................................................6

Power-tool Cleaning......................................................................................................................................................................6

Abrasive Blasting..........................................................................................................................................................................6

Blast Cleaning Equipment.......................................................................................................................................................7

Salt Contamination........................................................................................................................................................................7

Application.........................................................................................................................................................................................7Mixing Paint................................................................................................................................................................................7

Tinting...........................................................................................................................................................................................8

Conditions for Painting............................................................................................................................................................8

Application of Paint...................................................................................................................................................................8

Priming.........................................................................................................................................................................................8

Stripe Coating of Edges..............................................................................................................................................................8

Application..................................................................................................................................................................................9

Repair of Coating Defects..............................................................................................................................................................9

Quality...............................................................................................................................................................................................9Materials........................................................................................................................................................................................9

Documentation..............................................................................................................................................................................9

Reporting...................................................................................................................................................................................11

Warranty......................................................................................................................................................................................... 11Disclaimer........................................................................................................................................................................................11More Information............................................................................................................................................................................12RemedyAP....................................................................................................................................................................................... 12

Our Vision, Our People, Our Culture............................................................................................................................................12

RemedyAP CorrAssure™ Program................................................................................................................................................12

DocoPro...........................................................................................................................................................................................13

Roles The Owner described in this document is either

the Asset Owner or their nominated representative.

The Owner may nominate a Coatings Focal Point to oversee and validate the technical requirements of corrosion protection by protective coatings. The Coatings Focal Point shall be NACE Coating Inspector Program (CIP) Certified – Level 3.

The Contractor is considered to have overall responsibility for the site and sub-contractors.

The Applicator refers to the sub-contractor company that performs surface preparation and coating application tasks.

An independent third-party coating inspector may be nominated to represent the Owner during quality inspection Hold points.

Coatings Focal Point (Optional)RemedyAP has capability to be engaged to act as the Coatings Focal Point (CFP), or an inspector of equivalent experience and certified per NACE CIP Level 3 can be appointed by the Owner and be responsible for:

Review of project documentation Including:

i) Condition assessment of new or existing structure

ii) Assessment of corrosivity zoneiii) Recommendation for

project- specific specification (this document or other encompassing specification)

Assist the tender review panel in assessing the technical sections of the Applicator submissions.

Respond to technical queries raised in pre-start meetings and any other stage throughout the works.

Recommend Owner-initiated Hold points on the Inspection and Test Plan (ITP).

Review and approve Applicator ITPs and other quality documentation. This should occur at a frequency of:

i) Pre-start – to determine the suitability of document templates related to this Specification,

Owner

Architect

Coatings Focal Point

Independent Coating

Inspector

Contractor

Applicator

Coating Supplier

Coati

ng F

ocal

Poi

nt

Initial Review

Tender Review Panel

Project deviations

Salt Contamination

Power-tool cleaning

Quality Documentation

Review

Inspection and Test Plan - Hold Points

Review progress reports

Coating Inspection

Appoint coating inspector (if required)

Inspect Trial Application

ii) Progress payment stages – to ensure documentation is being completed and submitted at each stage of Applicator payment claim, and,

iii) Completion – to ensure final submission of documentation Provide recommendation if an independent third-party coating inspector is needed to represent

the Owner during inspection Hold points as described in the ITP.

Independent Third-Party Coating Inspector (Optional)The Owner may engage RemedyAP or the services of an equivalent independent third-party coating inspector to conduct testing during ITP Hold points to verify application conformance.

The Inspector shall be a qualified NACE CIP - Level 2.

Repairs to the coating at these test locations shall be at no incremental cost to the Owner.

The coating inspector shall be independently engaged by the Owner. However, should the Owner require the Contractor to engage the Inspector, the inspector shall:

a) Represent the interests of the Owner,b) Ensure compliance to this Specification

is maintained, andc) Be given approval to refer

non-conformances to this Specification to the Owner.

The Inspector shall provide inspection oversight for initial surface preparation and environmental conditions, surface application, conformance testing, and documentation (as required under each section of this Specification). The Inspector may elect to perform additional inspections where observation indicates a lack of conformance by the Applicator.

The Inspector shall be notified with a minimum of 48 hours of prior notice. For works planned significantly in advance, 2 weeks of prior notice is recommended for scheduling and resourcing purposes.

Applicator PersonnelAll surface preparation and painting shall be undertaken under the supervision of an experienced supervisor, with the following accreditation:

Certificate III in surface finishing (Metal Trades), or, A NACE CIP - Level 1 Inspector, or, Other scheme approved by the Australasian Corrosion Association (www.corrosion.com.au).

Furthermore, preference should be given to Applicator Companies that are accredited to Protective Coatings Certification Program (PCCP). See: http://apas.gov.au/ .

Inde

pend

ent t

hird

-par

ty

coati

ng in

spec

tor

Inspect trial application

Inspect surface preparation

Inspect pre-fabrication coatings

Inspect each coating layer

Inspection Equipment and PersonnelThe Applicator shall provide all equipment necessary to accurately measure relative humidity and steel surface temperatures, wet and dry film thicknesses, and chloride levels. The Applicator shall be responsible for the calibration and maintenance of all measuring and inspection equipment and ensure that personnel are trained in their proper use.

The Owner may employ an independent third-party inspector to audit and verify the results from the Applicator’s inspector.

Pre-commencement MeetingBefore work commences, a meeting shall be held between the Owner, CFP, Contractor, Applicator, Coating manufacturer, and any subcontractors to clarify and concur with the Applicator’s proposed program, methodology, and inspection procedures. The Applicator shall submit his ITP and Program to the Owner one week prior to the scheduled date of this meeting.

Coating Systems for External Steelwork (PUR4)All exterior steel work shall be coated with the system designated in AS/NZS 2312 as PUR4. Surface preparation shall be by abrasive blast cleaning to Sa 2½ as specified in AS1627.4. Cleaned surfaces shall be primed with an epoxy zinc-rich primer conforming to AS/NZS 3750.9 Type 2 to give a nominal dry film thickness (DFT) of 75 to 90 microns. When cured, primed surfaces shall receive a build coat of high-build epoxy conforming to AS/NZS 3750.14, to give a nominal DFT of 125 to 175 microns. The final coat shall be a nominal 50 to 85 microns DFT of a recoatable 2-pack polyurethane conforming to AS/NZS 3750.6 and in a colour and gloss level per Owner concurrence. Total nominal DFT of the full coating system shall be 250 to 350 microns. Provision is made in Table 1 for individual readings that may be up to either +/- 20% of the nominated range, however, the average reading must comply.

Pre-fabrication worksThe Owner’s preference is for all pre-fabricated steel to be prepared with at least the approved primer coat applied in a suitable workshop environment prior to delivery to site.

Any holding primer applied shall be completely removed and surfaces shall meet the surface preparation requirements prior to application of the approved coating system. Where the approved primer is used as a pre-fabrication primer prior to installation, all surfaces shall be washed prior to over-coating in the field to remove all zinc salts by a method designated in AS 1627 Part 1. The manufacturer stated maximum re-coat window shall be halved for all pre-fabrication coatings once delivered to the field. Additionally, a maximum of a 3 month duration shall be applicable to coatings where no maximum value is stated.

All pre-fabrication coatings shall be subject to this specification including quality auditing, documentation, and inspection at the blast yard.

The Contractor shall ensure that the items are stored, handled, and shipped in a manner as to minimize damage. Soft packing shall be placed between the items and they shall not be stacked on top of one another. Any slings used for lifting shall be cushioned to prevent coating damage. Any damage shall be repaired according to this Specification.

Trial ApplicationA trial application shall be made on a piece of steel or on a sample plate of minimum dimensions, 300 x 300 x 6 mm steel. The trial shall include proposed methods of surface cleaning, surface restoration, coating application, and acceptance testing. The trial application will provide an expectation of coating surface texture and colour.

If it becomes apparent during the trial that adjustments are required to the proposed products, equipment, or work methods, the adjustments shall be submitted for approval prior to commencing the full work.

The Contractor shall seek approval for the supplied trial sample by the Owner. Once approved the trial application shall be the agreed upon reference sample when evaluating the full work.

Surface PreparationSurface preparation shall be preceded by washing down all steel surfaces by solvent cleaning to remove all surface contamination. Surface contamination is deemed to include chloride salts, bird droppings, algae or fungal growth, oil, grease, dirt, deteriorated and loose paint, loose scale, corrosion products, and any other materials that may reduce coating adhesion.

Potable water shall be used, and a biodegradable non-ionic detergent may be used to assist with removing surface contaminants such as salts, oil, and grease. The treated surface shall be washed down with a clean water rinse to remove detergents. Alternatively, oil and grease may be removed by solvent cleaning in accordance with AS 1627.1.

Heavy deposits shall first be removed by chipping, scraping, or impact tools. Sharp edges and corners shall be rounded with a suitable grinder to a minimum radius of 2 mm.

The degree of preparation shall be such that all loose matter, contamination, and deteriorated paint is removed from the surface.

Abrasive blast cleaning shall be used as the preferred method of surface preparation.

Abrasive blasting shall comply with the requirements of AS 1627.4, Sa 2 ½.

Fabrication DefectsBefore any weld areas are blast cleaned, they shall have all weld spatter, sharp corners, and hardened cut edges removed. The areas shall then be thoroughly scrubbed with clean water to remove all traces of weld fluxes. Edges and corners shall be rounded to a minimum radius of 2 mm.

Power-tool CleaningPower-tool cleaning may be suitable for either spot repair less than 0.5 m2 in area, site weld zones between two prefinished steel members, or where abrasive blasting is not allowed.

The preferred method shall be a finished surface using a bristle blaster.

If bristle blasting is approved, the surface shall be prepared to a cleanliness level at least the equivalent of AS1627.4, Sa 2. SSPC SP-15 is also a suitable Standard for use.

FIGURE 1 - POWER-TOOL CLEANING REQUIREMENT

For larger areas, substituting abrasive blast cleaning for power-tool cleaning has potential for negative consequences and therefore requires input from the CFP to recommend a project specific specification.

Abrasive BlastingAbrasive materials shall be garnet and shall comply with AS 1627.4. Materials shall be free from contamination and contain less than 100 mg/kg (equal to 100 ppm) chlorides and less than 0.3% copper.

The profile shall be of an angular and dense nature over the entire surface to be coated, as follows:

Abrasive blasting – between 40μm and 75μm, Bristle blasting – greater than 25µm.

Profile shall be measured with profile replicating tape in accordance with Method A of AS 3894.5 or other approved method.

If non-compliant readings are observed, additional testing shall be required to identify incompatible areas and rectified by:

Low readings – shall be rectified by additional blasting to increase the profile as per requirements of this Specification.

High readings – shall either be endorsed by the Coating supplier or the Applicator to provide detail on their preferred repair procedure and supply a field test for approval of the CFP prior to full scale rectification.

Adjacent sections of steel that either are not being refurbished or have already been completed shall be covered during abrasive blasting to protect from contamination or damage.

The Owner shall be notified for inspection each day when surface preparation is ready and prior to primer application.

Blast Cleaning EquipmentThe compressed air supply used for blasting shall be free of water and oil as determined by AS/NZS 3894.6. Adequate separators and traps shall be provided, and these shall be regularly emptied of water and oil. Accumulations of oil and moisture shall be removed from the air receiver by regular purging.

Salt ContaminationAt the Owner’s request, or where there is a risk of salt contamination or if the freshly blasted surface shows patches of discoloration of black or brown rust within an hour of blasting, the CFP shall be informed and will provide recommendations. Salt contamination, if identified, must be removed by the Applicator.

ApplicationPaint shall comply with the requirements of the relevant material and performance specification as listed below;

TABLE 1 - AS/NZS 2312.1 PUR 4 COATING SYSTEM

Generic Type Dry Film Thickness (µm) Standard APASMinimum Average Range Maximum

Zinc Rich Epoxy (ZRE)

60 75 90 110 AS/NZS 3750.9/2 2916HB Epoxy (HBE)

100 125 175 210 AS/NZS 3750.14 2973Polyurethane (PU)

40 50 85 100 AS/NZS 3750.6 2911 Totals (TDFT) 200 250 350 420

If deviation from these values is sought, a request must be submitted to the CFP who will provide appropriate parameters.

Mixing PaintAll paint shall be brought into the shop or onto the site in paint original containers. All paints, thinners, solvents, and any other liquids likely to contaminate land or water shall be stored and mixed within bunded areas.

All paints shall be thoroughly mixed so that all pigment is in suspension before use. If required by the manufacturer, zinc-rich paint shall be agitated during application to keep the paint homogeneous.

Curing agents or hardeners that are separately packaged shall be added and mixed with the base paint in accordance with the manufacturer’s written recommendations. Unused portions of mixed convertible coatings shall be discarded at the end of the manufacturer’s recommended pot life and shall not be added into freshly mixed paint.

TintingWhere successive coats of the same colour have been specified, alternate coats shall be tinted off-shade sufficiently to produce enough contrast to indicate complete coverage of the surface.

Conditions for PaintingUnless otherwise permitted by the manufacturer, ambient conditions shall be maintained during application and curing of paint as follows:

The substrate temperature is greater than 3°C above dew point and less than 45°C, The ambient air temperature is above 5°C, and, The relative humidity is less than 85%.

The Contractor is responsible for maintaining suitable controls to meet ambient weather requirements.

Difficulty in achieving these conditions should be foreseen by the Applicator and communicated to the CFP for review.

Application of PaintThe preferred method of paint application is by spray application, however, the Owner may permit brush or roller application. Requirements for thinning shall be in accordance with the manufacturer’s written instructions.

Painters shall be provided with wet film gauges to ensure that the specified film thicknesses are achieved.

PrimingAbrasive blast or mechanically cleaned areas shall be primed with a coat of paint within four hours. Re-blasting to freshen the surface will be required if the surface is left overnight.

Stripe Coating of EdgesStripe coating shall be performed by applying a separate layer of paint by brush, which is required for all welds, surface irregularities, edges, or corners. This coat shall be a full coat in contrasting colour. Achieving opacity in these areas is indication of suitable paint thickness. The most suitable stage for stripe coating is usually between application of the primer and intermediate coat.

Absence of stripe coating promotes early onset of corrosion propagating from these locations. Further information on stripe coating can be requested from the CFP.

ApplicationEach coat shall be applied uniformly and completely over the entire surface. All runs and sags shall be brushed out immediately or the paint shall be removed and the surface re-applied.

Repair of Coating DefectsEach layer of paint shall be inspected by the Applicator and all defects or damage to previous coats shall be repaired prior to applying additional coats.

Insufficient Thickness - Areas with an inadequate coating thickness shall be thoroughly cleaned and where necessary, additional coats applied until the specified thickness for each layer or area is achieved. Excessive Thickness - Areas with excessive thickness shall, unless otherwise agreed in writing with the Owner, have the overbuilt material removed, the substrate be re-prepared, and the correct thickness reapplied. Spot repairs - After cleaning, the coating around the damaged area shall be feathered and the full system reinstated.

Each coating may take multiple applications to meet the requirement.

The Owner shall be notified for inspection when the Applicator believes that the requirement has been met for each full layer of primer, intermediate, and finish coat.

Quality

MaterialsDuring the course of the work, the Owner may take samples of paint from site for independent testing. If the results of the test show that the paint concerned does not comply with the relevant specification, the Applicator (at own expense) shall remove the non- complying paint and repaint the area with an approved paint in accordance with this Specification.

The materials used shall be within their specified shelf life and any deteriorated or contaminated materials shall not be used, and as soon as practicable, shall be removed from the site. Materials shall be transported and stored under conditions recommended by the manufacturer.

All materials and thinners used shall be as-supplied in unopened identifiable containers with the label intact. The following information shall be available for each product used (including thinners):

The manufacturer’s Product Data Sheet (PDS) with instructions for use including (where relevant) the mixing ratio of components, induction time, pot life, and recommendations regarding storage, mixing, and application. The manufacturer’s Material Safety Data Sheets (MSDS).

DocumentationThe Applicator shall provide to the satisfaction of the Owner, an Inspection and Test Plan (ITP) and sample report forms. Approved templates are available at www.DocoPro.com

This plan will detail the procedures that will be undertaken by the Applicator to verify compliance with this Specification. The plan shall provide space for inspection by the Owner, Contractor, and Applicator.

Completed documentation shall be submitted to the CFP who will review and submit a recommendation to the Owner.

The Contractor shall always allow the Owner access to the work in progress and shall provide every facility for inspection at all stages of the work. Any work rejected by the Owner as not conforming to this Specification shall be made good at the Contractor’s expense.

The Applicator will monitor their own work and perform tests as are necessary to ensure that materials, equipment, and procedures comply with the Specification.

The Owner may engage an independent third-party inspector to witness the following inspection stages:

1. The weather measurements shall be taken by the Applicator immediately prior to, or during painting at a minimum of three measurements at hourly intervals to ensure compliance with the appropriate specifications. The measurement values shall be recorded with time of measurement on the Daily Inspection Report.

2. Surface preparation shall be inspected immediately prior to application of each area of primer coating application.

DocoPro

Applicator Compliance

Daily Inspection

Forms

Inspection and Test Plan (ITP)

3. Surface profile shall be tested in accordance with AS 3894.5. 4. The surface shall be free of dust or other contamination and tested in accordance with AS3894.6

returning a dust rating of 2 or less.5. Unless otherwise specified by the coating manufacturer, chloride contamination as determined by

AS 3894.6, shall be less than 70 mg/m2 for exterior above-ground steelwork.6. After priming, no further coats shall be applied without the Owner’s approval. The Owner may

require an independent inspection to be performed prior to application of cover coats.7. The method for determining dry film thickness shall be using AS 3894.3. The dry film thickness

(DFT) readings shall comply to the following criteria: Frequency of readings shall meet the requirement of AS 3984.3, Average of each batch shall meet the specified nominated DFT range, however, Individual readings for each coating, shall be:

o Not less than 80% of the specified average DFT range, and, o Not be thicker than 120% of the specified average DFT range for each coat.

Table 1 of this Specification provides the values required for each coat within the coating system.8. When required by the Owner, satisfactory adhesion shall be determined by the ‘X-Cut Tape Test’

using Method A of ASTM Standard D 3359, where an average rating of 4A or better is obtained and no single result is permitted to be worse than 3A.

9. Each coating and the completed coating system shall be substantially free from runs, sags, wrinkling, fat edges, dust, inclusions, irregular coated patches, brush marks, blistering and pinholes, and shall be free from breaks in the coating.Areas which contain a significant number of these defects shall be aggregated into a single larger repair zone. Any repaired area shall be re-inspected.

ReportingThe Applicator shall complete a daily inspection report of an approved format (www.DocoPro.com) for each work area and supply copies to the Owner at the end of each week. The report shall also record paint batch numbers and quantities used with detail regarding the type of surface preparation and paint system used.

WarrantyThe Contractor shall provide warranty for all coatings applied under this Specification including taking responsibility for any existing coatings that have been over-coated. The warranty term shall meet the requirements described in the project contract documentation.

The use of this Specification, coatings specified, or inspection or acceptance by the Owner shall not alleviate the Contractor from this warranty.

The warranty shall cover supply of all site establishments, equipment, labour, and materials to rectify any coating defects except for mechanical abrasion or chemical damage caused after completion of works.

DisclaimerThis document is written as a generic description offered free for the user. The information in this report is intended for information only. Its use or distribution implies the User has reviewed and approved the information herein. The information is supplied under license and RemedyAP makes no warranties about the work, and disclaims liability for all uses of the work, to the fullest extent permitted by applicable law. Use or citation of this document does not constitute an endorsement by RemedyAP of suitability to a specific structure or application. This document is not to be used as a project-specific specification. RemedyAP has dedicated this work (except for logos and artwork), to the public domain. This work may be distributed and utilized, even for commercial purposes, without prior permission. Any portions, extractions, reference, or modification to this document shall be appropriately cited

or attributed to Remedy Asset Protection (RemedyAP). Additional questions or inquiries can be directed to www.RemedyAP.com.au. Official citation shall be “Remedy Asset Protection, Specification RAP-NCC-0620, www.RemedyAP.com.au”, for any information reproduced in commercial or research material.

More Information

RemedyAP Our Vision, Our People, Our CultureThe Remedy Asset Protection (Remedy AP) mission is to provide detailed assessment and inspection services in accordance with the Asset Owner’s Specification and Industry Standards. Our inspection staff has practical problem-solving skills and good interpersonal abilities. The team has experience evaluating many different types of structures across various industries to bring those learnings to the inspection, treatment, and maintenance of your facilities for roles including:

Coatings Focal Point Independent Third-party Inspection

For more information on how we can add value to your team, view our Capability Statements online at www.RemedyAP.com.au

Our service is designed to assist your existing teams without costly duplication of services. We understand that corrosion is a small part of the development plan and therefore our service is focused on delivering value without excessive cost. Our engagement can be initiated by anyone in the development chain.

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Corrosion Control

Assess environmental

corrosivity zoneReview design

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Review coupling of

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Design of protective coatings systems

Re-assessment during framing

stages

Inspection at intermediate

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Final inspection

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