4. painting (second edition)

GOOD INDUSTRY PRACTICES

Copyright @ 2004 Building and Construction Authority, Singapore. All rights reserved. This document or any part thereof may not be

reproduced for any reason whatsoever in any form or means whatsoever and howsoever without the prior written consent and approval of

the Building and Construction Authority.

Whilst every effort has been made to ensure the accuracy of the information contained in this publication, the Building and Construction

Authority, its employees or agents shall not be responsible for any mistake or inaccuracy that may be contained herein and all such liability

and responsibility are expressly disclaimed by these said parties.

The publication includes advertisements of suppliers who have, in one way or another, contributed in the development of this publication.

The Building and Construction Authority does not endorse the products included in the advertisements. It is the responsibility of the users

to select appropriate products and ensure the selected products meet their specific requirements.

ISBN: 981-05-1531-6

Foreword

The Building and Construction Authority (BCA) has been promoting the use of Construction

Quality Assessment System or CONQUAS 21 as the de facto national yardstick for measuring

the workmanship quality of building projects. To meet the rising expectation of the

homeowners, the Quality Mark (QM) Scheme was launched in July 2002 to promote a

higher consistency in workmanship standards for residential developments.

This “Good Industry Practices – Painting” is part of the CONQUAS 21 Enhancement Series

on Good Industry Practices. The purpose of the guide is to share with the industry the

good painting practices adopted by practitioners and to raise awareness of the different

paint systems, the selection criteria and application processes. It provides simple and

practical suggestions on how good quality painting can be achieved on site. Common

defects associated with paints, their causes and preventive measures are also highlighted

in this guide.

In this second edition, the guide has been revised to include more good practices,

photographs and graphical presentations for easier reference and better illustration.

It should, however, be pointed out that this guide is not meant to dictate how painting

work must be carried out. It only serves to illustrate some of the good practices that

designers and applicators have adopted in selecting and applying paints. We gratefully

acknowledge the contributions of these practitioners and trust that the industry will find

this publication useful in its pursuit of quality excellence.

Lam Siew Wah

Deputy Chief Executive Officer

Industry Development

Building and Construction Authority

Acknowledgement

“Good Industry Practices – Painting” was first published in 2001. A Technical Committee

for Good Industry Practices for Painting was then formed to review and endorse on the

good practices identified.

We wish to again thank the members of the Technical Committee for their valuable

contributions.

Technical Committee for Good Industry Practices – Painting

Chairman : Mr Allen Ang Aik Leng BCA

Secretary : Ms Jessica Lim Sok Wei BCA

Members : Mr Yee Kee Kong REDAS

Mr Chan Kok Way SIA

Mr Simon Lee SCAL

Ms Lynn M Lee Nippon Paint (S) Co Pte Ltd

Ms Koh Sock Sang ICI Paints (S) Pte Ltd

Mr Matthias Chia I.R.E Corporation Pte Ltd

Ms Doris Tan SKK (S) Pte Ltd

Dr Lim Chooi Seng PSB

A/Prof. Michael Chew Yit Lin NUS

For this edition, we would like to thank the following organisations and individuals for

their supports and contributions in the review of this guide.

Real Estate Developers’ Association of Singapore (REDAS)

Singapore Institute of Architects (SIA)

The Singapore Contractors Association Ltd (SCAL)

Housing & Development Board (HDB)

Woh Hup (Pte) Ltd

Ando Corporation (Singapore Branch)

Dragages Singapore Pte Ltd

Shimizu Corporation (Singapore Office)

Look Architects

Nippon Paint (S) Co Pte Ltd

ICI Paints (S) Pte Ltd

SKK (S) Pte Ltd

STO SEA Pte Ltd

Cristin Farbwerkzeuge (Far East) Pte Ltd

Mr Lee Ho Mein

Mr Larry H.Brual

Mr Yan Naing Soe

Mr Khoo Boo Seong

Mr Alan Ng

Mr Look Boon Gee

Ms Lynn M Lee

Mr Vincent Chia

Ms Koh Sock Sang

Ms Doris Tan

Ms Audra Lee

Mr Lawrence T P Goh

Tan Tian Chong

Director

Technology Development Division

1. Introduction 11.1 Functions of Paint 11.2 Paint Systems and Components 21.3 Classification of Paint 31.4 Properties of Paint 3

2. Material Selection 42.1 Selection of Paint System 4

3. Delivery and Storage 163.1 Delivery 163.2 Storage of Paints 163.3 Storage and Maintenance of Application Tools 16

4. Preparatory Work 174.1 Planning 174.2 Surface Preparation 174.3 Paint Preparation 214.4 Protection Works Before Paint Application 224.5 Safety 24

5. Application 255.1 Guidelines to Good Paint Application 255.2 Application Tools 265.3 Application Methods 275.4 Protection Works After Application 295.5 Inspection of Completed Works 29

6. Common Defects 30

Appendix 39APPENDIX A : Examples of Paints Classified by Resin & 39

some of their General PropertiesAPPENDIX B : Categories of Environment According to 40

their Corrosive NatureAPPENDIX C : Laboratory Tests on Paint System 42APPENDIX D : Sample of Inspection and Test Plan 43APPENDIX E : Sample Checklist for In-process Inspection on 45

Painting WorksAPPENDIX F : Sample Checklist for Final Inspection on 48

Painting Works

References 49

Contents

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1. Introduction

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Functions of Paint

1.1 FUNCTIONS OF PAINT

Paint is a fluid that dries to form a continuous solid film when spread over a surface or substrate. Depending

on its type and properties, paint can perform one or more of the following functions:

Descriptions

• Paint can be used as a coating to decorate a surfaceor substrate. It has a wide variety of colour, texture,finishes and gross level.

a) Decorative

Decorative paint for aesthetic purpose

• Paint can be designed to protect the surface orsubstrate against ultra-violet rays, humidity,chemicals, corrosion, algae, abrasion etc.

b) Protective

Protective paint for fuel tanks

• Paint can also be formulated for specific uses suchas luminous paint that glow in the dark foremergency signage, anti-condensation paintto provide an insulating layer to minimisecondensation, fire retardant paint to enhance thefire resistance of combustible surfaces such assoftboard or hardboard.

• For application of special paints, refer tomanufacturer’s recommendations.

c) Special Purposes

Luminous paint for emergency signage

Table 1.1: Functions of Paint

FIREEXTINGUISHER

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1.2 PAINT SYSTEMS AND COMPONENTS

A paint system is basically composed of primer/sealer,undercoat and topcoat as shown in Figure 1.1.Depending on the design requirement, texture coatingmay be provided. Due to volume constraint, thisguidebook will focus on paints that are commonlyused in the local market. The functions of each systemcomponent are illustrated in Table 1.2 below.

Primer or Sealer

Texture (Optional)

Undercoat

Topcoat

Figure 1.1: Typical paint system

System Component

Primer

Function

– To improve adhesion– To protect metal against corrosion– To reduce porosity of receiving

substrate so as to prevent undueabsorption of resin from subsequentcoats of paints

Remarks

– Primer should be used to reducethe porosity of the surface and toprovide adequate moisture resistantcapability

– Etching Primer should be usedas pre-treatment on non-ferroussurfaces such as galvanised metals,aluminium to ensure good adhesion

Sealer – To resist alkali attack from cementbased materials

– To improve adhesion– To seal problematic surfaces, e.g.

resinous wood– To stabilise loose surface particles– To reduce porosity of receiving

substrate so as to prevent undueabsorption of resin from subsequentcoats of paints

– Sealers are applied to preventmigration of substances from thesubstrate into later coats and shouldbe used to reduce the porosity ofthe surface and to provide adequatemoisture resistant capability

Texture (Optional) – To give a distinct 3-dimensionalappearance.

– If applied, this is introduced as thesecond coat after application ofsealer/primer. Commonly appliedby spray or roller

– Textures are available in multiplecolours to simulate the look ofgranite, tiles, and wallpaper

– Mock-ups are important tounderstand the appearance of theproduct

Undercoat – To impart opacity and film build– To level out minor irregularities and

provide uniform texture– To improve inter-coating adhesion

– Choice of undercoat should becompatible with the primer/sealerand the finishing coats

Topcoat – To provide the required functionsof paint as discussed in Section 1.1

– This is the finishing coat of a paintsystem which gives the finalappearance in term of colour, glossor sheen to the substrate.

Table 1.2: Functions of the Various Components of a Paint System

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Classification by Type of Paints

Baking or Air-dry

Water-based or Solvent-based

Primer, Sealer, Undercoat or Finishing Coat

Epoxy, Alkyd, Acrylic, Polyurethane, etc

Architectural Coating, Heavy Duty Coating, Marine orIndustrial Coating

Curing Mechanism

Solvent for the Paint

Function of System Component

Resin component

Market Segment

Table 1.3: Classification of Paint

1.3 CLASSIFICATION OF PAINT

With technological advancements, the traditionalclassification of paints into either enamel or emulsionhas become misleading. Today, the industry has enamelpaints that can be diluted with water and emulsionpaints that have smooth, glossy finishes. Hence, itbecomes essential to identify paint by its resincomponents to minimise confusion.

Appendix A shows some examples of paints classifiedby their resin components and properties. In general,“enamel” refers to solvent-based Alkyd resin which isgenerally used for wood and metal surfaces.

Apart from classifying paints by their resin components,paints may also be classified in accordance with theircuring mechanism, solvent used, function and marketsegment as shown in Table 1.3.

1.4 PROPERTIES OF PAINT

The properties of paint determine the general quality of the coating and its workability, ease of application andresistance characteristics. Table 1.4 shows some basic properties of paints.

Properties Examples

Gloss/ Matt/ Semi-gloss

By Brush, Roller or Sprayer

Fast dry/ Slow dry

Adhesion to substrates/ Existing coating/ Intercoating

Hardness/ Flexibility

Ultra-violet/ Chemical/ Abrasion/ Fungus/ Algae

Gloss retention/ Colour / Ultra-violet

Settling tendency/ Viscosity stability

Appearance

Application Method

Drying Time

Adhesion

Mechanical Characteristics

Resistance

Outdoor Durability

Storage Stability

Table 1.4: Essential Properties of Paint

To rectify the root cause(s)

• Install waterproofing, provide proper drainage of condensed water from air-conditioners, reducethe density of foliage to reduce the occurrence of algae, etc.

• Refer to Section 6 for the recommended remedy

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Figure 2.1: Selection of Paint System

FOR COATED SURFACE

2. Material Selection

2.1 SELECTION OF PAINT SYSTEM

Different types and grades of paint systems have varying application and performance properties. Figure 2.1summarises the key considerations in determining the existing condition of coated surface as well as in selectingthe appropriate paint system.

To determine the root cause(s) of defects

• Sources of moisture, use of incorrect paint system, presence of alkaline, too porous substrate ,improper design of building and its facade etc.

To ascertain the presence of defects and problems

• Presence of seepage, peeling, discoloration, algae growth, etc.

• Refer to Section 6 for the types of defects.

FOR UNCOATED SURFACEFOR UNCOATED SURFACE

Basic Selection Criteria

• The common types of substrates are concrete/ cement based, timber and metalsurfaces. Different substrates require different types of primer/sealer. For example,external concrete wall surface will require the use of alkali resisting sealer whilstferrous metal surface will require corrosion inhibitive primer.

• Conditions refer to the substrate’s profile, porosity, and existing conditions etc.• Refer to Tables 2.1, 2.2 and 2.3 for details.

Type of Substrate andits Conditions

• Internal or external.• Identify types of adverse elements that the paint system will be subjected to.• Refer to Appendix B for detail classification.

Type of Environment

• Colour, texture and gloss level• Colour retention properties

Expected Appearance

• Durability period, weather resistance, algal resistance, UV resistance, alkali resistance,scrub resistances, chemical resistance, waterproofing characteristic, etc.

Expected Performance

• Balance and reconcile a realistic budget with the expectations.Budget

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Column Headings Explanatory Notes

Receiving surfaces are categorised according to the type of base substance of thesubstrate, i.e. concrete/cement plaster, timber or metal.

The surfaces have been further categorised into internal (sheltered) or externalenvironmental exposures.

Surface

In general, the various paint components used (that is the primer, sealer, intermediate coat and topcoat) shouldbe compatible. Tables 2.1 to 2.3 provide useful information on the various common paint systems available fordifferent surfaces and purposes. The following explanatory notes are for the use of Table 2.1 to 2.3.

Description is based on the required gloss level or texture.Finishes

A 4-point grading scale is used to highlight strengths and weaknesses of the keyproperties of the system.

Comparison of Properties

Description is based on the resin of topcoat.Paint Type

Description is based on the types of sealer/primer, undercoat and topcoat to be used.Numbers of coat to be applied are also indicated.

Typical Paint System

Brief description on the general applications.Remarks

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INTERNAL

Cement plasteredwalls and concreterelated surfaces,brickwork, plasterboards, gypsumboards, ceilingpanels

Table 2.1: Reference Chart for Selecting Paint Systems for CONCRETE/PLASTER SURFACE

Surface FinishesRequired

S/No Comparison of Properties Paint Type Typical PaintSystem

RemarksNo. ofCoats

Easein

Painting

Durability Anti-Algaeand

Fungus

AlkalineResistance

ChemicalResistance

MattM1 A ACRYLICCOPOLYMEREMULSION

C C C C Alkali resistingsealer

Acrylic emulsionSS150 (Type 2)

1

2

Quality matt emulsion.Lasting for most internal walls.

SheenM2 A VEOVA(MODIFIEDACRYLIC)EMULSION

B B C C Alkali resistingsealer

"Vinyl Silk"emulsion

1

2

Luxurious sheen emulsion thatgives a smooth and silkyappearance. Premium gradefor interior decor commonlysold as Vinyl Silk emulsion.

Low SheenM3 A ACRYLICEMULSION

A B B B Alkali resistingsealer

Acrylic emulsion

1

2

Premium grade with superbwashable surface properties

Low Gloss/

Gloss

M4 C EPOXYA A A A Epoxy sealer

Epoxy topcoat

1

2

Excellent chemical resistanceand very good hardness &abrasion resistance. Resistdefect by moisture.

Used in food, chemical orheavy duty environment.

EXTERNAL

MattM5 A ACRYLICEMULSION

C C B C Alkali resistingsealer

Acrylic emulsionSS150 (Type 1)

1

2

Good weathering and alkaliresistance.

As above and allfloor excludinggypsum types

Cement plasteredwalls and concreterelated surfaces,brickwork, mineralplasters

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EXTERNAL (cont’d)





RemarksNo. ofCoats

Easein

Painting


Fungus

AlkalineResistance

ChemicalResistance

Semi-GlossM6 B SOLVENT-BASEDACRYLIC

B B B B Alkali resistingsolvent-based sealer

Acrylic solvent-basedtopcoat

1

2

Excellent thermoplasticcoatings for fungus/algaeprone surfaces.

Excellent adhesion and gooddurability to weather.

Low SheenM7 A HIGHPERFOR-MANCEACRYLICEMULSION

B A A B Alkali resistingsealer

High performanceacrylic emulsionSS 345

1

2

High quality Acrylic emulsionwith anti algae/fungiproperties

GlossM8 C 2-PACKPOLYURE-THANE

A A A A Epoxy primer

Polyurethanetopcoat

1

2

Excellent weather, chemicaland abrasion resistance two-components paint system

SheenM9 A TEXTURECOATINGWATER-BASEDACRYLICTOPCOAT

B B A B Alkali resistingsealer

Texture base coat

High performanceacrylic emulsionSS345

1

1

2

Textured acrylic-based,decorative finish withalgistatic, fungistatic & anti-carbonation properties

Gloss/Semi-Gloss

M10 B TEXTURECOATINGSOLVENT-BASEDACRYLICTOPCOAT

B B A B Alkali resistingsolvent-based sealer

Texture base coat

Acrylic solvent-basedfinishing coat

1

1

2

Textured acrylic solvent-basedcoating with excellentadhesion

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EXTERNAL (cont’d)





RemarksNo. ofCoats

Easein

Painting


Fungus

AlkalineResistance

ChemicalResistance

GlossM11 B TEXTURECOATINGPOLYURE-THANETOPCOAT

A A A A Epoxy primer

Acrylic emulsiontexture base coat

Polyurethanetopcoat

1

1

2

Acrylic & 2-pack polyurethanecombination textured system.Excellent weather, chemicaland abrasion resistance

MattM12 A WATER-BASEDSILICONEPAINT

B B A B Water-based siliconeprimer

Water-based siliconepaint

1

2

Excellent alkaline resistancewith high water repellingproperties

NaturalM13 A PENETRAT-ING CLEARWATERREPELLENT

C C B C Solvent-basedpenetrating clearrepellent (coat tosaturation)

1-2 Protection from external stainsand treatment to moistureabsorption problem. Waterrepelling, fungus and weatherresistance.

NaturalM14 A ACRYLICSOLVENTBASED TILECOATING

B B B C Acrylicsolvent-based

2 Acrylic solvent- based coatingsfor fungus/algae proneconcrete and roof tiles.

Fair-face brick wall

Roof tiles(non-glazed)

Grading for Comparison of Properties LEGEND: A Excellent B Very Good C Good D Average

Notes:

1 All external systems are suitable for internal use.2 Resin level differs for paint types specified here. For resin and toxicity levels in paint, refer to manufacturers.3 All systems specified are for general painting purpose. Variation is subjected to site conditions or circumstances.4 For elastomeric coatings, please refer to SS 500:2002 - Elastomeric wall coatings for more information.5 For surfaces not covered here, refer to manufacturers.

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INTERNAL

All kinds of timberproducts or relatedmaterial

Table 2.2: Reference Chart for Selecting Paint Systems for TIMBER SURFACES



RemarksNo. ofCoats

Easein

Painting

Durability Hardness YellowingResistance

StainResistance

GlossT1 B ALKYDRESINENAMEL

D D D C Aluminium woodprimerSS 38

Alkyd enamelundercoatSS 34

Alkyd enamel glosstop coatSS 7

1

1

2

High gloss enamel for paintingof general doors & windows

GlossT2 D 2-PACKPOLYURE-THANE

A B A A Epoxy primer

Polyurethanetopcoat

1

2

Glossy, hard and solventresistant and non-yellowingtwo-components paint system.

SheenT3 A VEOVAMODIFIED(MODIFIEDACRYLIC)EMULSION

D D C C Aluminium woodprimerSS 38


"Vinyl Silk"emulsion

1

1

2

Decorative emulsion forpanels & ceiling trims.Commonly sold as Vinyl SilkEmulsion

Gloss &Satin

T4 D ACRYLICMODIFIEDALKYDNITRO-CELLULOSE(NC)LACQUER

D B D A NC acrylic lacquer 3 Aerosol spray for easyapplication on furniture

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INTERNAL (cont’d)





RemarksNo. ofCoats

Easein

Painting


StainResistance

NaturalT5 B ALKYDMODIFIEDPOLYURE-THANE1-PACK

C C C B 1-pack polyurethaneclear

3 Very durable varnish forfurniture, wood panels anddoors.

NaturalT6 C 2-PACKPOLYURE-THANE

B A B A 2-pack polyurethaneclear

3 Hard coating for furniture andwood panels

NaturalT7 C 2-PACKAMINO-ALKYDRESIN ACIDCURE

B A C A Amino-alkyd coatingclear

3 Very tough coating for parquetfloors, railing or furniture

NaturalT8 C 2-PACKEPOXY

B A C A Epoxy clear 3 Chemical-resistant coating forcorrosive environment, e.g.Laboratory benches.

EXTERNAL

GlossT9 B ALKYDRESINENAMEL

D D D C Aluminium woodprimerSS38


Alkyd enamel glosstop coatSS 7

1

1

2

High gloss enamel for paintingof general doors & windows.


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EXTERNAL (cont’d)





RemarksNo. ofCoats

Easein

Painting


StainResistance

GlossT10 D 2-PACKPOLYURE-THANE

A B A A Epoxy primer

Polyurethanefinishing coat

1

2

Chemical-resistant coating forcorrosive environment, e.g.Laboratory benches.

Low SheenT11 A ACRYLICEMULSION

D C B B Aluminiumwood primerSS38

Alkyd enamelundercoatSS34

Acrylic emulsion

1

1

2

Exterior grade emulsionsunder special requirement

NaturalT12 D 2-PACKPOLYURE-THANE

A B A A Polyurethaneclear

3 Very durable coat for externaltimber structures.


Notes:

1 All external systems are suitable for internal use.2 Resin level differs for paint types specified here. For resin and toxicity levels in paint, refer to manufacturers.3 All systems specified are for general painting purpose. Variation is subjected to site conditions or circumstances.4 For surfaces not covered here, refer to manufacturers.

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INTERNAL

(Ferrous type)Iron & steel relatedsurfaces

Table 2.3: Reference Chart for Selecting Paint Systems for METAL SURFACES



RemarksNo. ofCoats

Easein

Painting

Durability Hardness Corrosioncontrol

GlossF1 A ALKYDRESINENAMEL

C D C Alkyd-based anti-corrosion primer*


Alkyd enamel glosstopcoatSS7

1

1

2

*Refer to SS494 for Lead andchromate-free primer

Easy to use finishing coat overprimed metal surfaces undernon-corrosive environment.

Low Gloss/Gloss

F2 C EPOXYA A A Epoxy/Zincphosphate blastprimer

Epoxy topcoat

1

2

Epoxy system for corrosivechemical environment onblasted metal.

Low Gloss/Gloss

F3 C EPOXYA A A 2-pack high solidepoxy primer

Epoxy topcoat

1

2

High-build epoxy systemfor corrosive chemicalenvironment and NO GRITBLAST situation.

Low Gloss/Gloss

F4 C EPOXYA A A Epoxy coating 3 Epoxy system. ‘Non Toxic’suitable for potable tanks.Relevant certification shouldbe obtained before use


INTERNAL (cont’d)

(Non ferroustype)Galvanised metal,stainless steel,copper , tin& other relatedsurfaces




RemarksNo. ofCoats

Easein

Painting



C D C Etching primer

Alkyd-based anti-corrosion primer*



1

1

1

2


Easy to use finishing systemover properly primed surfaces.Under non-corrosiveenvironment, e.g. domestichome & commercial office.

Low Gloss/Gloss

F6 C EPOXYA A A Epoxy primer

Epoxy topcoat

1

2

Heavy-duty epoxy system forcorrosive environment such aschemical industry.

EXTERNAL


D D C Alkyd-based anti-corrosion primer*



1

1

2


Easy to use system fornon-corrosive environment,e.g. residential and commercialareas.


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EXTERNAL (cont’d)





RemarksNo. ofCoats

Easein

Painting


GlossF8 B ALKYD-BASEDMICACEOUSIRON OXIDE

C B B Alkyd-based anti-corrosion primer*

Alkyd-basedmicaceous ironoxide


1

2

2


Modified alkyd & micaceousiron oxide offering protectionin mildly corrosive & highlyhumid condition, e.g. towers,bridges, heavy structural steelworks.

GlossF9 C/B EPOXY/POLYURE-THANE

A B/A B/A Epoxy/ zincphosphate blastprimer

2-pack polyurethanefinishing coat

1

2

High performance Epoxy/Polyurethane system for highlycorrosive environment onblasted metal e.g. exposed tosea salt or highly corrosivechemicals.

GlossF10 C/B EPOXY/POLYURE-THANE

A B/A B/A 2-pack high solidepoxy primer

Epoxy built-coat

2-pack polyurethanefinishing coat

1

1

2

Epoxy/ Polyurethane systemfor highly corrosiveenvironment and NO GRITBLAST situation.

SheenF11 C EPOXY TARHIGH BUILD

C C B Ethyl silicate zincrich primer

Coal tar epoxytopcoat

1

3

Heavy duty Coal Tar systemfor long-term or periodicimmersion in sea water.


EXTERNAL (cont’d)

(Non-ferroustype)Galvanised metal,stainless steel,copper, tin &other related alloysurfaces




RemarksNo. ofCoats

Easein

Painting



D D C Etching primer


Alkyd enamelundercoat

Alkyd enamel glosstopcoat

1

1

1

2

*Refer to SS494 for Lead andchromate-free primerAlkyd resin enamel for non-corrosive environment e.g.residential, office & lightindustries.

GlossF13 A ALKYDMEDIUM-OIL TYPE

C C B Etching primer


Medium-oil alkydtopcoat gloss

1

1

2


Use in mild corrosiveatmosphere e.g. industrialchimney, mild chemicalprocessing plant

GlossF14 C EPOXY/POLYURE-THANE

A A A Etching primer

Epoxy primer

2-pack polyurethanegloss finishing coat

1

1

2

Heavy-duty Epoxy/Polyurethane system. Excellentin corrosive chemicalsconditions e.g. chemicalindustry, exposed to saltedseawater.


Notes:

1 All external systems are suitable for internal use.2 Resin level differs for paint types specified here. For resin and toxicity levels in paint, refer to manufacturers.3 All systems specified are for general painting purpose. Variation is subjected to site conditions or circumstances.4 For surfaces not covered here, refer to manufacturers.

3.1 DELIVERY

The properties of paints delivered for site applicationshould conform to the project specifications. Shelflife and colour of the paints should be verified againstthe documents furnished by the manufacturer. Newpaints should be delivered to site in sealed containers.

Random samples of the paints may be taken and sentto independent laboratories for testing. Refer toAppendix C.

3.2 STORAGE OF PAINTS

Paints have varying storage requirements andshould be stored according to manufacturer’srecommendations.

In general, paints should be stored in a cool, dry andwell-ventilated location away from sources of heat,ignition and direct sunlight. Smoking must be inhibitedand no unauthorized access to the storage place shouldbe allowed.

Paint containers which have been opened should beproperly covered and kept upright to prevent skinningand spillage. Containers should not be stored byhanging on hooks.

Paints with flash points between 21° and 32° Celsiusshould be stored in accordance with the HighlyFlammable Liquids and Liquefied Petroleum GasRegulation 1972.

3.3 STORAGE AND MAINTENANCE OF APPLICATION TOOLS

3.3.1 BrushesExcess paint can be removed with a piece ofthin blade before washing the brushes. Brushesshould be suspended in water or thinnersaccordingly, up to, but not above, the stock.

Brushes used for emulsion paints should bewashed immediately after use in clean runningwater. Varnish brushes should be suspendedovernight in the appropriate thinner. Chemical-reaction-paint brushes should be cleanedimmediately after use.

Brushes not required for some time should becleaned using suitable thinners or brushcleaner, washed in hot soapy water, rinsed andlaid aside to dry for future use.

New, unused brushes should preferably bestored in the original packages in which theyare delivered. Loose hair should be removedfrom the brushes before use.

3.3.2 RollersRollers and trays should be thoroughly cleanedafter use. Superfluous paint may be removedby rolling the tools on newspaper and thenwashing them in warm soapy water orappropriate detergent. After cleaning, spin-drythe rollers to recover their original shape andhang them up for drying before storage.

3.3.3 Spray GunsSpray guns and nozzles should be thoroughlywashed and soaked in water after use.

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3. Delivery And Storage

Figure 3.1 Paint containers should be stored upright

Figure 3.2 Washing of spray gun nozzle

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4. Preparatory Work

4.1 PLANNING

Quality control starts with good planning andmanagement. An Inspection and Test Plan, ITP (referto Appendix D) which lists down the project’sinspection and testing requirements should beprepared to detail the checks required to achievegood workmanship. The plan should cover theresponsibilities of each party, inspection methods,requirement references and frequency of inspections.Checklists for the in-process and final inspectionon painting works should also be prepared (as inAppendix E and F).

Prior to starting any painting work, it is important forthe parties involved to plan and agree on thecompatible paint system as per project specification,surface preparation method, sequence of work, dryingout time and method of access.

In general, the schedule of painting works should beplanned in relation to the work of other trades, so asto ensure that the surfaces to be painted are preparedon time and that the subsequent construction workswill not damage the paint work.

The applicator should confirm on the type and numberof coats, location of application, surface preparationmethod and application method are in accordance

with project specification. For verification of the paintcolour, uniformity and compatibility of the paintsystem, it is a good practice to have a mock-up unitfor the approval of the architect or owner before thecommencement of the actual works.

4.2 SURFACE PREPARATION

Good surface preparation is critical for the paint systemto function effectively. As the performance of the paintsystem depends largely on its adhesion with thesubstrate, and paint adheres best to surfaces that areclean and sound, it is essential to establish the requiredstandard and level of surface preparation works. Thereceiving surfaces should be dry, and free from foreignand unstable matters such as dust, dirt, rust, spatter,salt, grease, oil, loose paint film and so forth beforeproceeding with the painting work.

Works by other trades that might affect the paintingshould be satisfactorily completed. The applicatorshould inform the designer of any change in the natureor condition of the receiving surfaces, which maynecessitate modification of the specifications.

Refer to Table 4.1 to Table 4.4 for more details onsurface preparation for various types of surfaces.

Table 4.1 Preparation of Concrete/Cement Plaster Surfaces

Condition Tools/Methods Remarks

Uncoated Surface Coated Surface

Moisture – Checking with moisture meter – To ensure moisturecontent not exceeding 6%(or refer tomanufacturer’srecommendation)

– Allow drying afterplastering for minimumof 21 days (in compliancewith CP22)

– To ensure moisturecontent not exceeding 6%(or refer tomanufacturer’srecommendation)

– To check for source ofdampness

SurfaceContaminantssuch asconstruction soot,algae, loose paint-film (for coatedsurface only) etc

– High pressure water jetting – To remove foreign andunstable matters suchas construction soot,concrete/cementsplashes, cementsalts etc

– To remove loose particlesand existing paint withflaking, dirt or chalkingetc

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SurfaceContaminantssuch asconstruction soot,algae, loose paint-film (for coatedsurface only) etc

– Manual cleaning by chipping,scrapping or wire brushing

– To remove foreign and unstable matters such asconstruction soot, algae, concrete/cement splashes,cement salts, loose paint film etc

SurfaceImperfections(i) rough, open-

textured orcoarse-grainedsurfaces

– Sanding/grinding/skim coatingfollowed by rinsing with cleanwater and wiping dry

– Brushing or sweeping – To remove foreign and unstable matters such asconstruction soot, algae, concrete/cement splashes,cement salts, loose paint film etc

– Fungicidal wash – To kill fungal/algae spores and rootsSurface TreatmentMicrobiologicalgrowth, e.g. algaeor fungi growth

– To reduce roughness

– To improve adhesion to substrate/existing coating

– To remove foreign and unstable matters such asconstruction soot, algae, concrete/cement splashes,cement salts etc

(ii) hairline cracks,nail & screwholes, openjoints, cracks andsimilar localcavities, deep andshallowdepressions

– Patching – Use fillers that contain a resin/binder system e.g. acrylicbased putty or cement with additives

– Water sensitive types e.g. gypsum-based fillers arenot recommended as they may dissolve in water

– Prime surface before patching if oil-based fillers are used

– Patch in two stages if cavities are deep

– If applied immediately beneath finishing coats, shrinkageand variations in gloss, sheen or colour may occur

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Table 4.2 Preparation of Timber Surfaces



Moisture – Checking with moisture meter – To ensure moisture content not exceeding 15% (or referto manufacturer’s recommendation)

SurfaceContaminantssuch as dirt, grime,loose paint-filmetc

– Sanding manually ormechanically with sandpaperfollowed by wiping with dampcloth


– To remove foreign and unstable matters such as dirt, grime,loose paint-film etc

– To provide a smoother and better finish

– Stripping by paint removeraccompanied by scraping

NA – To strip off defective paintworks

– Chlorinated/alkalinepaint removernot recommended

SurfaceImperfections(i) nail & screw

holes, cracksand similarlocal cavities,deep andshallowdepressions

– Patching with wood putty orfiller

– Use wood filler for painting with transparent coatings

(ii) rough surface – Sanding/grinding/skim coatingfollowed by rinsing with cleanwater and wiping dry

– To provide a smoother and better finish


Surface Treatment – Priming – Prime all surfaces including abutting surfaces, e.g.doorframes.

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Table 4.3 Preparation of Ferrous Metal Surfaces



SurfaceContaminants(i) mill scale, rust

– On site: mechanical wirebrushing

– Wire brush till surface is free from rust (compliancewith ST 3 standards or equivalent)

– Off site: blasting – Compliance with SA 2.5standards (bare metalwith only traces of slightstains in spots or stripes)

– If condition allows,compliance with SA 2.5standards (bare metalwith only traces of slightstains in spots or stripes)

(ii) joints/weldedareas/spotrusts, oil,grease, dirt,loose paintfilm, abrasiveresidue, debrisetc

– Manual cleaning by chipping,scraping and/or wire brushing

– To remove foreign and unstable matters such as grease,oil, loose paint film, abrasive residue etc

– Manual or mechanical washingdown with solvent or detergentsolution

– To remove foreign and unstable matters such as grease,oil, loose paint film, abrasive residue etc

– Blasting – Compliance with SA 2.5standards (bare metalwith only traces of slightstains in spots or stripes)

– If condition allows,compliance with SA 2.5standards (bare metalwith only traces of slightstains in spots or stripes)

– Stripping by paint remover NA – To remove loose paintfilm

– Alkaline paint removermay be used

Surface Treatment – Washing with clean water andallow it to dry

– To improve adhesion/existing coating

– Priming exposed steel – To prevent corrosion

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Table 4.4 Preparation of Non-Ferrous Metal Surfaces(include aluminium, aluminium alloys, magnesium alloys, zinc and treated steel such as galvanised surfaces, anodised aluminium etc)



SurfaceContaminants(i) oil, grease

– Wiping with cloth dampenedwith solvent

– To remove grease and oil

– Mechanical washing down withsolvent or detergent solution

– To remove grease and oil

– Degreasing – To remove grease and oil

(ii) loose paint-film, dirt, rustetc

– High-pressure water jettingfollowed by sanding

– To remove foreign and unstable matters such as loosepaint film, abrasive residue etc

– Stripping by paint removers NA – Rinse thoroughly withclean water after strippingto avoid chemicalreaction with metal. Milddetergent should be usedto remove residue

– Sanding – To remove foreign andunstable matters such asloose paint film, abrasiveresidue etc

– White rust need not beremoved if found stable

Surface Treatment – Coating the exposed surface withan etching primer.

– To ensure good adhesion – To ensure good adhesion

– Spot prime exposedsurfaces immediatelyafter cleaning

4.3 PAINT PREPARATION

Proper paint preparation is important in deliveringquality work. Refer to Table 4.5 for details onpreparation of paint.

In mixing of paint, the following factors should beconsidered:

• mix ratio;• type of thinner used;• induction time;• pot life; and• ageing time

Mixing should be carried out in compliance with thespecifications and manufacturer’s recommendation.No unauthorized thinning or adulteration should becarried out and no addition of driers is permitted.Where additions are authorized, the correct proportionsshould be strictly observed.

There should be sufficient stirring until uniformity ofthe paint is achieved. The pigment in paints is heavierthan the vehicle and tends to settle at the bottom ofthe container. Failure to stir the paint properly is acommon cause of unsatisfactory results. It is, hence,essential that the paint is completely uniformthroughout the container.

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Table 4.5 Preparation of Paint

Condition

Confirmation ofSpecification

Methods/Tools

Visual checking

Remarks

– Inspect name of paint, colour,location of application and numbersof coats

Settling of solidconstituent in paints

Stirring:a) Manual

– Long, broad-bladed stirrer– Boxing (i.e. pouring from one

container to another several times)

b) Mechanical– use of mechanical equipment

– Stir continuously until no solidsettlement remains

– Refer SS CP22 on ‘Mixing &Thinning of Paints’

– Used for small quantities

– Used for large quantities

High viscosity paint Thinning – To assist workability

– Use type and proportions of thinnerin accordance to manufacturer’srecommendations

– Thinning to be carried out undersupervision

Mixing different brandsor types of paints

Not recommended Not recommended

Using 2-pack materials Mixing of two components – Use the correct proportion inaccordance to manufacturer’srecommendation

– Check the following:• Induction Time• Pot Life• Age-ing Time

– Use paint within the pot life

4.4 PROTECTION WORKS BEFORE PAINT APPLICATION

It is a good practice to plan the sequence of workssuch that the final coat will be painted only after thecompletion of other trades such as installation ofdoors and carpentry works. This will ensure that thefinal coat of paint will not be stained during theexecution of other trades.

All surfaces not intended to be painted must beprotected. Doors, furniture, light fittings and similaritems should be covered. Care should be taken whenprotecting surfaces that are sensitive to adhesive tapes.

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Figure 4.1 Examples of protection works before paint application

Air Conditioner – Fan Coil Unit Window

Building Materials Electrical Wirings

Floor, Sliding Door Frame and Railing Lift Button Panel and Cabinet

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4.5 SAFETY

Applicator should be equipped with safety attire/equipment, including proper working clothes, footwearand helmet. A safety belt should be used where paintingis being carried out at heights. Protective accessoriessuch as goggles or masks should be worn wherenecessary.

Proper access such as scaffolding and gondola shouldbe provided to facilitate external painting works.Applicator should also make sure that there is adequateventilation and illumination when carrying outpainting works, especially for internal areas.

Figure 4.2 Proper access and safety measures for surface preparation and external painting works

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5. Application

5.1 GUIDELINES TO GOOD PAINT APPLICATION

5.1.1 Differing ColoursWherever practicable, successive coats in paintsystems should differ in colour. This assistsapplication of continuous coats of uniformthickness (especially in conditions of poorlighting) and also facilitates inspection.For application, refer to manufacturer’srecommendations.

5.1.2 Intervals Between CoatsGenerally, each coat in the system should bedry throughout its thickness before the nextcoat is applied. Rate of drying should followthe recommendations of the manufacturers.Over exposure may lead to impaired adhesion.

For ‘wet-on-wet’ application (that is a secondcoat can be applied immediately after the firstcoat), refer to manufacturer’s recommendations.

5.1.3 Intercoat PreparationReceiving surface should be free fromcontaminants before application of each coat.

Light sanding with fine-grade, preferably partlyworn, sandpaper can be used to remove ‘nibs’and adherent dust particles. This helps toimprove adhesion and provide a smooth,leveled surface. Wet sanding is applicable ifextensive sanding is necessary. However, thecoating must have hardened before any sandingwork can be carried out. If the coatings scratchor tear, or the abrasive paper rapidly clogs, it isan indication that the surface is not sufficientlyhardened to permit abrasion.

5.1.4 Environmental ConditionsPrior to painting, the following environmentalconditions should be complied with:

5.1.5 Unfavourable Weather or UnsuitableConditionsPainting should not be carried out inunfavourable weather or unsuitable conditions.The application of paint to damp surfaces couldresult in flaking and blistering due to lack ofpaint penetration into the surface pores andpressure build-up of water vapour behind thecoating. It should be noted that surfacedampness is not always apparent, particularlyif the surface is flat and porous, such as a plasteror an undercoated surface.

Painting performed on surfaces directly exposedto the sun on a hot day may be subject topatchiness or sheariness. The heat causes thethinners to evaporate too quickly, making thepaint difficult to be applied and causesinterference with its flow.

5.1.6 Defective PaintApplicator should stop application if paintappears to be defective. Investigation shouldbe conducted to ascertain the cause of defects.Remedial works should be carried out beforepainting work can proceed.Figure 5.1 Sanding between coats of paints

Check Criteria

– Ambient temperature> 5°C or refer tomanufacturers’recommendation

– Surface temperature ofsubstrate < 60°C or referto manufacturers’recommendation

– Surface temperature ofsubstrate > 3°C +ambient temperature orrefer to manufacturers’recommendation

– Refer to manufacturers’recommendation

– No airborne dust and/orpollutant in environment

– No strong wind

Ambient Temperature

Substrate surfacetemperature

Relative humidity

Pollution level

Wind condition

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5.2 APPLICATION TOOLS

Applicator should ensure that operatives are skilled and experienced in the techniques of application, care andmaintenance of tools and equipment and, where relevant, the setting up and adjustment of equipment to obtainoptimum results.

Common Tools/Equipments

Brush

Description

• Flat paint brushes ranging from12mm - 100mm.

Application

For general paints and coatings onsmall and narrow areas where paintrollers are inaccessible.

Ideal for line cutting and touch-uppainting jobs.

Roller • Paint rollers are manufacturedusing various materials for theapplication of different paint typesand surfaces.

• The common sizes are 100mm,150mm, 175mm and 200mmwide.

• Different roller nap/ pile lengthare meant for different usage.

For all paints and coatings on smalland large areas.

Rollers can be used on all substrateswith smooth to rough surfaces.

Most rollers may be mounted on anextension pole to extend theoperative’s reach.

Roller Nap / Pile Length

Extra short pile

Usage

For smooth surface

Applicable for oil-based, polyurethane,epoxy paints and varnishes

Short pile For smooth surface

Applicable for emulsion and oil-basedpaints

Long pile For rough textured or uneven surface

Applicable for emulsion and masonrypaints

Sprayers (1) Airless Sprayer makes use of highpressure pump to eject paint.Paint output can be as much as10 litres in one minute.

Mainly use for large areas where spraypainting is permissible

For smooth and rough surfaces

Applicable for all paints and coatings

Airless Spray Gun

Paint Pump

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Common Tools/Equipments

Sprayers

Description

(2) Air Sprayer uses compressed airto force the paint from thecontainer to the spray head. Paintoutput can be as much as 0.5litre in one minute. It is mainlyused for furniture spraying andtexture coating.

(3) Air-Assisted Sprayer requires airsupply from a compressedpressure tank to operate. Paintoutput can be as much as 5 litresin one minute.

Application

Mainly use for large areas where spraypainting is permissible

For smooth and rough surfaces

Applicable for all paints and coatings

Texture coatings can be done withHopper/Mortar Gun

Air Compressor

Spray Gun

CompressedPressure Tank

5.3 APPLICATION METHODS

Method

Brush Application

Basic Technique

• Dampen the brushes prior topainting. Use water for latex oremulsion paints and paint thinnerfor oil or alkyd paints. Removeexcess water or thinner.

• Dip half the length of the bristlesinto the paint. Tap the brush gentlyagainst the side of the can to drainoff the excess paint.

• Use the bristle tips to paint acomplete stroke in one directionin continual length or breadth atabout one arm length.

Good Practices

• For new brushes, remove the loosebristles before use.

• Avoid immersing the whole brushhead into the paints or coatings.

• Avoid exerting too much pressurein working the bristles against thesurface during painting.

• Do not allow too much paint onits bristles during application tominimise paint drooling on thesurface.

• Verify with supervisor whethersurvey markings should be paintedover.

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Method

Roller Application

Basic Technique

• Roll from high to low using “W”format followed by “M” format tooverlap. This technique is widelyused to evenly disperse the painton the surface and to minimiseroller lines.

Good Practices

• For new roller refill, immerse it inpaint and roll it over paper/ surfacefor about a minute to season itbefore use. This will prevent refillfabric from adhering to the paintedsurfaces during application.

• Use the right roller withappropriate pile length for thepainting works for betteruniformity and evenness in thepaint coating.

• Do not roll on an ad-hoc basis, asthis will tend to create roller linesor marks on the surface.

Spray Application • Spray painting by pressing thetrigger to eject the paint onto thesurface; stroke by stroke verticallyor horizontally.

• For airless spray, maintain adistance between the nozzle of thegun and surface of about 1 m oras specified by manufacturers.

• Use clean and appropriate sprayingtip / gun nozzle for the spray-painting work. Generally, the sizeof the spraying tip will depend onthe paint consistency.

• Appropriate pump pressure levelshould be used for each spraying.

• Masks should be used duringspraying to prevent inhaling toxinand dust.

• Never point the spray gun atanybody when the equipment isin operation.

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Items To Check

Protection works after application

Appearance

Thickness (optional)

Adhesion

Curing Condition

Description

Check that all barricades and warning signs are put up.

Check colour, hue, texture (if applicable) and evenness of paint film byvisual assessment.

Check wet film thickness using a wet film gauge.

Check dry film thickness:

• Metals: The thickness can be measured with magnetic or electrical gauge.The latter is more accurate and can measure film thickness on bothferrous and non-ferrous surfaces.

• Masonry: The thickness can be measured by cutting a cross-section ofthe paint from the wall for examination by qualified technician.

Check adhesion of paint system after sufficient curing using adhesive tape.

Allow for adequate curing period of paint film (refer to manufacturer’sspecifications for curing period).

5.4 PROTECTION WORKS AFTER APPLICATION

Upon completion of the painting works, the finished works should be protected from staining and damages.Protection for finished works can be achieved by placing barricades around the areas with a “Wet Paint” sign torestrict access.

5.5 INSPECTION OF COMPLETED WORKS

The completed works should be inspected for the following:

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6. Common Defects

A paint defect is in many cases due to a number ofcauses. In some cases, several defects may occursimultaneously and hinder the determination of thecauses and redemption works.

To achieve good painting work, applicators and sitesupervisors should understand the causes andpreventive measures of common defects that occur atdifferent stages of works. They should also be familiarwith the remedial measures that can be taken to rectifyany unforeseen defect.

In general, paint defects can occur during:

• Paint storage;

• Application, drying and curing; and

• Service life.

Refer to Table 6.1 to 6.3 for details on the causes,preventive measures and remedial methods for thesecommon defects.

Defects

SettlingSettlement of pigment to the bottomand failure to re-disperse.

Causes

• Insufficient stirringduring storage

• Storage for longduration or underexcessively warmcondition

• Excessive dilution ordilution withunsuitable materials

Table 6.1 Common Defects During Paint Storage

Preventive Measures

• Store asrecommended bymanufacturer

• Avoid direct sunlightand long storage

• Dilute withappropriate thinnersas recommended bymanufacturer

Remedial Methods

• Stir paint to ahomogeneousconsistency

• Employ mechanicalstirring for heavysettling

• Move to appropriatestorage conditions asrecommended bymanufacturer

• Discard paint

SkinningFormation of a layer of skin on thecontainer.

• Use of non-airtightcontainer

• Poor formulationsuch as lack of anti-skinning agent

• Storage underexcessively warmcondition

• Use airtight container

• Avoid unnecessaryopening of can

• Store asrecommended bymanufacturer

• Remove the layer ofskin and stir paint tohomogeneousconsistency

• Inform manufacturerfor poor formulation

• Move to appropriatestorage conditions asrecommended bymanufacturer

GellingDecreasing viscosity caused bybacterial degradation of the proteinbinder or other thickening agents.This is often accompanied by anoffensive odour.

• Use of contaminatedtools andwater/solvents

• Mixing of differentbrands or types ofpaints

• Use clean tools andwater/solvents

• Avoid mixingdifferent brands ortypes of paints

• Discard paint

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Defects

BleedingLeaching out of the existing paintfilm.

Possible Causes

• Frequent brushing onthe same spot

• Use of incompatiblecoats or thinner

Table 6.2 Common Defects During Application, Drying and Curing

Preventive Measures

• Use properapplication method

• Apply withappropriate coat andthinner in accordancewith manufacturer’srecommendation

Remedial Methods

• Allow drying beforepainting over with anappropriate “buffer”coat (refer tomanufacturer’srecommendation)

Running/ Sagging/ CurtainingFlowing or dripping of paint fromupper vertical surface to the lowerpart forming a tear-like or wavyappearance.

• Painting ofexcessively thick filmlayer at one time

• Excessive dilution

• Application of glosspaint on existingpaints or surfacewithout sanding

• Increase frequency ofpainting thin film

• Lower dilution ratioeven whereoperability is poor

• Sand and cleanreceiving surfacebefore application

• Apply withappropriate coat inaccordance tomanufacturer’srecommendation

• Remove paint film,sand, clean andre-paint as in“Preventive Measure”

Wrinkling/ RivellingFormation of undulating wrinklingfilm.

• Application of thickOil-Alkyd, whichcauses shrinkage ofpaint film. This tendsto occur when dryingis expedited at hightemperatures

• Painting overinsufficiently driedpaint


• Apply withappropriate coat inaccordance withmanufacturer’srecommendation

• Avoid painting inthick film

• Avoid accumulationof paint around bolts,angles, etc.

• Observe overcoatingintervals inaccordance withmanufacturer’srecommendation


CrawlingSlipping or inability to form a film.

• Painting over surfacesthat are not prepared,e.g. sand, dirt anddust on the surface


• Apply withappropriate coat inaccordance withmanufacturer’srecommendation


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Defects

CratingFormation of small bowl-shapeddepressions.

Possible Causes

• Painting over surfacesthat are not prepared,e.g. sand, dirt anddust on the surface

• Use of contaminatedtools andwater/solvents

Preventive Measures


• Apply withappropriate coat asrecommended bymanufacturer

• Use clean tools andwater/solvents

Remedial Methods


LiftingAttacking by successive coating onexisting paint.

• Use of incompatiblecoats, which causeshrinkage of paintfilm or attacking ofthinner on undercoat

• Observe overcoatingintervals asrecommended bymanufacturer

• Allow undercoatingto dry beforeapplication ofsuccessive coating


• Apply withappropriate coat asrecommended bymanufacturer


Prolonged Drying TimeInability to dry after application.

• Incorrect mixing

• Use of defective paint

• Mix as recommendedby manufacturer

• Discard paint if it isdefective


Loss of GlossReduction of lustre on drying causedby severe absorption of undercoat.

• Application on roughor unclean surfaces

• Inadequate orexcessive dilution

• Use of unsuitablethinner

• Application ofexcessively thin film

• Result as blushingoccur

• Drying occurs in thepresence of excessivemoisture andpollutant

• Increase frequency ofpainting in thin film

• Paint adequatethickness of film

• Use appropriatethinner asrecommended bymanufacturer

• Avoid painting athigh humidity

• Prepare receivingsurface and applyappropriate sealer


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Defects

Efflorescencea) Migration of alkaline from

cement based materials andcrystallisation on the surfaceas salts.

Causes

• Painting overinsufficiently curedplaster/concrete

Table 6.3 Common Defects During Service Life

Preventive Measures

• Paint on receivingsurface with moisturecontent notexceeding 6%(or refer tomanufacturer’srecommendation)

Remedial Methods

• Removeefflorescence,unstable matters andloose paint film

• Repaint on receivingsurface with moisturecontent notexceeding 6%(or refer tomanufacturer’srecommendation)

• Seal off withcompatible alkaliresisting primerbefore painting

• In most persistentcases, epoxy-basedpaint has been usedwith good success butat a higher cost

• Painting oversubstrate’s hairlinecracks

• Paint on substratewith cracks notvisible at 1.5m awayfrom walls

• Patch cracks


• Water seepagethrough roof,toilets etc

• Install properwaterproofing systembefore painting.

• Arrest moisturesource

• Prepare and treat thesurface


• Rise of dampnessfrom ground

• Install properwaterproofing systembefore painting

• Treat dampness


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Defects

b) Migration of inherent wood gumand resins in timber.

Causes

• Painting overinsufficiently driedtimber

• Failure to use primer

Preventive Measures


• Apply appropriateprimer to seal thesurface beforepainting with theundercoat andtopcoat

• Observe overcoatingintervals inaccordance withmanufacturer’srecommendations

Remedial Methods


• Apply appropriateprimer to seal thesurface beforerepainting with theundercoat andtopcoat

c) Discolouration of paintworkon metals.

• Failure to removeunstable matterduring surfacepreparation

• Employ good surfacepreparation beforepainting

• Clean surfacethoroughly beforerepainting

Deterioration / Erosion of Pigment • Use of vibrantcolours paint withorganic particles thatare easily susceptibleto UV degradation

• Use of paint withwater sensitivepigments

• Use of paint with lowquality emulsions

• Select colours that aremore stable

• Use appropriatecoating system

• Remove powder andunstable matter

• Repaint withappropriate coatingsystem

• Select colours that aremore stable

Yellowing • Use of paint withcertain ingredients,e.g. yellowing epoxyand alkyd resins,which are easilyaffected by light, heator environmentalcontaminants

• Use non-yellowingpaints

• Prepare surface andrepaint with non-yellowing paints

Saponification • Use of alkyd-basedpaints on cementbased materials. Thealkalis from thecement attack the oilin the alkyd resin

• Avoid using alkyd-based paints oncement basedsurfaces

• Use appropriatecoating system

• Remove paint workand repaint withappropriate system

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Defects Causes

• Use of non-weathering resistantpaint

Preventive Measures

• Use weather resistantpaint for areasexposed to weatheror UV

Remedial Methods

• Prepare surface andrepaint withappropriate system

ChalkingNatural ageing of paint. The extentof chalking will depend on paintformulation and surface exposureto weather.

• Water seepagethrough roof,toilets etc

• Install properwaterproofing systembefore painting

• Arrest moisturesource

• Prepare and treat thesurface


Peeling & Flaking Painta) Moisture related

• Painting overinsufficiently curedplaster/ concrete


• Remove efflorescence,unstable matters andloose paint film


• Failure to useprimer/sealer

• Failure to use etchingprimer for non-ferrous metals

• Use of poor alkali-resistingprimer/undercoats orinsufficientpenetrative primer

• Prime/seal all baresurfaces withappropriate primeror sealer

• Remove all defectivepaint work andprepare the surface

• Repaint withappropriate system

b) Incorrect Paint System

• Failure to removeunstable matterduring surfacepreparation

• Use of water-solubleputty/ poor adheringplaster

• Employ adequatesurface preparation toremove all unstablematter

• Surface must beclean, dry and stablebefore receiving paint

• Remove all defectiveand loose paint film,and unstable mattersuch as plaster etc

• Prime/seal the surfacewith appropriateprimer/sealer tofurther stabilise thesurface

• Re-coat withappropriate coatingsystem

c) Poor Surface Preparation

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Defects Causes

• Painting on a warmsurface

• Moisture migrationthrough paintedsurface

Preventive Measures


Remedial Methods

• Remove defectivepaint and preparesurface accordingly toreceive paint


BlisteringThis is a moisture-relatedphenomenon. The amount ofmoisture and flexibility of the paintfilm determine the size of the blister.

• Use of detailsthat traps andaccumulates dirt.Streak marks areformed when dirtgets washed downalong the sides of thepainted vertical walls,especially onelastomericcoated wall.

• Avoid details andcoatings that trap andattract dirt

• Remove defectivepaint and preparesurface accordingly toreceive paint

• Apply with moredirt-resistant paintsystem

StainingIt should be noted that staining maybe attributed to improper design ofthe building and its façade.

• Yellowish-brownstains caused bymoisture

• It can be anindication ofwaterproofingproblem in otherparts of the building

• Ensure all potentialwater leakage andcondensation are incheck

• Arrest moisturesource.

• Prepare and treat thesurface.

• Repaint on receivingsurface with moisturecontent notexceeding 6%(or refer tomanufacturer’srecommendation).

• Repaint withappropriate system.

• Corrosion of metalelements that areattached to, adjacentto or embedded in,another substrate

• Installation of metalelements that are nottreated

• Protect and treat allmetal parts fromcorrosion

• Remove metal partsand treat the metalsurface

• Clean the walls andprepare the surface toreceive painting

• Repaint withappropriate system

Rust Stains

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Defects Causes

• Moisture source andretention

• Employing of detailsthat assist growth ofalgae/fungi:

(i) Profile of substrates;rough-textured finishes or rough concrete surfaces

Preventive Measures

• Avoid details withvery rough textures orrough-cast plasteredfinishes

• Use a more algaeresistant paint todelay the onset ofalgae growth

• Use capping andcopings

• Employ overhangingroofs to protect thewalls

Remedial Methods

• Remove dirt andalgae by high-pressure water jetting

• Treat infected areaswith fungicidal wash

• Re-paint with a morealgae resistant paint

Algae & Fungi Growth• Temperature, humidity

conditions and moisture contentof the surfaces/ substrates woulddetermine the likelihood of algaeand fungi formation.

• On buildings, algae are generallyfound outdoors such as externalwall surfaces, as their chlorophyllcharacteristic requires sufficientsunlight for growth. Whilst fungiare commonly found on internalwall surfaces of damp areas suchas bathrooms.

• It should be noted that algaegrowth may be attributed toimproper design of the buildingand its façade.

Overhanging roof details Overhanging roof

Capping details

MOISTURESPORES

OUTDOOR

ALGAE

SUNLIGHT

(ii) Condensation-pronewalls

• Increase thickness ofwall to provide moreinsulation so as tominimise thetemperature difference


• Incorporateinsulating material inthe concrete

• Apply a coating ofanti-condensationpaint

• Remove algae byhigh-pressure waterjetting

• Supplemented withmanual scrubbing ifnecessary

• Treat infected areaswith fungicidal wash

• Insulate with an anti-condensation coating


• Divert condensedwater from air-conoutlets with trays andpiping

(iii) Concrete gutters & water-prone areas

• Ensure properdrainage

• Avoid potential waterretention

• Use a more algaeresistant paint

• Ensure goodworkmanship


• Treat infected areaswith a fungicidalwash


Condensedwater promotedalgae growth andtrapped dirt.

Wet area belowthe potted plants

Scupper drains

INDOOR

MOISTURESPORES

FUNGI

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Defects Causes

(iv)Ledges

Preventive Measures





Remedial Methods




Ledges can causeback splashes byrainwater. If thisrainwater is slowto run down ordry, it can create amoist surface thatwill induce algaegrowth.

(v) Water drainage pipesand fittings







• Rectify the waterdrainage problem


Corrodeddown-pipes andprotruding air-conditioned unitswith no properdrainage pipes.

(vi)Precast Grille Vent • Avoid porous surfacesfor areas exposed toweather

• If necessary, seal orwaterproof poroussurfaces




• Seal and waterproofthe surface

• Re-paint with a morealgae resistant paintto delay the onset ofalgae growth

Such detail allowsretention of water.These surfaces arelikely to be moreporous too.

appendix A39

WATER-BASED

Examples of Paints classified by Resin & some of their General Properties

SOLVENT-BASED

Resin Classification Acrylic VA/AcrylicCopolymer

PVA Copolymer Epoxy (2-pack) Polyurethane Alkyd Acrylic Epoxy(2-pack)

Polyurethane Fluorocarbon

Principal Ingredient MethymethacrylatemodifiedAcrylic

Vinyl AcetateCopolymer

PolyvinylAcetateCopolymer

Epoxy resin +amine,polyamide resin

Polyurethaneresin

Oil-modifiedphthalic acidresin

MethylmethacrylatemodifiedAcrylic

Epoxy resin +amine,polyamide resin

Polyurethaneresin

PolyvinylideneFluoride

Main Usage GeneralCementitious-based Surface

InternalCementitious/Gypsum Surface

InternalCementitious/Gypsum Surface

InternalChemicalEnvironment

ChemicalEnvironment

General steelframes, woodensurfaces

GeneralCementitious-based Surface

InternalChemicalEnvironment

ChemicalEnvironment

Aluminiumcladding andextrusions

Du

rab

ilit

y o

f p

ain

tC

lass

ific

atio

n o

f re

ceiv

ing

ob

ject

Suit

abil

ity

to r

ecei

vin

go

bje

ct

Chalkresistance

Waterresistance

Acid proof

Alkali proof

Residential

Industrial area

Seaside

Water dip

Salt water dip

High humidity

Corrosionresistance

Ease in Painting

Iron

Wood

Concrete

Legend - Very Good - Good - Fair - Average - Poor - Not Applicable

Appendix A

appendix B

40

Characteristic

Categories of Environment according to their Corrosive Nature

Recommended Paint Type based on the Resin Family

INTERNAL

Description

Water-Based Solvent-Based

Highly-Corrosive – Chemical storage facilities.

– Factory exposed to constant acidic fumes or structuresimmersed in water.

– Chemical factory using acidic and other aggressivematerials in its process.

Epoxy (2-pack)Polyurethane (2-pack)

Epoxy (2-pack)FluorocarbonPolyurethane (2-pack)Silicone (2-pack)

Corrosive – Factory exposed to mild acid, alkaline, heat and highhumidity.

Epoxy (2-pack)Polyurethane (2-pack)

Epoxy (2-pack)FluorocarbonPolyurethane (2-pack)Silicone (2-pack)

Mildly-Corrosive – Light industries with mild corrosive environment. Epoxy (2-pack)Polyurethane (2-pack)AcrylicSilicone

Epoxy (2-pack)FluorocarbonPolyurethane (2-pack)Acrylic

Non-Corrosive – Residential andcommercialcomplexes withno moisturecondensation andchemicals exposure.

Epoxy (2-pack)Polyurethane (2-pack)SiliconeAcrylic

Epoxy (2-pack)FluorocarbonPolyurethane (2-pack)AcrylicAlkyd

Appendix B

appendix B41

Characteristic

Categories of Environment according to their Corrosive Nature

Recommended Paint Type based on the Resin Family

EXTERNAL

Description

Water-Based Solvent-Based

Highly-Corrosive – Structures immersed in sea.

– Structures exposed to constantsunlight or industries withpolluting fumes.

– Structures exposed to highhumidity e.g. oils refineries.

Polyurethane (2-pack) FluorocarbonPolyurethane (2-pack)Silicone (2-pack)

Corrosive – Structures near to sea.

– Structures exposed to Industrialpollutants with severalchimneys e.g. power stations,heavy industrial complexes.

Polyurethane (2-pack)Acrylic

FluorocarbonPolyurethane (2-pack)Silicone (2-pack)Acrylic

Mildly-Corrosive – Commercial areas withhigh-traffic density or industrialestates with fumes-emittingoutlets

Polyurethane (2-pack)AcrylicSilcone

FluorocarbonPolyurethane (2-pack)Acrylic

Non-Corrosive – Residential and Inlandsurroundings.

AcrylicSilicone

FluorocarbonPolyurethane (2-pack)Acrylic

Note: Examples of main corrosive components are SO2, CO2, NOx, Cl2 and industrial dust.Moisture will aid and accelerate chemical activity.

Appendix B

appendix C

42

Laboratory Tests on Paint System

Accelerated weathering Colour change/fastness

Loss of gloss

Physical change on paint film

Dilution

EXTERNAL

Adulteration

Purpose Emulsion-based

Enamel-based

Others Method Purpose

In compliance with SS5 Ensure specified paint

film thickness and

integrity

Algae resistance Resistance to micro-biological

attack

Wet scrub abrasion Film durability

Non- volatile matter Compliance to specification

Drying time Compliance to specification

Adhesion Compliance to specification

Colour comparison Compliance to specification

Impact Compliance to specification

Hardness Compliance to specification

✓ ✓

✓

✓

✓ ✓ ✓

✓ ✓

✓ ✓

✓ ✓ ✓

✓

✓ ✓

Appendix C

appendix D43

Sample of Inspection and Test Plan

Project:

Scope of Work: Painting

Activity People-In-Charge

S/No InspectionMethod

RequirementReference

Acceptance Criteria Stages Records

SUBMISSION1

INCOMING MATERIALS INSPECTION2

Paint Type AP/SE/A/O1.1 Review Section 4.1 Approved Initial Approved submissions

Technical Data AP/SE/A1.2 Review – Approved Initial Approved submissions

Surface Preparation Method AP/SE/A1.3 Review Section 4.2 Approved Initial Approved submissions

Method Statement AP/SE/A1.4 Review – Approved Initial Approved submissions

Working Programme AP/SE/A/O1.5 Review – Approved Initial Approved submissions

Check Shelf Life AP/S/COW2.1 Visual Section 3.1 Conform to manufacturer’sdata sheet

Each delivery Delivery document

Check Colour AP/S/COW2.2 Visual Section 3.1 As per approved samples Each delivery Delivery document

Prepared by

Date

Verified by

Date

Approved by

Date

IN-PROCESS INSPECTION3

Check EnvironmentalConditions

AP/S/COW3.1 Visual/Measure Section 5.1 Conform to manufacturer’sdata sheet

Before coating Appendix E

Confirm Location ofApplication

AP/S/COW3.2 Visual Section 4.1 Conform to approvedsubmission


Confirm Surface PreparationMethod



Confirm Number of Coats AP/S/COW3.4 Visual Section 2.1/4.1 Conform to approvedsubmission


Confirm Name (Type) ofCoats

AP/S/COW3.5 Visual Section 2.1/4.1 Conform to approvedsubmission


LEGEND AP – Applicator S – Site Supervisor SE – Site Engineer COW – Clerk of Work O – Owner A – Architect

Appendix D

appendix D

44

Sample of Inspection and Test Plan (cont’d)

Project:

Scope of Work: Painting

Activity People-In-Charge

S/No InspectionMethod

RequirementReference

Acceptance Criteria Stages Records

IN-PROCESS INSPECTION (cont’d)3

Confirm Method ofApplication


Before Coating Appendix E

Check Substrate AP/S/COW3.7 Visual/Measure Section 4.2 Surface clean, stable and drySmoothness and flatness ofsubstrateSurface temperature


Check Protection Works AP/S/COW3.8 Visual Section 4.4 Protect adjacent elements (notto be painted)


Check Safety AP/S/COW3.9 Visual Section 4.5 Wear proper working attire,footwear, helmet & safety beltUse protective materials (mask,glasses) where necessaryErect proper access such asscaffold


Check Paint Mix AP/S/COW3.10 Visual Section 4.3 Conform to manufacturers’data sheet


Prepared by

Date

Verified by

Date

Approved by

Date

LEGEND AP – Applicator S – Site Supervisor SE – Site Engineer COW – Clerk of Work O – Owner A – Architect

Check Application Tools AP/S/COW3.11 Measure Section 5.2 Conform to approvedsubmission


Check Painting AP/S/COW3.12 Visual/Measure Section 5.5 Conform to manufacturers’data sheet

Before/ During Coating Appendix E

Test Site Sample (Random) AP/S/COW3.13 Visual/Lab Test Section 3.1/Appendix C

Conform to specification Before/ During Coating Appendix E

FINAL INSPECTION4

Check Protection Work AP/S/COW4.1 Visual Section 5.4 Protect completed work At Completion Appendix F

Work Acceptance AP/S/COW4.2 Visual/Measure Section 5.5 Conform to specification andapproved submission

At Completion Appendix F

Appendix D

Sample Checklist for In-Process Inspection on Painting Work(Concrete/Plaster Surface)

Project: Location:

Appendix E

appe

ndix

E

45

Checklist InspectionRequirementReference

Date

Surface Preparation

1. Fresh surface cured for 21 days (applicable to newcoating only)

2. Moisture level < 6% or refer to manufacturers’recommendations

3. Surface free from algae or fungus growth4. Surface free from unstable matters5. Surface free from grease or oil6. Exposed surface primed7. Substrate hairline cracks8. Type of stopper or filler used for deep holes or

shallow depressions

Table 4.1

Table 4.1

Table 4.1Table 4.1Table 4.1Table 4.1Table 4.1Table 4.1

Result Sign

Paint Preparation

9. Name, colour and type of paint10. Thinning ratio11. Mix ratio12. Pot-life

Section 4.3Section 4.3Section 4.3Section 4.3

Painting Environment

13. Surrounding temperature > 5°C or refer tomanufacturers’ recommendations

14. No strong wind15. Environment free from dust or pollutants16. Relative humidity17. Adequate ventilation18. Adequate lighting

Section 5.1

Section 5.1Section 5.1Section 5.1Section 4.5Section 4.5

Paint Application

19. No. of coats and location of application20. Adjacent elements (not to be painted) are protected21. Proper working attire, footwear, and helmet are worn22. Proper gloves, protective masks or glasses are worn

(where necessary)23. Safety belts and proper accesses are provided24. Surface clean and dry25. Surface temperature26. Appropriate application tools are used27. Painting frequency28. Painting interval29. Drying time30. Lab Test Submission


Section 4.5Section 4.2Section 5.1Section 5.2Section 5.1Section 5.1Section 5.1Section 3.1/Appendix C

Final

30. Protect completed painting works Section 5.4

Prepared byDate

Verified byDate

Approved byDate

appe

ndix

E

46

Appendix ESample Checklist for In-Process Inspection on Painting Work(Timber Surface)

Project: Location:


Date

Surface Preparation

1. Moisture level < 15% or refer to manufacturers’recommendation

2. Surface free from algae or fungus growth3. Surface free from unstable matters4. Exposed surface primed5. Substrate imperfections6. Type of stopper or filler used for deep holes or

shallow depressions

Table 4.2

Table 4.2Table 4.2Table 4.2Table 4.2Table 4.2

Result Sign

Paint Preparation






Section 5.1


Paint Application

17. No. of coats and location of application18. Adjacent elements (not to be painted) are protected19. Proper gloves, protective masks or glasses are worn

(where necessary)20. Proper working attire, footwear and helmet are worn21. Safety belts and proper accesses are provided22. Surface clean and dry23. Surface temperature24. Appropriate application tools are used25. Painting frequency26. Painting interval27. Drying time28. Lab Test Submission

Section 4.1Section 4.4Section 4.5

Section 4.5Section 4.5Section 4.2Section 5.1Section 5.2Section 5.1Section 5.1Section 5.1Section 3.1/Appendix C

Final


Prepared byDate

Verified byDate

Approved byDate

Sample Checklist for In-Process Inspection on Painting Work(Metal Surface)

Project: Location:

appe

ndix

E

47


Date

Surface Preparation

1. Surface free from rust2. Surface free from unstable matters3. Surface free from grease or oil4. Exposed surface primed

Table 4.3 & 4.4Table 4.3 & 4.4Table 4.3 & 4.4Table 4.3 & 4.4

Result Sign

Paint Preparation






Section 5.1


Paint Application

15. No. of coats and location of application16. Adjacent elements (not to be painted) are protected17. Proper working attire, footwear and helmet are worn18. Proper glove and protective masks or glasses are

worn (where necessary)19. Safety belts and proper accesses are provided20. Surface clean and dry21. Surface temperature22. Appropriate application tools are used23. Painting frequency24. Painting interval25. Drying time26. Lab. Test submission


Section 4.5Section 4.2Section 5.1Section 5.2Section 5.1Section 5.1Section 5.1Section 3.1/Appendix C

Final


Prepared byDate

Verified byDate

Approved byDate

Appendix E

appe

ndix

F

48

Sample Checklist for Final Inspection on Painting Work

Project: Location:


Date

1. Visual:• Color• Gloss• Texture (optional)

2. Adhesion

As per approvedsample

As per approvedsample

Result Sign

Prepared byDate

Verified byDate

Approved byDate

Appendix F

refe

renc

e

49

Reference

1. SS CP 22The Painting of Buildings

2. SS 5Methods of Test for Paints, Varnishes and Related Materials.

3. SS 7Paint: Finishing, Gloss Enamel

4. SS 34Undercoat paint for Gloss Enamel

5. SS 38Aluminium Wood Primer

6. SS 494Lead and Chromate-free Primer for Iron and Steel Substrates

7. SS 150Emulsion Paints for Decorative Purposes

8. SS 345Algae Resistant Emulsion Paint For Decorative Purposes

9. SS 500Elastomeric Wall Coatings

10. Swedish Standard for Abrasion SA 2.5

11. Swedish Standard for Wire-brushing ST 3.0

4. painting (second edition)

Documents