guide to standards and tolerances.pdf

Guide to Standardsand TolerancesFor home builders and renovators

FT242 July 2003

www.fairtrading.nsw.gov.au/building

Acknowledgments

This Guide was prepared in consultation with individuals representingvarious industry and consumer groups.The Office of Fair Tradingacknowledges and thanks the Housing Industry Association (Victoria) andthe Housing Guarantee Fund Ltd for their work in developing the first“Guide to standards and tolerances” in 1992.The Office of Fair Tradingalso acknowledges the subsequent work of

• Australian Institute of Building Surveyors

• Australian Society of Building Consultants

• Consumer Affairs Victoria

• Housing Guarantee Fund Ltd

• Housing Industry Association

• Insurance Council of Australia

• Master Builders Association of Victoria

• The Institution of Engineers (Australia)

• Building Commission Victoria

• Department of Infrastructure, Planning and Natural Resources

Additional copiesThis publication can be viewed or printed from the Publications page ofour Web site at: www.fairtrading.nsw.gov.au

Copies of this publication can be requested by calling 13 32 20.To orderquantities of more than five, fax a written request with your street address to

Fax: 9619 8618 or post to:Office of Fair TradingMarketing BranchPO Box 972Parramatta NSW 2124

Disclaimer

This publication is a plain language guide to your rights andresponsibilities. It must not be relied on as legal advice. For moreinformation please refer to the appropriate legislation or seek independentlegal advice.

ISBN 0 7347 6010 8

© Office of Fair Trading

Last revised July 2003

1NSW Office of Fair Trading Guide to Standards and Tolerances

The Guide to Standards and Tolerancesis a valuable tool to clarify areas ofbuilding standards that are notprescribed in legislation.

Generally a builder and a building owner,parties to a building contract, can agree toapply the building standards they considerappropriate to a building project. But theymay not agree to standards less than thoseprescribed by Government. Sometimes theagreed standards are detailed in the contractdocuments but often they are not.

The purpose of this Guide is to indicate theview of reasonable standards and tolerancesfor building work, where such standards andtolerances are not articulated by the contractdocuments and are not prescribed in:

• the Home Building Act 1989;

• the Home Building Regulation 1997;

• the Building Code of Australia (BCA); and

• the Australian Standards referenced in theBCA.

Where there is any contradiction ordifference between the Guide and theBCA, relevant legislation or thebuilding contract, the BCA, legislationor building contract will takeprecedence.

The standards and tolerances includingthose that relate to the passage of time areintended as a guide only.They may notapply to some building projects where thespecific circumstances of the project or thecontract conditions of that project requireor imply other standards or tolerances.

The commencement of any time periodmentioned in the Guide is to be taken fromthe date of the occupation certificate for abuilding project. Some information in thisGuide has been extracted from the BCA orreferenced Australian Standards to assistusers.

This document is intended to serve as ageneral guide only, and is always subject toprevailing legislation and regulations.

ntroductionI

2 Guide to Standards and Tolerances NSW Office of Fair Trading

1. Application . . . . . . . . . . . . . . . . .4

2. Appliances . . . . . . . . . . . . . . . . . .6

3. Masonry . . . . . . . . . . . . . . . . . . . . .6

Definition of masonry . . . . . . . . . .6

Masonry distress . . . . . . . . . . . . . .6

Bed joints and perpends . . . . . . .6

Masonry facing . . . . . . . . . . . . . . . .6

Mortar . . . . . . . . . . . . . . . . . . . . . . . .7

Masonry voids . . . . . . . . . . . . . . . . .7

Damproof courses . . . . . . . . . . . . . .7Raking of joints . . . . . . . . . . . . . . .7

Brick Sills – Shrinkage allowancefor timber framing . . . . . . . . . . . . . .7

Flashings . . . . . . . . . . . . . . . . . . . . . .8

General . . . . . . . . . . . . . . . . . . . . . . .8

Timber frames . . . . . . . . . . . . . . . . .8

Aluminium frames . . . . . . . . . . . . .8

Render and applied finishes for masonry . . . . . . . . . . . . . . . . . . .8

Cracking . . . . . . . . . . . . . . . . . . . . . .8

Matching colour and texture . . .8

Cracking at articulation joints . . .8

4. Concrete slab distress . . . .9

5. Condensation . . . . . . . . . . . . .10

6. Doors . . . . . . . . . . . . . . . . . . . . . . .10

Door handles and latches . . . . .10

Doors and door frames . . . . . . . .10

Internal doors . . . . . . . . . . . . . . . .10

External doors . . . . . . . . . . . . . . . .10

General . . . . . . . . . . . . . . . . . . . . . .10

7. Lightweight substrate with applied finishes . . . . .11

8. External mouldings . . . . . . .11

9. Articulation joints . . . . . . . .11

10. Internal fixing . . . . . . . . . . . . .11

11. Floor and wall tiling . . . . . .11

General . . . . . . . . . . . . . . . . . . . . . .11

Tile matching . . . . . . . . . . . . . . . . .11

Tiling workmanship . . . . . . . . . . .12

12. Floors . . . . . . . . . . . . . . . . . . . . . .12

Gaps in enclosed timber flooring . . . . . . . . . . . . . . . .12

Plywood and particle board flooring . . . . . . . . . . . . . . . .12

Nail popping . . . . . . . . . . . . . . . . . .12

Squeaking floors . . . . . . . . . . . . . .12

Floor levels – concrete and timber – as built . . . . . . . . . .12

13. Footings and foundations . . . . . . . . . . . . . . . .13

General . . . . . . . . . . . . . . . . . . . . . .13

Foundation and site drainage – maintenance . . . . . . .13

Distress . . . . . . . . . . . . . . . . . . . . . .13

14. Glazing . . . . . . . . . . . . . . . . . . . . .13

15. Lyctus borer . . . . . . . . . . . . . . .14

16. Painting . . . . . . . . . . . . . . . . . . . .14

17. Paving & driveways . . . . . .14

ontentsC


18. Plasterboard . . . . . . . . . . . . . .15

General . . . . . . . . . . . . . . . . . . . . . .15

Peaking or jointing . . . . . . . . . . . .15

Plasterboard cracking . . . . . . . . .15

Nail popping . . . . . . . . . . . . . . . . . .15

Matching existing plaster and texture . . . . . . . . . . . .15

19. Hard plaster . . . . . . . . . . . . . . .15

20. Restumping works . . . . . . .15

Consequential damage . . . . . . . .15

Floor levels . . . . . . . . . . . . . . . . . . .15

Packing material . . . . . . . . . . . . . .15

21. Roofing systems . . . . . . . . . .16

Metal roofing/components . . . .16

Pointing . . . . . . . . . . . . . . . . . . . . . .16

Roof batten alignment . . . . . . . . .16

Roof batten spacing . . . . . . . . . . .16

Dry valley construction . . . . . . . .16

Undulating roof lines . . . . . . . . . .16

22. Shower enclosures . . . . . . .16

Shower screens . . . . . . . . . . . . . .16

Shower bases . . . . . . . . . . . . . . . .16

23. Gutters and downpipes . .16

24. Steel framing . . . . . . . . . . . . . .16

25. Stormwater systems . . . . .17

26. Straightness/plumbness of walls . . . . . . . . . . . . . . . . . . . . .17

27. Termites (white ants) . . . . .17

28. Timber shrinkage and splitting . . . . . . . . . . . . . . .17

29. Water hammer . . . . . . . . . . . .17

30. Water leaks . . . . . . . . . . . . . . . .17

Appendix A

Interpretation of ± tolerances given in Australian Standards Codes . . . . .18

Appendix B

Engineering diagrams explainingcontent of table in clause 3.3 – Bed joints and perpends relating to AS 3700 - 2001 Masonry structures .19


1. ApplicationThe primary obligation of the holder of acontractor licence (licensee) issued underthe Home Building Act 1989 (the Act) is tocarry out residential building work inaccordance with the Act, as detailed in anyplans and specifications which form part ofthe contract. Further, as set out in Part 2Cof the Act, statutory warranties are impliedin every contract to do residential buildingwork.

The contractual obligations and thestatutory warranties require levels ofperformance from the licensee.Theminimum levels of acceptable performanceare normally set out in the buildingcontract and the relevant building codesand standards in force at the time.Nevertheless, there are some particulars ofperformance that are not specified in any ofthese documents. It is the purpose of thisGuide to indicate levels of performancewhich are considered acceptable by theOffice of Fair Trading as well as assistbuilders and owners with matterscommonly the subject of dispute.

The standards and tolerances referred to inthis Guide only relate where the ‘Deemed-to-Satisfy” provisions of the Building Code ofAustralia (BCA) have been applied.Reference to the BCA in this Guide is tothe Building Code of Australia 1996, Volume2, Class 1 and Class 10 Buildings (HousingProvisions).The standards and tolerances inthis Guide may not be applicable where aresidential building contract involves theuse of the performance standard of theBCA. However, this does not relieve thelicensee from attaining any performancelevel required by the applicable buildingcodes and standards.

This Guide does not provide standards andtolerances for Class 2 residential buildings.However in some cases the AustralianStandards referenced in this Guide maycontain standards and tolerances for thosebuildings.

Where there is any contradiction ordifference between the Guide and theBCA, relevant legislation or the buildingcontract, the BCA, legislation or buildingcontract will take precedence.

Timing is sometimes an issue. Constructionthat may be considered a defect whenobserved soon after the building work iscomplete may be considered fair wear andtear sometime later. Building contractsnormally include a defects liability clausespecifying a period after completion whenthe builder will rectify defects that becomeapparent in that period.

Fittings and equipment are often supportedby manufacturers’ warranties.The defectsliability period stated in a contract andmanufacturers’ warranties should beconsidered in association with this Guide.

Fair Trading recognises the dynamic natureof the residential building industry and toensure acceptable practice and competencythroughout the industry, it will regularlyreview this Guide.

Most Australian Standards that arereferenced in this Guide are referenced inthe BCA.The Standards are indicated byeither “AS” or “AS/NZS” followed by theappropriate reference number, whichincludes the year of publication.

The tolerances specified herein are notapplicable where second hand materials andproducts are proposed to be used with thestructure of a new building, i.e. door andwindow clearance tolerances.

The Building Code of Australia

The primary vehicle responsible for settingstandards for the design and construction ofbuildings is the Building Code of Australia(BCA) and its referenced documents.

The BCA is given legal effect in NSWthrough the Environmental Planning &Assessment Act 1979 (EP&A Act) and theEP&A Regulation 2000.The EP&A Actprovides that all development consents are

DefinitionsA Class 1 building is a single dwelling or a row of townhouses/terraces/villas joined by a fire resisting wall.A Class 10 building is a non-habitable building/structure such as a garage/car port/shed/fence/swimming pool.A Class 2 building is a high rise building containing two or more separate dwellings located one above the other.


subject to a prescribed condition thatdevelopments involving building workmust be carried out in accordance with therequirements of the BCA.

A complying development certificate and aconstruction certificate, which approves thedetailed design plans, can only be issued forbuilding work if the certifying authority issatisfied that the proposed building willcomply with the BCA, whether by the‘deemed-to-satisfy’ or performance path.

Before an occupation certificate for abuilding can be issued, the EP&ARegulation requires that the certifyingauthority be satisfied that, among otherthings, the building is suitable foroccupation or use in accordance with itsclassification under the BCA.

The goals of the BCA are to enable theachievement of acceptable standards ofstructural sufficiency, safety (including safetyfrom fire), health and amenity for thebenefit of the community now and in thefuture. These goals are applied so that theBCA extends no further than is necessaryin the public interest, is cost effective, andnot needlessly onerous in its application.

The BCA therefore sets minimumacceptable standards for the design and

construction of buildings. Consentauthorities in NSW, however, may requiremore than the BCA when circumstanceswarrant. It is not possible for a consentauthority to specify a lower standard thanthe BCA.

The BCA contains technical provisions formatters such as structural sufficiency, firesafety, access for people with disabilities, safemovement, and health and amenity. Thesecover subjects such as damp andweatherproofing, light and ventilation,sanitary facilities, and sound insulation.

The BCA was converted to a fullyperformance based code in 1996 (BCA96).For each section of the BCA there is aseries of statements expressing what abuilding must achieve in terms of itsperformance (i.e. the performancerequirements). These provisions areaccompanied by a set of prescriptiveprovisions that are ‘deemed-to-satisfy’ theperformance requirements.An owner orapplicant may choose to comply with thedeemed-to-satisfy (DTS) provisions or maydevelop an alternative building solution thatsatisfies the performance requirements, or acombination of both.

Guidance

Compliance

Building Solutions

Deemed-to-satisfy provisions (DTS)NB. Conclusive proof of compliance

Alternative Solutions

Objectives

Functional Statements

Performance Requirements

BCA 96 – Structure


2. AppliancesDefects occurring in appliances and/orfixtures will only be considered thebuilder’s liability if the actions of thebuilder have contributed to the defect.

3. Masonry Definition of masonry

The following definition of “Masonry” hasbeen extracted from AS 3700 – 2001Masonry Structures.

“Scope

This Standard sets out minimumrequirements for the design andconstruction of masonry, includingunreinforced, reinforced and prestressed,using manufactured units of clay, calciumsilicate and concrete laid in mortar,autoclaved aerated concrete (AAC) laid inthin-bed mortar, and square-dressed naturalstone laid in mortar.

The Standard does not give values ormaterial properties for the design andconstruction of square-dressed naturalstone.

Notes:

1. This Standard assumes that the structuraldesign of masonry is entrusted toexperienced structural engineers orsimilar appropriately qualified persons,and that the execution of such work iscarried out under the direction ofappropriately qualified persons who areexperienced in masonry constructionand who understand the structuralrequirements.

2. The Standard does not give specificrequirements for prefabricated masonrypanels or masonry in composite actionwith steel or concrete structuralmembers.The principles of this Standardshould be followed, as far as they areapplicable, for such types of construction.

3. The provisions of this Standard do notinclude specification for design andconstruction of AAC laid in other thanthin-bed mortar. However, for masonryso constructed the general principles ofthis Standard may be used.”

Masonry distress

Where distress is rated at Category 3 ormore (i.e. more than 5mm; refer AS 2870 -1996 Residential Slab & FootingsConstruction), appropriate rectificationworks will be required. If distress isCategory 2 (between 1mm to less than5mm) it is considered a defect, however,minor repairs would be acceptable e.g.repointing.

Refer to Table C1 in Clause 4 “ConcreteSlab Distress”.

Refer to Notes in Table C2 in Clause 4“Concrete Slab Distress”.

Bed joints and perpends

Where masonry matching is no longerappropriate a practical approach may beadopted in the case of renovations and oradditions.


Notes:

1. Items H, I, J & K are not applicable tothin-bed mortar joints.

2. Items I & J are not applicable whenperpend joints are not filled with mortaras is the case with some horizontallycored masonry that is not required toresist horizontal bending.

See Appendix B for diagrams explainingcontent of above table.

Masonry facing

Bricks shall generally be laid with truebrick face outwards. Brick faces shall becleaned and free of excess mortar unlessotherwise specified.

When bricks in batches supplied frommanufacturers vary in colour, they shall bemixed/distributed in accordance with

manufacturers recommendations unlessotherwise specified.

Mortar

Mortar shall generally be mixed inaccordance with the requirements of theBCA as applicable. Part 3.3.1 (Clauses3.3.1.6 and 3.3.1.7)

Masonry voids

Where masonry construction or cleaningresults in obvious holes exceptingweepholes, these are deemed to be a defect.

Making good is to be carried out so thatany repair or the like is as close aspractically possible to the existing mortar.

Damproof courses

To be in accordance with the Part 3.3.4 ofthe BCA.

Table 11.1 AS 3700 - 2001 – Masonry Structures

Item Structural tolerance Non-structuralfacework tolerance

A Horizontal position of any masonry ±15mm ±15mmelement specified or shown in plan at its base or at each storey level

B Relative displacement between ±10mm ±10mmload-bearing walls in adjacent storeys intended to be in vertical alignment

C Maximum deviation from plumb within The lesser of ±10mm ±10mma storey from a vertical line through the per 3 m of height base of the member or 0.05 times the

thickness of the leaf

D Maximum deviation from plumb in the ±25mm ±25mmtotal height of the building (from the base)

E Maximum horizontal or vertical deviation ±5mm ±3mmof a surface from a plane surface (bow) when measured as described in Clause 11.5.2

F Deviation (step) of any exposed brick Not applicable 2mmsurface from any adjacent exposed brick surface. The bow provision of Item (E) above also applies

G Deviation of bed joint from horizontal, ±10mm in any ±10mm in anyor from the level specified or shown 10 m length, 10 m length, in elevation ±15mm in total ±15mm in total

H Deviation from specified thickness of bed joint ±3mm ±3mm

I Minimum perpend thickness 5mm 5mm

J Deviation from specified thickness +10mm maximum ±5mm averageof perpend

K Maximum difference in perpend thickness No limit 8mmin any wall

L Deviation from specified width of cavity ±15mm ±15mm


Raking of joints

Raking of mortar joints in masonry unitsshall not exceed 10mm depth and beconsistent throughout. Mortar joints andthe raking of mortar joints is to be inaccordance with the Part 3.3.1 (Clause3.3.1.7) of the BCA.

Brick sills – shrinkageallowance for timber framing

Reference to brick sills includes for sill tiles.

Distortion of window frames and ordislodgment of sill bricks shall be a defectwhere such distortion and or dislodgmentwas caused by lack of initial sill brickclearance from the window sill refer to Part3.3.1 of the BCA.

In masonry veneer walls a gap must be leftbetween the timber frame and the top ofthe masonry wall, including window sillsetc, to allow for initial settlement of thetimber framing caused by timber shrinkage.These clearances must be provided at thetime of construction and must not be notless than-

(i) 5mm at sills of lower and single storeywindows; and

(ii)8mm at roof overhangs of single storeybuildings; and

(iii)10mm at sills of second storey windows;and

(iv)12mm at roof overhangs to two storeybuildings.

The clearances described in (i)-(iv) abovemust be doubled if the timber framing isunseasoned hardwood.

Flashings

General

Flashings shall be provided in accordancewith the requirements of the Part 3.5.3 WallCladding (Clause 3.5.3.6) and Part 3.3.4Masonry, of the BCA.

Timber frames

Flashings should be provided to all timberwindows in accordance with the Part 3.5.3of the BCA and/or manufacturer’sspecifications to prevent ingress of rain ormoisture from reaching the inner face of awall.

Aluminium frames

Aluminium windows and doors shall beinstalled according to manufacturer’sspecifications unless otherwise specified.

Render and applied finishesfor masonry

Cracking

Cracking of finishes to be assessed inaccordance with Section 3 MasonryDistress. Obvious spot rust marks due to thecomposition of the material is considered adefect.

Matching colour and texture

When matching a finish, a practicalapproach must be adopted, and wherepossible a physical joint, a door/window,downpipe or other similar separatingmaterials be incorporated.The purpose ofthis is to “break” the visual impact.

The builder should make every effort tomatch existing so as to be as close to amatch as possible, where this is practicable.In some instances this may not be practicalas the original finish may have significantlyaged or chemical additives may have beenused which are impossible to determinewithout expensive research.

Cracking at articulation joints

Provision for the control of cracking inarticulation joints should be allowed for orotherwise specified.

If the owner or agent at the time ofconstruction specifies construction thatdoes not allow for movement, cracking willnot be considered a defect.


4. Concrete slabdistressIf distress is rated at less than Category 3,the defect is to be monitored for a periodof twelve months. If, at the end of themonitoring period, the distress rating isassessed as greater than Category 2, this will

be considered a defect. Where a residentialslab designed in accordance with AS 2870- 1996 or AS3600 – 2001 Concretestructures is to act as a termite barrier inaccordance with AS 3660 – 2000 Termitemanagement, shrinkage cracks through theslab are not to exceed 1.0 mm in width.

Extract from AS2870-1996 – Residential slabs and footings – constructionTable C1 Classification of damage with reference to walls (Appendix C of AS 2870 -1996)

Description of typical damage Approximate crack width limit Damage categoryand required repair (see Note 3)

Hairline cracks < 0.1mm 0

Fine cracks which do not need repair < 1mm 1

Cracks noticeable but easily filled

Doors and windows stick slightly < 5mm 2

Cracks can be repaired and possibly 5mm to 15mm 3a small amount of wall will need to be (or a number of cracks replaced. Doors and windows stick. 3mm or more in one group)Service pipes can fracture. Weather tightness often impaired.

Extensive repair work involving 15mm to 25mm but also 4breaking-out and replacing sections depends on number of cracks.of walls, especially over doors and windows. Window and door frames distort. Walls lean or bulge noticeably, some loss of bearing in beams. Service pipes disrupted.

Table C2 Classification of damage with reference to concrete floors (Appendix C of AS 2870 -1996)

Description of Approximate crack Change in offset from Damage typical damage width limit a 3m straight edge category

centred over defect (see Note 6)

Hairline cracks, insignificant <0.3mm <8mm 0movement of slab from level.

Fine but noticeable cracks. <1.0mm <10mm 1Slab reasonably level.

Distinct cracks. Slab noticeably <2.0mm <15mm 2curved or changed in level.

Wide cracks. Obvious curvature 2mm to 4mm 15mm to 25mm 3or change in level.

Gaps in slab. Disturbing curvature 4mm to 10mm >25mm 4or change in level.

Notes:

1 Crack width is the main factor by whichdamage to walls is categorised.The widthmay be supplemented by other factors,including serviceability, in assessingcategory of damage.

2 In assessing the degree of damage,account shall be taken of the location in

the building or structure where it occurs,and also of the function of the buildingor structure.

3 Where the cracking occurs in easilyrepaired plasterboard or similar clad-framed partitions, the crack width limitsmay be increased by 50% for eachdamage category.


4 Local deviation of slope, from thehorizontal or vertical, of more than1/100 will normally be clearly visible.Overall deviations in excess of 1/150 areundesirable.

5 Account shall be taken of the past historyof damage in order to assess whether it isstable or likely to increase.

6 The straight edge is centred over thedefect, usually, and supported at its endsby equal height spacers.The change inoffset is then measured relative to thisstraight edge.

5. CondensationCondensation on walls, windows and inbathrooms can be caused by conditionsbeyond the builder’s control and will notusually be considered a defect.

Roof condensation will be considered adefect if caused by incorrect positioning ofsarking, or vapour barrier where installed.The effects of condensation will not beconsidered a defect if the builder hascomplied with the requirements of theBCA.

6. DoorsDoor handles and latches

Door handles and latches installed shall befit for purpose and will operate as intendedby the manufacturer. Defects occurring inthe first three months of completion shallbe the responsibility of the builder.Thereafter defects occurring will only beconsidered the builder’s liability if theactions of the building have contributed tothe defect.

Doors and door frames

This clause only applies to the 3 monthsmaintenance period as specified under thecontract.

Internal doors

Unless specified in the contract, or wherean increased clearance is required for:

• removable toilet doors;

• return air ventilation for ducted heatingor air-conditioning units;

• inlet ventilation to rooms where the onlyventilation is provided by ventilatedskylights and/or exhaust fans;

• between double swing doors and Frenchdoors.

Within the first three months, an even gapto the sides and top of individual doorsshall be consistent throughout, to within1mm and shall be not less than 2mm orexceed 5mm wide and a maximum gap of20mm between the bottom of the door andthe top of any finished floor covering unlessotherwise specified.

External doors

External doors shall be appropriate for theirintended purpose and shall be installed inaccordance with the manufacturer’srecommendations.

General

Tolerances for twisting and bending in thefirst three months are as listed below.

1. Twist

Twist in a door shall not exceed 5mm.

2. Bending

Bending in a door shall not exceed thefollowing:

(a)In the height of the door:

(i) up to and including 2150mm high– 4mm, or

(ii)over 2150mm and up to andincluding 2400mm high – 6mm.

(b)In the width of the doors up to andincluding 1020mm wide – 2mm.

Doors which bind or jam, as a result of thebuilder’s work, shall be considered defects.


7. Lightweightsubstrate withapplied finishesApplied finishes (excluding painting) tolightweight sheet substrate that havecracking or open joints greater than 1mmwill be considered a defect within the first12 months.

8. ExternalmouldingsCracking at joints or in external mouldingsand architectural features greater than 2mmwill be considered a defect within the first12 months.

9. Articulation jointsProvision for the control of cracking inarticulation joints should be allowed for orotherwise specified.


10. Internal fixingOnly gaps between mouldings, andbetween mouldings and other fixtureswhich exceed 1mm within the first 12 months will be considered defects.

11. Floor and wall tiling11.1 General

Tiling will be considered defective where:

(a)The builder supplied, laid andconstructed the sub-strata for the tiles; and

(i) any of the materials are defective,and/or

(ii)the application of adhesive, tiles orbacking sheet is not carried out inaccordance with manufacturer’sinstructions, and/or

(iii)there is unsatisfactory workmanshipbeneath the tiling system.

(b)The owner supplied materials andthe builder laid the tiles and carriedout preparatory works, and

(i) any materials not supplied by theowner are defective, and/or

(ii)application of adhesive, tiles orbacking sheets is not carried out inaccordance with manufacturer’sinstructions, and/or

(iii) there is unsatisfactory workmanshipbeneath the tiling system.

(c)The owner supplied and laid thetiles and the builder carried outpreparatory works other than thetile laying, and there isunsatisfactory workmanshipbeneath the tiling system (e.g. faultystud work and trimming, noggingwork, or concrete slab failure)

Where the owner installs the substrate, it isthe owner’s responsibility to ensure that thesubstrate has been installed in accordancewith the manufacturer’s instructions andthat the framing is satisfactory for the fixingof the substrate.

Cracked, loose or drummy tiles will beconsidered a defect if the cause is attributedto the builder. Subject to the above, theseitems will only be considered a defect ifmore than 10% of the tiled room or area isaffected, whichever is applicable.

Where the owner lays and supplies floortiles that are defective (i.e. cracked or loose)using a method of tiling application,adhesive and/or bedding not in conformitywith the manufacturer’s instructions, thenthe builder’s liability would only extend towhere consequential damage had occurreddue to the concrete slab distress as specifiedin this document.The owner has to provethe damage is attributable to the builder.The onus of proof is on the owner.

Tile matching

Where tile matching is no longer possible, apractical approach must be adopted andwhere possible, a slightly different tile maybe used.A tile separation joint may be


provided – for example, by means of analuminium channel of the shower screen,separating doorway, intersecting wall,change in wall direction or similar.

Tiling workmanship

Abutting tiles shall be flush excepting forany distortion inherent in the manufactureof the supplied tiles. Grout lines/widths totiling should be consistent as far aspracticable unless otherwise specified.

12. FloorsFlooring is to be installed in accordancewith Part 3.4 of the BCA.

Gaps in exposed timberflooring

The effects of sunlight, heating or otherheat generating appliances are to be takeninto consideration and if it is determinedthat they have contributed to the higherrate of shrinkage, then it is not considered adefect.

A gap of more than 2mm between adjacentboards will be considered a defect.

A total measurement of gaps between fourconsecutive boards in timber strip flooringof more than 5mm is a defect in areas otherthan those which may be affected by directsunlight, heating or other heat generatingappliances.

The builder shall not be liable for gapsconsidered as defects where the builder hasmade the owners aware, as acknowledgedby them in writing, that the flooring systeminstalled could suffer significant shrinkageleading to visually obvious movementresulting in gaps well in excess of thetolerances listed above.

If only one gap exists that is defectivewithin the meaning of this section, and itextends over 1 metre in length, it isconsidered a defect.

Plywood and particle boardflooring

Plywood and particle board flooring will beinstalled in accordance with Part 3.4 of theBCA and/or the manufacturer’srecommendations and data sheets.

Where swelling occurs at joints to such anextent that it can be detected throughnormal floor coverings then it will beconsidered a defect.

Nail popping

If in timber floors nail heads can bedetected through floor coverings or nailpopping is clearly visible in exposedflooring, this will only be considered adefect if occurring within the first 24months and only where the builder laid thefloor covering or polished the floor as partof the contract.

Where owners have polished exposedflooring or laid floor coverings aftercompletion of the builder’s works, dueconsideration shall be given by the owners,in regards to the effects of shrinkage of thefloor frame and the subsequent effects ofnail popping.

Squeaking floors

If floors squeak in trafficable areas withinthe first 24 months then a defect exists.Normal timber shrinkage is not consideredunsatisfactory workmanship of the builder.

Floor levels – concrete andtimber – as built

Generally, the floor is to be within ±10mmof level over the entire room and at alltimes, within ±5mm of level over any 3metre length within the first 24 months.

1.5m

1.7m

Glass

Elevation


13. Footings andfoundationsGeneral

Natural movements of the site soils shallnot exceed the parameters as outlined inAS 2870-1996. Surface movements shall beapplicable to the site classification asidentified by foundation data.

Foundation movements which are theresult of localised drying caused by theeffects of trees or excessive wetting causedby unsatisfactory workmanship or lack ofsite drainage by the builder will beconsidered a defect.

Foundation and site drainage – maintenance

Where defects have been caused by the lackof proper maintenance of foundationsand/or site drainage (where not theresponsibility of the builder) such defectsshall not be attributed to unsatisfactoryworkmanship.The CSIRO publicationGuide to Home Owners on FoundationMaintenance and Footing Performance (August1996) shall be used as a guide.

Distress

Where natural movements of the soil donot exceed the parameters as referenced inAS 2870 -1996 and where suchmovements have caused distress to thefabric of the building, this will be

considered to be a defect unlessconstruction methods done in aworkmanlike manner were adopted toaccommodate those movements, such as theprovision of isolation or movements joints.

14. GlazingScratched, fractured, chipped or blemishedglazing which has resulted from thebuilder’s unsatisfactory workmanship willbe considered a defect.

Assessment is to be based on the following:

• Scratches, fractures, chips or blemishesmust be visible when viewed internally,from a line of sight measured 1.7m abovethe finished floor, and a minimumdistance of 1.5m perpendicular to theface of the glass (see diagram) in normaldaylight conditions.

• Minor scratches, fractures, chips orblemishes within 5mm of glass edge willnot be deemed a defect. Minor is lessthan 10mm in length and not more than3 per panel.

Glazing is to be installed in accordancewith Part 3.6 of the BCA.


15. Lyctus borerEvidence of Lyctus borer will not beconsidered a defect. This borer attacks thesapwood part of hardwoods.

16. PaintingCoatings used are to be suitable for therelevant conditions and relevant wear andtear.They are to be applied in aworkmanlike manner and to manufacturer’sinstructions unless otherwise specified.

The minimum durability e.g. lifting,blistering, flaking etc. required is as follows:

• Exterior finishes

- Acrylics – 3 years

- Enamel – 2 years

- Semi transparent stains – 1 year

- Clear finishes – not recommended

• Interior finishes

- Acrylics, enamels, stains and clearfinishes – 3 years

17. Paving anddrivewaysFor verandahs, carports, paving, patios,driveways etc; any uncontrolled cracking ofconcrete will be considered a defect if thebuilder did not make allowance forshrinkage or general movement of theconcrete (i.e. slip joints around verandahposts, control joints, isolation joints etc.) orwhere uncontrolled cracking is the result ofunsatisfactory workmanship.

Cracking resulting from causes notattributable to unsatisfactory workmanship(e.g. trees planted too close to paving,commercial/heavy vehicle traffic, use ofsprinkler systems etc.) are not a defect.

Cracking resulting from trees planted orsprinkler systems installed by others afterconstruction and not part of the builder’sobligations are not a defect.

Notes:

1. The figures in the table below areadditional to the construction tolerancesused at the time of construction.

2. The design profile is centred over thedefect and supported at its ends by equalheight spacers.The change in offset isthen measured relative to this designprofile.

3. Shrinkage cracking in reactive subgradescan lead to loss of bedding sand undersegmental pavements.A geotextileseparation layer will prevent sand fromentering the shrinkage cracks.

4. Cracking in this context applies tobound pavements and not to segmentalpavements.

5. The stepping criterion applies only tosteps within the surface of the mainpavement. It shall not be applied wherethe main pavement abuts other structuressuch as edging, drainage pits, service pits,minor pavements (such as a pathwayadjacent to a driveway) and pavementsconstructed with materials of a differenttype.

AS3727 -1993 Table 1 – Performance Criteria

Condition Measure Limit

Cracking in bound pavements Crack width ≤1.5mm

Subsidence Offset under 1.5 m length of the ≤15mmdesign profile (See Note 2 above)

Stepping Relative surface level of adjacent ≤5mmpaving elements within the expanse

of the main pavement.


18. PlasterboardGeneral

Installation and jointing of plasterboard willconform with the manufacturer’srecommendations and data sheets.

Peaking or jointing

If plaster peaking or jointing is obvious innormal daylight conditions, it will beconsidered a defect. CSIRO Report No L8(1960) Illumination and decoration of flatsurfaces will be used as a guide.

Plaster board cracking

(a)Cracking less than 1mm is not a defectexcept where such cracking occurs inrecessed and butt joints.

(b)Diagonal cracking, except for cracks lessthan 1mm, will be considered a defectand the cause will be investigated.

Nail popping

Nail popping will be considered a defectwithin the first 24 months only if evidenceexists that such is caused by unsatisfactoryworkmanship. Normal timber shrinkage isnot considered to be unsatisfactoryworkmanship of the builder.

Matching existing plaster and texture

Refer to Section 3 – Matching Colour andTexture (Masonry).

19. Hard plasterCracking of more than 1mm will beconsidered a defect in rendered finishes.

Provision for the control of cracking inarticulation joints should be allowed for orotherwise specified.


20. RestumpingworksConsequential damage

The builder will not be responsible for anyconsequential damage caused by thebuilder’s restumping, if the builder canshow in writing, signed by the owner, thatthe owners had been sufficiently informedby the builder of the likelihood and natureof such consequential damage arising as aresult of the builder’s restumping works.

Notwithstanding the above, the builder willbe responsible for consequential damagecaused by unsatisfactory workmanship.

Floor levels

Re-levelling of the floor levels within anexisting dwelling shall be within ±15mmover any room unless physical or statutoryrestrictions exist.

Re-levelling of existing structures shall becarried out having regard to limitationsimposed by:

• existing structural conditions

• fixed points

• attached buildings

• extensions to the dwelling

• plumbing installations

• or any other factor which may restrictthe re-levelling process.

Packing material

Packing material should be a suitable non-compressible material.


21. Roofing systemsMetal roofing/components

Installation will be in accordance with themanufacturer’s recommendations and datasheets and in accordance with Part 3.5.1 ofthe BCA (Clause 3.5.1.3).

Rectification of pre-colour coatedcomponents shall be carried out inaccordance with the manufacturer’srecommendations.

Tiled roofing

The installation of roof tiling is to be inaccordance with Part 3.5.1 of the BCA(Clause 3.5.1.2).

Pointing

If pointing becomes dislodged or washedout, it will be a defect if caused byunsatisfactory workmanship or materials.Minor cracking of pointing is not a defect.

Roof batten alignment

Battens shall be aligned to within atolerance of ±20mm in 4m. Refer to AS 2050 -1995 Installation of roof tiles.

Refer to Appendix A for an illustrativeexample of the interpretation of tolerances.

Roof batten spacing

Spacing of tiling battens shall be inaccordance with manufacturer’srequirements. However AS 2050 -1995allows a tolerance of ±5mm.

Battens over 75mm in thickness shall beblocked or otherwise restrained fromoverturning. (Refer to AS 2050 -1995).

Undulating roof lines

Undulations due to unsatisfactoryworkmanship or loose truss chords will beconsidered a defect when the deflectionexceeds ±20mm in any 4m length.

Notwithstanding, consideration shall begiven to the effects of long term deflectionof roof frame members.

Refer to Appendix A for an illustrativeexample of the interpretation of tolerances.

22. ShowerenclosuresShower screens

Fair wear and tear of shower screencomponents will not be considered adefect. Cracking of shower screens andcracking of shower glass will not beconsidered to be a defect where suchcracking has been caused by factors otherthan unsatisfactory workmanship or amanufacturing process. The installation ofshower doors, shower screens and bathenclosures is to be in accordance with Part3.6 of the BCA (Clause 3.6.9).

Shower bases

The installation of shower bases is to be inaccordance with Part 3.8 of the BCA.Shower bases which crack, leak or do notperform as intended will not be consideredto be a defect where such cracking hasbeen caused by factors other thanunsatisfactory workmanship or amanufacturing process.

23. Gutters anddownpipesGenerally gutters shall not retain more than10mm of water. Leaking of joints in guttersmay be considered a defect where suchdefect has been caused by unsatisfactoryworkmanship.

24. Steel framingSteel framing is to be installed inaccordance with Part 3.4.2 of the BCA.Steel framing shall be suitable for theparticular application and installed inaccordance with the manufacturer’sspecifications.Where defects arise due tothe effects of thermal/structural movementsof the framing members and no allowancehas been made for such movements thenthe consequential damage shall beattributed to the builder’s unsatisfactoryworkmanship.


25. StormwatersystemsStormwater systems are to be installed inaccordance with Part 3.1.2 and Part 3.5.2of the BCA. Stormwater drainage systemsshall function as intended.Wherestormwater drainage systems fail to performas intended and the failure is attributable tounsatisfactory workmanship, then a defectexists.

Defects caused by factors beyond thebuilder’s control such as intrusion of treeroots etc will not be attributed tounsatisfactory workmanship.

Where new stormwater systems areconnected to existing stormwater drainagesystems in the case of renovations oradditions, then unless the contract allowsfor any works to the existing system thebuilder shall only be liable for any defectsthat arise for works carried out under thecontract.

26. Straightness/plumbness of wallsGenerally walls are to be within ±5mmfrom the vertical over any 3 metre height.Refer to Appendix A for an illustrativeexample of the interpretation of tolerances.

27. Termites (white ants)Evidence of termites will not be considereda defect in areas not designated by localcouncils as termite prone areas.

In termite designated areas, evidence oftermite activity will be considered a defectif the builder did not comply with theTermite Risk Management Requirementslisted in Part 3.1.3 of the BCA, unless therelevant building authority approvedotherwise.

28. Timbershrinkage andsplittingUp to 10% shrinkage will be accepted forunseasoned timber. For seasoned timbers, amaximum of 3% shrinkage will beaccepted.

Timber stairs may have the followingtolerances, and not be considered a defect,when applied where conditions such asmovement of materials due to atmosphericmoisture changes (i.e. cupping of timberstair treads) affect finished stair dimensions.

• Variation in the tread/going no greaterthan 5mm

• Variation in a riser height no greaterthan 5mm.

These tolerances should not be applied toallow poor construction practice.

29. Water hammerAny water hammer is a defect.

30. Water leaksRoofs, gutters, flashings, skylights, windowframe joints or window seals which leakunder normal weather conditions for theparticular terrain, will be considered adefect.

A defect will not exist if the roofing systemhas not been regularly maintained by theowner or where the owner has failed tomaintain the protective coating system totimber window frames.


Appendix AInterpretation of ± tolerances given in Australian StandardsCodes.

Introduction: some tolerances that occur in the Guide to Standards and Tolerances areexpressed in terms of ± measurements.The question of the definition of this terminologyhas not been addressed.

This Appendix seeks to provide this definition.This advice has been prepared inconsultation with Standards Australia.

Case examples: for a tolerance of +_ 5mm over 3 metres

(A) Less than or equal to 5mm

Subject wall

≤ 5mm ≤ 5mm

≤ 5mm

3m 3m

(B) Less than or equal to 5mm

Case (B) is acceptable

This element is ≤ 5mmout of vertical

Case (A) is acceptable


Appendix BEngineering Diagrams explaining content of Table in Clause 3.3 - Bed Joints and Perpendsrelating to AS 3700 -2001 Masonry structures.

These diagrams have been prepared in consultation with Standards Australia.

Key diagram showing views

A Horizontal position of any masonry element specified or shown in plan

Eh

G, H, I, J, K

C, Ev, F, L

D

A, B

Base or support

Particular dimension shown on drawing

+_ 5mm Max


B Relative displacement between load bearing walls

C Maximum deviation from plumb within a storey

Vertical section through wall

+_ 10mm Max

Non-structural facework +_ 10mm Max

h = Storey height (metres)

t = Thickness of leaf

= 13mm or +_ 0.05 x 190 = 9mm ie +_ 9mm

For example, if storey height, h = 4.0m and leaf thickness, t = 190mm. Tolerance is the least of


Top of member

Base of member

Structural lesser of +_ OR +_ 0.05 t10h3

3

)(

+_ 10 x 4.0


D Maximum deviation from plumb in total height

E Maximum horizontal or vertical deviation of surface (bow)

+_ 25mm Max

Top of wall

Base

Building may be several storeys high



Must comply when measured horizontally or vertically

2000

+_ 5mm Structural masonry+_ 3mm Non-structural facework


F Deviation step of exposed surface

G Deviation of bed joint from horizontal etc.


Non-structural facework only

2mm Max

+_ 10mm Max

+_ 15mm Max

10 000

Level bed joint

Specified bed joint level

Actual bed joint profile

Actual bed joint profile

Elevation A

G

Elevation A on face


H Tolerance on bed joint width

I Minimum perpend thickness

J Deviation from specified thickness of perpend

Elevation on face

3mm Max 3mm Max

Bed joint

Specified thickness (normally 10mm)

Bed joint

Elevation on face

5mm Min

Perpend joint

Elevation on face

5mm Max

10mm Max

Perpend Joint

Bed Joint

Structural tolerance

Non-structural facework tolerance

Average thickness of perps

Average thickness of perps

5mm Max

Specified thicknessSpecified thickness (normally 10mm)

Specified thickness (normally 10mm)


K Maximum difference in perpend thickness

L Deviation from specified cavity width

Elevation on face

Max Min

Non-structural facework only

(max-min) ≤ 8mm

Section through cavity wall

Specified cavity width

Specified cavity width

15mm Max

15mm Max


Home BuildingServiceThe Home Building Service (HBS) waslaunched in February 2003. It is the resultof structural changes within the Office ofFair Trading, which brings together allbuilding-related functions, for examplelicensing, compliance and operation of theprivate home warranty insurance scheme.It also establishes some new functions suchas dispute resolution, building inspectors,training and education. Regionaloperations of HBS will operate out of thestate-wide network of Fair Trading Centres.

The Service

• Has responsibility for the licensing ofbuilders and tradespeople in the homebuilding industry and a number ofspecialist trade categories across allindustries.

• Maintains a public register of licenceholders.

• Provides a disputes resolution system for both consumers and industry (from 1 July 2003).

• Conducts compliance and/or technicalinvestigations into licensed andunlicensed home builders andtradespeople. It also conductsinvestigations into home building market practices.

• Facilitates prosecutions, civil litigationand other disciplinary enforcementaction.

• Administers Government fundedconsumer protection insurance schemes.

These schemes closed for new policies inMay 1997 and will be wound up in May2004. Private insurance companies nowprovide this insurance to protectconsumers against insolvency orincomplete work by licensed buildersand contractors.

• Administers the Government fundedBuilding Insurer’s GuaranteeCorporation (BIG Corp) which wasestablished as part of the NSWGovernment rescue package to assistvictims of the HIH collapse.

• Monitors the present Home WarrantyInsurance Scheme.

• Oversees the implementation of buildingreforms, co-ordinates ongoing reviews ofhome building laws and theimplementation of proposed reforms.

• Assists industry to improve its standardsthrough Training and requirements,programs and initiatives.

Key home building legislation

The Home Building Act 1989 prescribes theconditions for licensing, contracts, disputeresolution and disciplinary process.

Home building publications

We have publications on a range of usefulhome building topics, such as:

• post-construction home maintenance

• resolving a building dispute

• home warranty insurance

• home building contracts

and many more.

Where to get more information

For more information on the HomeBuilding Service or a copy of anybuilding publication, call:

1300 554 668

or go to

www.fairtrading.nsw.gov.au/building

phone13 32 20

Fair TradingCentre locations

AlburyArmidaleBathurstBlacktownBroken HillCoffs HarbourDubboGosfordGraftonHurstvilleLismoreLiverpoolNewcastleOrangeParramattaPenrithPort MacquarieQueanbeyanSydneyTamworthTweed HeadsWagga WaggaWollongong

July 2003 FT242

Fair Trading Centres – call 13 32 20 for general enquiries

For help on any fair trading issue call your nearest Fair Trading Centre, or call thespecialist service listed below which is relevant to your inquiry. A range of FairTrading services are also available via Government Access Centres (GACs) andother agency locations throughout regional New South Wales. For details, visit the Web site www.fairtrading.nsw.gov.au

Language assistance

Ring the telephone interpreting service on 13 14 50 and ask for an interpreter in yourlanguage.The interpreter can then contact the Office of Fair Trading.

TTY..................................................9338 4943* Telephone service for the hearing impaired.

Office of Fair Trading1 Fitzwilliam Street Parramatta NSW 2150 PO Box 972 Parramatta NSW 2124Tel. (02) 9895 0111

www.fairtrading.nsw.gov.au

Visit the Home Building Service Web site

www.fairtrading.nsw.gov.au/buildingwhere you can:• search the public register on-line to see if a contractor’s licence

is valid and current before entering into a contract, and• find helpful information for homeowners, builders and tradespeople on home

building matters.

Specialist Services

Tenancy Inquiries ............................9377 9100....................1800 451 301(outside Sydney)........................................................9377 9099 (*TTY)Strata Schemes..................................9338 7900....................1800 451 431(outside Sydney)Aboriginal ........................................9377 9200....................1800 500 330 (outside Sydney)Business Licences ............................9619 8722....................1800 463 976(outside Sydney)Consumer,Trader and Tenancy Tribunal (CTTT) ........................1300 135 399

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