Floor Performance

Even board surface

There are some conditions that affect the surface of the boards and these should not generally occur in timber

fl oors. However, fl oors exposed to heat sources after occupancy (e.g. no curtains, fi replaces, vents from

appliances, houses closed up for extended periods) may cause movement in the fl ooring resulting in effects

such as gapping. Similarly, changes that affect the conditions beneath a fl oor can also result in board movement

and shape changes resulting in cupping. It should be noted that the actions or inaction of owners and builders

can contribute or even cause these effects to occur. Therefore it is benefi cial for fl ooring contractors to make

builders and owners aware of aspects that could affect their fl oor and that any concerns that the builder or owner

has, be brought to the attention of the fl ooring contractor at an early stage. Product choice, particularly in terms

of board width will also infl uence movement after installation, with wider or thin boards often being more prone

to some cupping and gapping in a dry internal environment. The conditions defi ned below should however not

normally occur in a fl oor and if they do, remedial work is often necessary.


Cupping – boards with their edges higher than the centre of the

board. Moist conditions beneath a fl oor can cause cupping and

heat in a specifi c location or a very dry environment above the

fl oor can also cause boards to cup. Cupping is more likely to

be observed in overlay fl ooring and in wide standard thickness

boards. To some degree a small amount of observable cupping

may occur in some locations where these types of fl ooring are

used (e.g. sun exposed fl oor).

Peaking – This has the appearance of cupping but is the result of

expansion pressure in the fl oor. Again it is generally expected that

a fl oor would be free of observable peaking.

Tenting – This is not acceptable and occurs when the adjoining

edge of two boards has lifted above the level of the adjacent

fl ooring. This is often associated with high moisture beneath the

fl oor and can be from a number of other causes.

Buckling – This is not acceptable in a fl oor and occurs when a section of fl ooring containing a number of boards

has risen above an adjacent section of fl oor.

Crowning – boards with their edges lower than the centre of the board. This is not acceptable and occurs when

a cupped fl oor from moisture effects has been prematurely sanded. Crowning may not become apparent until

some months after fi nishing.

Gapping at board edges

Gaps at board edges do not necessarily constitute a problem with a fl oor and simply refl ect seasonal changes

in weather conditions. Shrinkage gaps between boards may average 0.75 mm for an 80 mm wide board fl oor

during drier times of the year or dry internal conditions. For wider boards, proportionally wider average gapping

can be expected. Therefore owners of wider board fl oors need to be more accepting of gaps as this simply

refl ects the natural response of timber. Some gaps will be larger than the average and others smaller, however

the appearance should generally indicate gapping between most boards. An appearance can be expected that

is free from irregularly spaced wide gaps across the fl oor associated with edge-bonding (the fi nish gluing groups

of boards together). The provision of expansion gaps as part of the installation process and evident throughout

the life of the fl oor is acceptable.

Vertical movement at T & G joints

Flooring is manufactured with the board tongue narrower than the groove. This is necessary so that boards

will fi t together during installation. When fl oor boards are laid over joists or battens, some differential vertical

movement may occur between adjacent boards when there is foot pressure on an individual board. This is due to

the clearance between the tongue and the groove. The clearance should not exceed 0.6 mm to comply with AS

2796 Timber – Hardwood – Sawn and milled products, but with this tolerance movement will be observable.


A small amount of noise can be expected from most timber fl oors when walked on. Noises can occur from

movement of one board edge against another or from boards moving on nails. A fl oor is often more noisy during

drier weather due to loosening at the joints. A fl oor that squeaks excessively requires remedial action.


Timber strip fl oors can be expected to show some indentations depending on the hardness of the species used,

variation in density, volume of traffi c and type of foot ware worn. Softer timber will indent more readily than harder


Drummy Spots

When timber fl oors are laid direct to concrete slabs, drummy sounds can occur under some boards. When there

are a limited number of instances associated with one or two boards in some areas of the fl oor, and no vertical

movement when pressure is applied, remedial work is unlikely to be required. Refer to ATFA Information Sheet

No. 6 Hollow Sounds.

Acceptable Floor Appearance

Timber Colour, Grade and Species

Within a single species the colours and colour variation can

be quite pronounced and can differ markedly from one fl oor

to another. It is also possible that a limited number of boards

of different species but similar in colour and character will

be present in some fl oors and this should not be cause for

concern. Through grading errors or when a fl oor is sanded, it

is also likely that some features will appear or be a little larger

than the grade description. There is however generally a clear

difference between a fl oor that is of the incorrect grade and a

fl oor where grade limits have been exceeded in some boards.

Such fl oors where the grade description is exceeded in some

boards should also not be a reason for concern. Refer to ATFA

Information Sheet No. 5 Floor Colour and Grade.

Board lengths and distribution in the fl oor

Board lengths are generally a minimum of 900 mm long when laid on joists or battens. When laying over a

structural sub-fl oor the minimum length may be shorter. Where possible end joints should not cluster together or

align. Generally, only one end join should occur in a group of three boards between fl oor joists. In the case of glue

fi xed fl ooring, it is preferred that end joints be a minimum of 300mm from end joints in adjacent boards.


The sanding process involves hand controlled equipment and due to this there will be some evidence of the

sanding process in the fl oor. It can be expected that the fl oor will be fi ne sanded and that edging will not result in

scalloping. Similarly it can be expected that corners will be scraped to an even surface and sanded to provide a

fi ne surface. As such sanding marks in the timber should not be visible from a standing position. Generally, the

viewing angle for assessment should be 45° from the eye to the fl oor.

At times there can be vibration that occurs which may be induced by the sanding machine or the sub-fl oor

framing. Although this vibration can lead to chatter marks in the fl oor, it would be usual to expect a fl oor free of

chatter marks.

With the re-sanding of an older fl oor it must also be recognised that the sanding process will not remove existing

deep cuts or damage and that stains may also not be removed if they have penetrated deep into the timber.

Nail Holes and Filling

Unless otherwise requested, all fl ooring nails are to be punched below the surface and the nail holes are to be

fi lled. With solid T&G fl ooring it can also be expected that any gaps at board ends will also be fi lled. Filling at board

edges is generally not recommended except for parquetry where fl ood fi lling is to be undertaken and in some

instances with direct adhesive fi xed fl oors. When one colour of fi ller is used, that colour should match the darker

tone in the boards as with time the contrast generally becomes less.

Coating and Finishing

A fl oor is subject to much heavier wear than furniture and although a good quality fi nish can be expected, the

same fi nish quality to furniture should not be expected. There are a number of imperfections that are likely to

be present to some degree in a fi nished fl oor and the degree to which they occur, where they occur and the

presence of other imperfections, will determine their acceptability. When assessing the appearance of a fl oor

it is to be done from a standing position and the fl oor should be viewed at an angle of about 45°. Common

imperfections present to some degree in fl oors are outlined below.

Dust and debris – A degree of contamination in the fi nal coat is unavoidable and will vary from one site to another

being dependent on a number of factors such as draughts, heating and ventilation systems, insects and the like. It

can be expected that the contractor will take reasonable measures to minimise the risk of contamination and that at

job completion there will not be heavily contaminated areas in the fl oor that are obvious when assessing the fl oor.

Swirl marks – Swirl marks are caused by rotary sanders and to some degree will be present in all fl oors. Down

lights will highlight sanding imperfections due to light refraction through the coating and as such this is not

controllable by the contractor. Fine swirl marks that are not obvious under natural light when assessing a fl oor

should not be a concern.

Coat levelling – Rejection, orange peel and quilting all relate to unevenness in the coating resulting in either a

mottled effect or in the case of quilting discontinuity across joints. If instances are isolated, minimal in nature and

not in areas frequently viewed then remedial work is unlikely to be necessary.

Delamination – Separation of one coating from another or from the coating to the board should not generally

occur in a fl oor and in such instances remedial work is necessary. Minor delamination due to movement at board

joints or ends can occur and provided it does not progress, remedial work is unlikely to be necessary.

Gloss variation – Differing conditions in the dwelling at the time of curing can result in gloss variation. Although

consistency can be expected at the time of a particular application, some variation may be apparent between

areas when fi nished at a different time. Gloss variation within a room particularly with satin fi nishes usually

requires remedial work.

White lining – When gaps appear at board edges the stretching of the bridged coating can cause a white line to

appear at board joints. Unless severe this conditions requires no remedial work.

Lap and roller marks – Some fi nish systems are more prone than others and should lap or roller marks occur,

they need to be minimal in number and not able to be observed from all directions, to be acceptable.

Edge bonding – Some fi nish systems can act as an adhesive and bond board edges together. With shrinkage

in the fl oor, wide irregular spaced gapping and splits in boards can occur. Only minor edge-bonding resulting in

small gaps at board edges is acceptable. Frequent splits and wide gaps are not acceptable.

Ghosting – Lighter toned boot and foot prints can occur in fl oors 6 to 18 months after the fl oor has been fi nished.

In most instances the source of the mark cannot be identifi ed and in most instances not likely to be associated

with the sander and fi nisher. Re-sanding and fi nishing may correct the problem and a compromise between

parties is often necessary to resolve the problem.

Colour Changes to Timber and Coating

Over the course of time colour changes occur in timber fl oors from the

effects of ultra violet light. Therefore it is usually more pronounced in sun

exposed areas of the fl oor. This is partly associated with the changes

in the timber and partly with the coating that is applied. Some coatings

darken with time more than others and some timbers are more prone

to colour changes than others. This process is natural and gradual but

can result in distinct colour differences where rugs have been put on

the fl oor. Some of this change can be minimised by not putting rugs

down till six or so months after the fl oor has been completed. To avoid

severe effects it is benefi cial for fl ooring contractors to make clients

aware of how the coating used may result in colour differences. From

there it is up to the owner to manage how rugs are used.


This information sheet outlines reasonable owner expectations

for an onsite sanded and fi nished timber fl oor. This includes solid

T&G fl ooring, parquetry and other fl ooring types that have been

sanded and fi nished onsite or recoated. Concerning this, there are

performance aspects of the fl oor which generally relate to fi xing

integrity, board shape and movement, and then there are appearance

aspects which focus more on the sanding and fi nishing.

Although an imperfection free fl oor is the desire of any tradesperson,

it is the process of installation and fi nishing where the environment

and other conditions cannot be fully controlled that moves the

completed job to one that is ‘normal’ and of an industry accepted

standard. This however is not to say that the completed fl oor

won’t be of a high standard and well suited to its purpose as a

fl oor which is to be walked on, but it does acknowledge that the

fi nished product will not be the same as fi ne furniture and that

due to seasonal infl uences and heating and cooling, that some

movement refl ecting the nature of timber will occur.

Concerning the installation of the fl oor, the provisions are outlined in either the ATFA publication ‘Timber Flooring’

(2009) or specifi c manufacturer recommendations for their products. The sanding and fi nishing of timber fl oors

is covered by AS 4786 – Timber Flooring – Sanding and Finishing along with a general description of the process

provided in ‘Timber Flooring’.


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