May 30, 2015

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Australian Timber Grades

Select Grade
Providing a floor where the feature present or natural discolouration will not dominate the appearance of the floor. Features that are permitted still include short narrow gum veins, a limited number and size of past borer activity and small knots.

Medium Feature – Standard Grade
Providing a floor that may have significantly more character than a Select Grade floor. To some degree this will depend on the features present in a particular species. In one species gum veins may naturally be prevalent while in another there may be few gum veins but past borer activity may be more prevalent. Therefore, this grade can be expected to have greater character than Select Grade, and contain an increased amount of gum vein, past borer activity, knots and natural discolouration.

High Feature Grade – Character Grade
Providing for a floor that contains boards with similar features to Medium Feature – Standard Grade but where the length of features such as gum veins may be longer and past borer activity may be more frequent. Again depending on the species, features will vary and in some instances boards meeting high feature grade may only appear moderately featured.

Standard and Better
This is a mix of Select and Standard grade flooring, however the percentage of each grade in the mix is not set and will vary between one species and another. The intent is however to provide a floor appearance that has a little more character than Select Grade.

Timber Hardness – Janka Rating

The Janka hardness test measures the force required to embed an 11.28 mm steel ball into wood to half the ball\’s diameter. Janka hardness ratings is to determine whether a species is suitable for use as flooring. The harder the timber the less it indents , or scratches. The higher Janka rating corresponds to a harder timber. In Australia the Janka rating is measured in either in newtons (N) or kilonewtons (kN).

Moisture Content

The moisture content of timber is calculated by a percentage weight of water present in the timber compared to the weight of timber with all water removed.

Correct Storage & Handling

The Flooring product should be delivered to site in protective packaging to maintain the products at the appropriate moisture content. The building should be protected form the weather, meaning it should have a roof, walls, sub-floor, windows & doors in an completed operational state.
It is the flooring installers’ responsibility to assess the site conditions are suitable to accept the flooring installation.
This includes checking the timber flooring is at the approximate moisture content at the time of installation.
The flooring product must be protected from weather conditions, from extreme sources of dampness to direct sun exposure, as this will have a detrimental effect.
The flooring product should remain in its original packaging just prior to installation.


The Acclimatisation is the period of time need for the timber to reach its average moisture content for the site where it is to be installed. This will depend on relative changes in the humidity and temperature in the surrounding air. The Timber flooring should be at a moisture content close to the average moisture content of timber in the environment where it is to be laid. The correct period of time is dependant to the relative state of the timber and the site conditions.

Pre installation Conditions

The Timber flooring is normally supplied at an average moisture content (mc)of 8% to 12%.

In a moist in-service environment of an expected average mc from 12% to 15%,
– allow for future expansion and additional expansion allowance
– acclimatisation is required before laying the floor.

In a normal in service environment of an expected average of 10% to 12%,
-no special consideration is required before laying the floor.

In a dry in-service environment of an expected average of 8% to 10%,
– allow for future shrinkage
– acclimatisation is required before laying the floor.


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