Healthy choice

Timber floors do not collect or conceal dust and dirt, making them a perfect flooring surface for those suffering from asthma and allergies.

Safe flooring

When considering timber floors in public area you must ensure that timber flooring finish meets slip resistant requirements. According to AS 4586 public areas like staircases, ramps in food courts, cafes, foyers or any area where spillage might occur, timber floors require to have slip resistant finish rated R10. Please contact JU Flooring for best finish solution.

Ambient condition effects to timber

Timber exposed to air, will change its moisture content in according to changes in the atmosphere, and will shrink or swell accordingly. As the temperature increases or decreases, so does its ability to hold water. The following table represents relationship between moisture content inside the timber at various relative humidity and ambient temperatures, when dried timber has been exposed for prolonged time. As we can see that higher ambient temperature and relative humidity leads to the higher moisture content inside the timber.

Ambient Temperature Moisture content at various relative humidities (%)
C 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95
0 1.4 2.6 3.7 4.6 5.5 6.3 7.1 7.9 8.7 9.5 10.4 11.3 12.4 13.5 14.9 16.5 18.5 21.0 24.3
10 1.4 2.6 3.6 4.6 5.5 6.3 7.1 7.9 8.7 9.5 10.3 11.2 12.3 13.4 14.8 16.4 18.4 20.9 24.3
20 1.3 2.5 3.6 4.5 5.4 6.2 7.0 7.7 8.5 9.3 10.1 11.0 12.0 13.1 14.5 16.0 18.0 20.5 23.9
30 1.2 2.4 3.4 4.3 5.2 6.0 6.7 7.5 8.2 9.0 9.8 10.6 11.6 12.7 14.0 15.5 17.5 20.0 23.4
40 1.1 2.2 3.2 4.1 5.0 5.7 6.4 7.1 7.9 8.6 9.4 10.2 11.1 12.2 13.4 15.0 16.8 19.3 22.7

Forest products Laboratory of U.S. Department of Agriculture developed dimensional change coefficient to reflect how much timber will shrink or swell based on different ambient conditions.

Example: A red oak( change coefficient is 0.00369) board 100mm wide experience a moisture content change from 6 to 9% – a change of 3%. Hence change in the width is 3×0.00369×100 = 1.107mm for one board and across say 6m room this makes 66mm.In actual practice expansion would be diminished in a complete floor, as the timber board’s proximity to each other tends to restrain movement. Nevertheless, we can see how important to plan for expansion joints and also control interior environment (relative humidity and temperature).

Our recommendation for relative humidity is 30-50% and for ambient temperature 16-27 Celsius, where timber floors are present all year around.

Timber discoloration caused by natural light

In the images we can see the profound effect natural light can have on timber color over the time.
The right side in the photo has been covered, while the left side has been exposed to sunlight for two weeks.
As we can see that exposed timber has darkened significantly.

This darkening of fibers at the timber surface is called oxidization and happens when organic compounds go through chemical change in response to light.

This change only involves the surface fibers, and original color will be restored with re-sanding.
Some timber species can become lighter, rather than darker.

Timber floor finishes

Waterborne finishes are a blend of synthetic resins, plasticizers and other film-forming ingredients that produce a durable, moisture-resistant surface. There are one and two-component waterborne finishes. While single-component finishes are ready to use right out of container, two-component waterborne finishes need to have a catalyst, or a “cross linker”, mixed into them on the job site. These finishes are generally applied over a sealer (either solvent or water based) that not only enhances the color of the timber but can significantly reduce the risk of edge bonding. Quick drying time, low odour during application, and very good wear resistance makes it the number one finish in the domestic house today. These finishes are available in different gloss levels and generally darken a little with time.

Oil modified finishes are a petroleum base with a blend of synthetic resins, plasticizers and other film-forming ingredients that produce a durable, moisture-resistant surface coating. Oil modified urethanes are the predominant floor finishes used in the USA and many of the ‘Tung oil’ base finishes are of this type. The odor during application is strong but dissipates as the finish dries. These finishes are available in different sheen levels and tend to darken with time and are unlikely to edge bond boards.

Solvent based moisture-cure finishes cure by absorbing minute quantities of moisture from the air, which causes the finish to dry and harden. These finishes provide a harder finish and much greater abrasion resistance, but with limited flexibility. Consequently, this greatly reduces the level of routine maintenance. Currently solvent base finish is one of the hardest finish in the market for timber floors. They are available in different sheen levels, will generally darken over the time, and edge bonding of boards can occur.

Traditional Tung-oil finishes are a blend of Tung oil and synthetic resins. During application, it is slightly absorbed into the surface of the wood and allows natural seasonal shrinkage and expansion without highlighting the gaps between boards.

Natural oil finishes are a solvent-free, faintly smelling oil with excellent properties. Natural oil is oxygen curing and provides a beautiful smooth non-yellowing surface with an excellent resistance to wear and tear. Natural oil finishes are unlikely to edge bond boards

In this table you can find a summary of the different timber finishes JU Flooring can provide for your new or existing timber floors. The cost column is an indicative cost only, based on a system of one coat each of stain and sealer and two coats of finish. Natural oil is based only on two coats of polished oil. If your job does not require staining then the cost per m2 shall be slightly less.

Finish type Number of coats required Drying time Color Sheen Odor Cost $/m2
Water base urethane 2-4 Fast Clear Matt to Gloss Mild 9
Oil-modified urethane 2-3 Slow Amber Satin to Gloss Moderate 6
Solvent base moisture cure polyurethane 2-3 Slow to Fast Clear to Dark Satin to Gloss Strong 6
Tung oil 2-3 Slow Amber Satin, gloss Moderate 6
Natural oil 1-2 Fast Clear Matt Mild 3


How strong are your wood floors?

Each wood species have its own hardness level and Janka Hardness Test is design to measure just that. During the Janka hardness test a steel ball, 11.28 mm in diameter, is embedded into the wood to a depth of about 5.64 mm. The force required to do this is measured. Therefore if you want to compare relative hardness of wood species we highly recommend checking the Jankas Hardness Test table. It is good indication of how your timber floor will perform with foot traffic scratches or indentations from heavy items such as a piano or heavy furniture with small bearing legs. In order to give a better understanding to the Jankas Rating, we have provided the force in kilograms rather than the usual kilo newtons.

Flooring Species Jankas Rating,kg
Amber Ash 880
American Oak 600
Australian Beech 750
Bamboo (horizontal) 587
Bamboo (strand woven) 1610
Bamboo (vertical) 658
Blackbutt 880
Blue Gum 1400
Brazilian Walnut 1637
Brushbox 950
Cypress Pine 610
Flooded / Rose Gum 750
Forest Reds 910
Grey Box 1500
Grey Gum 1400
Grey ironbark 1630
Ironbark 1400
Jarrah 850
Karri 900
Killarney Ash 720
Merbau 856
Messmate 710
New England Oak 610
Northern Beech 750
Red Ironbark 1190
Red Mahogany 1200
Ribbon Gum 610
Rose Gum (flooded) 750
Satin Ash 600
Spotted Gum 1100
Stringybark 810
Sydney Blue Gum 901
Tallowwood 860
Tasmanian Oak 550
Turpentine 1200
Victorian Ash 449
White mahogany 1000

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