Tuart is a large hardwood occurring in a narrow strip between the coast and the Darling Range in south-west Western Australia. The best example of the species is probably the stand at Ludlow, near Busselton. Tuart occurs in woodland or open forest, and peppermint (Agonis flexuosa) is a common understorey species. The trees are up to 25 to 40 m tall and 1 to 2 m diameter in the southern occurrence, but only 10 to 15 m in the northern. The trunk is often between one-third and one-half of total height, with the crown well developed with large spreading branches. Tuart grows on shallow siliceous sands or on soils derived from limestone.
Heartwood is pale yellow-brown. The grain is very interlocked and the timber is fine-textured and even.
Green density is the density of wood in the living tree, defined as green mass divided by green volume, and useful for estimating transport costs. It varies with season and growing conditions.
Air-dry density is the average mass divided by volume at 12 per cent moisture content (this is the average environmental condition in the coastal capital cities around Australia).
Basic density is oven-dry mass divided by green volume. This measure has the advantage that moisture content variations in the tree during the year are avoided.:
Green density is about 1250 kg/m3, air-dry density about 1030 kg/m3, and basic density about 840 kg/m3.
Tangential and radial shrinkage before reconditioning are 7.0 and 3.0 per cent respectively, and after reconditioning 5.8 and 2.6 per cent respectively.
With regard to workability, the very interlocked grain makes it difficult to dress smoothly.
The CSIRO Durability Classes are based on the performance in ground of outer heartwood when exposed to fungal and termite attack.
|1||More than 25|
|2||15 to 25|
|3||8 to 15|
|4||Less than 8|
The ratings are not relevant to above-ground use. In late 1996, CSIRO published revised ratings, which include termite susceptibility. Ratings are now available for about seventy species for decay, and for decay plus termites.:
Durability Class based on the CSIRO 1996 ratings is 1 for decay, and 3 for decay + termites. Sapwood is Lyctus-susceptible.
Minimum values (MPa) for strength groups for green and seasoned timber come from Australian Standard AS2878-1986 'Timber - Classification of strength groups'. In grading structural timber, each species is allocated a ranking for green timber of S1 (strongest) to S7, and for seasoned timber SD1 (strongest) to SD8.
MOR is modulus of rupture or bending strength, MOE is modulus of elasticity or 'stiffness', and MCS is maximum crushing strength or compression strength. Hardness refers to the Janka hardness test and is a measure of resistance to indentation.
Minimum values (Mpa) for green timber
Minimum values (Mpa) for green timber
Where test data were available, they are shown in bold print. Most values are from Bootle (1983), Wood in Australia. Types, properties and uses. (McGraw-Hill), or Julius (1906), 'Western Australian timber tests 1906: The physical characteristics of the woods of Western Australia'.
Where no strength data were available, air-dry density was used in accordance with the Australian Standard AS2878-1986 Timber - Classification of strength groups to predict the strength group. Consequently, the strength values quoted are from the above two tables.:
Green and dry strength groups are S3 and SD3. The more important strength properties are given in the table below.
|Modulus of Rupture||MPa||81||125|
|Modulus of Elasticity||MPa||12000||16000|
|Max Crushing Strength||MPa||46||72|
Timber is generally not commercially available from state forest, although occasional logs may be supplied from private property.
Uses have been for general building purposes and flooring. Tuart was once used for keels, stern posts, bridge supports, shafts and wheelwright work where great strength, solidity and durability were required, as well as railway carriage construction.