Properties of Popular Timber Species

The Properties listed for each specie are specifically related to products intended for Ceilings, Internal Panelling, External Cladding, Internal & External Screening, Window & Door Joinery.

As all of these applications are primarily non-structural, properties relating to structural performance of the specific timber species (strength group, stress grade, joint groups etc) are not included.

Similarly, as these products are supplied from seasoned, pre-machined stock, properties relating to machining suitability, grain, shrinkage are also excluded.

Notes and descriptions as referred to in the Specie Properties Tables

01. Common Name / s

The common name by which the specie is generally known. This may include more than one reference and may vary between states.

02. Botanical Name

The Botanical Name is the only reference which ensures precise matching of the specie intended with the specie supplied. While it may not be critical in a lot of cases, one specific instance where it is in the specification of proven bush-fire approved species. 

03. Primary Origin

Intended to clarify if a specie is native to Australia or imported from specific regions. For native species, also provides a guide as to the Australian States generating the bulk of the commercial supply.

04. Colour & Figure

A general indication of colour & figure characteristics is provided but accurately describing the full gambit of variables is impossible. To gain a better understanding of the range, we recommend an “image” search of the particular specie through Google.

05. Density

The commercially recognised density of individual species is shown.
Density primarily relates to hardness but it is often incorrectly related to durability – see also 6, 7 & 8 below.
If a high density specie is mistakenly selected for durability, it may not be any more durable than a suitable low density specie BUT will impose a significant weight disadvantage – this is particularly significant with all external screening and some cladding applications

06. Hardness

The JANKA rating is a universal standard which rates the hardness of timbers on a scale from a low of about 1 (balsa is 0.5) to around 20 (Lignum Vitae, one of the world's hardest is 20)

The ratings fall into four broad categories :
  0.5 to   5.5  -  Soft
  5.5 to   7.0  -  Moderate
  7.0 to 10.0  -  Hard
  10.0 to 20   -  Very Hard

Relative Hardness is a broader industry scale encompassing five levels of hardness :-
              Very Soft,  Soft,  Firm,  Hard and  Very Hard.
While this property provides attributes for a surface requiring a hard wearing performance, it is irrelevant for many applications like ceiling linings, most claddings, most external screening.

07. Durability

For external applications (weather exposed), inherent properties (largely unrelated to density) of a particular timber specie are what classify it as suitably durable (weather exposed – above ground). (All timbers are suitably durable for internal applications - weather protected).
See 8 below for suitability relating to external cladding & screening – weather exposed

08. Weather Exposed

The Tables simply state that the particular specie is ‘Suitable’ OR ‘Not Suitable”

09. Grade Options

Generally unique to each specie and appropriate references are made.                          

10. Leaching

Comments are included to provide a guide as to the likely staining of adjoining surfaces as a result of water running over un-coated product

11. Thickness
  (finished dressed)

For mainline proprietary products like cladding and panelling, the finished thickness is generally in line with industry standards and these details are fully covered on the Timbeck web site –  www.timbeck.com.au
The thickness dimensions quoted on the individual specie sheets represent the range of standard sizes for square dressed and screening sizes.
Thicknesses greater than 50mm nominal are generally not available seasoned. If unseasoned material is not suitable for applications requiring greater than 50mm thickness, consideration might be given to a laminated product.

12. Width
  (finished dressed)

For mainline proprietary products like cladding and panelling, the finished width is generally in line with industry standards and these details are fully covered on the Timbeck web site –  www.timbeck.com.au

The width dimensions quoted for individual species represent the range of standard sizes for square dressed and screening sizes.

13. Length

The range of lengths shown for individual species reflects the normal commercial length availability for all products of that specie – screening & cladding etc. For a lot of hardwood species, quantities of set lengths are not readily available. The maximum length of some species may be significantly different to what can be supplied in others.

Length factors may have a significant influence over specie choice in some instances.
 

14. Price Guide

It is difficult to provide an overall guide on comparative prices of a particular project from each different species. Shorter length specifications may favour some species while size of end section may make others more economical. The figures referenced in each ‘Price Guide” are intended to reflect a broad average across all criteria and provide a starting point to understanding the likely difference in costs between the species.

The BASE PRICE of 100 against which each specie is compared relates to a supply in Western Red Cedar of a similar physical specification.

Final accurate comparisons can not be made until a comprehensive project specification is available.

15. Coating
  (external)

Addresses aspects of the supply of un-coated and pre-coated timber and preferred finishing materials for weather exposed external applications.

16. Coating
  (internal)

Addresses aspects of the supply of un-coated and pre-coated timber and preferred finishing materials for weather protected and internal applications.

17. Availability

Draws attention to possible lengthy lead times, particularly for some imported species where the overall stockholding in Australia is limited. 
Rates species which are subject only to normal re-manufacturing lead times.

   
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