Jarrah (Eucalyptus marginata)
About Jarrah
Jarrah is uniquely confined to
the temperate forests in the south west corner of Western Australia. Jarrah trees grow to a height of about 30-40 metres (100-130 ft.) and a
trunk diameter of up to 2 metres (6 ft.).
Jarrah decking
Kiln dried to approx. 12%
moisture, jarrah deck timber is available in a range of standard sizes
from 65 x 20mm to 105 x 30mm.
Larger sizes may be available subject to
stock and delivery times. Standard profiles include square edges, pencil
round edges and ribbed surface finish.
Durability:
Jarrah is rated Class 2 durability (on a scale of 4) meaning that the
timber possesses a high natural resistance to decay, termite and borer
attack and can be expected to give long service life under all normal
conditions including ground contact. In exposed in ground conditions, a
typical service life of 15 to 25 years without the use of preservatives
can be expected.
Jarrah is also
highly resistant
to rot, fire, termites, marine borers and most acids
Density:
Jarrah has a density of approx. 835 kg. per cu.m., almost twice that of Redwood
and over double the density of cedar or yellow pine.
Hardness:
Jarrah is rated as "Hard" (rating 2 on a scale of 6 ). It is 4 times
the hardness of Redwood or yellow pine and 5 times the hardness of cedar (Janka
hardness scale). Colour:
The wood of the jarrah tree varies in colour from a rich reddish brown to a soft
salmon pink, depending on the age of the tree. The colour usually darkens with
exterior exposure. Grain
and texture:
Jarrah has a clean smooth surface and dense, straight grain making it much
sought after for fine indoor and outdoor furniture, flooring and mouldings.
Resource management:
A very
large proportion of the Western Australian jarrah forests is
publicly owned and managed on a sustainable yield basis by The
Government Department of Conservation and Land
Management.
The resource management and conservation of the 1.4 million hectares (3.46
million acres) of jarrah forests under Government control is supported by an
extensive research programme which ensures that these beautiful and unique
jarrah forests will always be available for future generations to use and enjoy.
Typical
Decking
timbers - Comparative properties
Property |
Jarrah |
Redwood |
Western
Red Cedar |
Yellow
Pine |
|
Density
(kg/m³) |
835 |
450 |
380 |
450 |
|
Durability |
2 |
1 |
2 |
4 |
|
Hardness
-Janka (kN) |
8.5 |
2.1 |
1.6 |
2.0 |
|
Modulus
of rupture (Mpa) |
112 |
69 |
53 |
57 |
|
Modulus
of elasticity (Gpa) |
13 |
9.2 |
7.7 |
5.2 |
|
Max.
crushing strength (Mpa) |
61 |
42 |
35 |
33 |
|
