Tasmanian Oak. Hardwood Species Specification Data

Timber Species: Tasmanian Oak (Eucalyptus delegatensis / Eucalyptus regnans / Eucalyptus obliqua)


Tasmanian Oak

Timber marketed as Tasmanian, or "Tassie Oak” is most often a combination of three distinct species of tree, all of which are found most often in – you guessed it – Tasmania, and while they are all certainly similar there is a wide amount of variation between the three.

Most commonly made from a combination of alpine ash, mountain ash, and messmate, Tasmanian oak is characterized by the commonalities between all three species. All closely related eucalyptus varietals, these trees tend to be straight-trunked, hardy, sub-alpine evergreens that require moderate to high levels of rainfall.

While referred to as “Tasmanian” or "Tassie" oak, all three varietals that are used in the construction of this timber aren’t found exclusively in Tasmania. Many examples can be found in Victoria and New South Wales as well in more mountainous or hilly regions, or anywhere there’s well-drained soil with temperate to cool climate conditions.

Providing straight and uniformly even grain because they’re quarter split, Tasmanian oak mixes are used to produce blends of pleasantly coloured blonde woods that range in shade from reddish-brown, pink, to pale cream.

Easy to work but not known for its durability, Tasmanian oak timbers are on average low on the Janka hardness scale at just 5.5 and relatively light with densities ranging from  650 to 1050 kg/m³ on average, but this will, of course, vary greatly depending on the ratio of the three different types of wood used to create the flooring.

Parquetry and solid timber flooring are the two most common places to see Tassie Oak used, as it allows this unique timber blend to showcase the variations in color and texture. As a soft, light wood, Tasmanian oak isn’t suited to outdoor decking or use in engineered wood.


Physical Properties

Dry Density:  650 kg/m³

Janka Hardness: 5.5 kN

These properties are only a guide, as timber is a natural product there will be variations within any species. The Janka Dry Hardness rating measures the hardness of the wood. The higher the number the harder the wood.

 Technical Properties of Tasmanian Oak

Species Name

Tasmanian Oak

Botanical Name

Botanical Name

Eucalyptus delegatensis / Eucalyptus regnans / Eucalyptus obliqua




Colour Range


Janka Hardness

Janka (Hardness) Rating - Dry


Natural Durability
Natural Durability Class

In-ground contact
Outside above ground contact




Timber Density
Density (kg/m3)

Unseasoned (Green)
Seasoned (Dry)


Strength Group

Strength Group

Unseasoned (Green)
Seasoned (Dry)


Joint Group
Joint Group

Unseasoned (Green)
Seasoned (Dry)


Fire Indices
Fire Indices

Spread-of-Flame Index
Smoke-Developed Index
Critical Radiant Flux
Smoke Development Rate
Group Number
Naturally bushfire-resisting Timber



>2.2 to <4.5

Tangential Shrikage
Tangential Shrinkage %


Timber Toughness

Toughness (Nm)

Naturally Unseasoned(Green)
Seasoned (Dried)




Termite Resistant

Naturally Termite Resistant to AS3660

R = Resistant
NR = Non resistant


Lyctu Susceptible

Naturally Lyctus Susceptible

S = Susceptible
NS = Non susceptible


This page was updated at 4.36pm, 23 February 2018

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