Tallowwood. Hardwood Species Specification Data

Timber Species: Tallowwood (Eucalyptus microcorys)

 

TallowwoodNative and common to both Queensland and New South Wales, tallowwood is a tall evergreen, growing to around 40 meters and dependent on moderately fertile soil and high levels of direct sunlight. Tallowwood, despite its dependence on fertile soil and direct sunlight, has been known to thrive in mountainous and hilly and locations where it’s occasionally subjected to both excessive frost and drought.

Named for the greasy, oily feel of the wood when it’s cut, tallowwood has spongy, soft, orange-tinged rough bark and a dense crown of leaves. These leaves, which have traditionally been used to dye woolen and silken cloth, are a natural food source for koalas, and the sap of the tallowwood is highly sought-after by beekeepers for the distinctive flavor it lends to honey.

Tallowwood has naturally high occurring amounts of tannin in its timber, lending it a unique grain structure, beautiful growth rings, and a yellowish-brown hue with olive green notes throughout. It’s a relatively hardy timber with a Janka rating of 8.6 and a density of 990 kg/m³, making it robust and durable yet still workable, and as a result it’s a darling of architectural designers everywhere. Tallowwood is often used for solid timber flooring and decking, as its naturally high tannin count acts as a strong preservative against weathering despite its moderate hardness rating.

 

Physical Properties

Dry Density:  990 kg/m³

Janka Hardness: 8.6 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 Tallowwood

Species Name

Tallowwood

Botanical Name

Botanical Name

Eucalyptus microcorys

 

 

Colour Range

Brown

Janka Hardness

Janka (Hardness) Rating - Dry

8.6

Natural Durability
Natural Durability Class

In-ground contact
Outside above ground contact

-

1

1

Timber Density
Density (kg/m3)

Unseasoned (Green)
Seasoned (Dry)

-
1230
990

Strength Group

Strength Group

Unseasoned (Green)
Seasoned (Dry)

-
S2
SD2

Joint Group
Joint Group

Unseasoned (Green)
Seasoned (Dry)

-
J1
JD1

Fire Indices
Fire Indices

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

-
5

4

>2.2 to <4.5
<750
3
Unknown

Tangential Shrikage
Tangential Shrinkage %

6.1

Timber Toughness

Toughness (Nm)

Naturally Unseasoned(Green)
Seasoned (Dried)

-

20

 17

Termite Resistant

Naturally Termite Resistant to AS3660

R = Resistant
NR = Non resistant

RESISTANT

Lyctu Susceptible

Naturally Lyctus Susceptible

S = Susceptible
NS = Non susceptible

 SUSCEPTIBLE

 Australian Hardwood Timber Species | Tasmanian Oak