Tallowood (Eucalyptus microcorys)
Tallowood is an extremely hard, durable and versatile Australian native hardwood species. Its timber products are suitable for a wide range of applications.
Tallowwood is a moderate to large tree occurring in wet sclerophyll forests of coastal regions from the Hunter River district of New South Wales to Maryborough and Fraser Island, Queensland.
The heartwood of this species ranges in colour from pale to dark yellow-brown, with occasional tinges of olive green. Sapwood is a whitish colour. The texture of Tallowwood timber is moderately coarse, generally with interlocked grain. Unusually for a eucalypt species, Tallowwood is free of gum veins. Figure is lacking but the timber possesses a distinctive lustre and ‘greasy’ appearance.
Tallowwood timber products exhibit exceptional durability in both in-ground and aboveground applications, where life expectancy is greater than 25 and 40 years, respectively. Although Tallowwood is highly resistant to decay and will withstand damp and wet conditions quite well, its sapwood is susceptible to Lyctid borer (powder post beetle) attack. Untreated timber of this species is equivalent to ‘fire retardant treated timber’ when tested in accordance with AS/NZS 3837.
Historically, Tallowwood has been used for bearings, mallet heads, mauls, wheel spokes, and tool handles. Current engineering applications include wharf and bridge construction (as sawn and round timber), railway sleepers, cross-arms, poles, piles and mining timbers. Construction uses range from unseasoned framing to dressed timber cladding, internal and external flooring, linings and joinery. Tallowwood is also used in fencing, landscaping and the construction of retaining walls. Decorative uses include outdoor furniture, turnery and joinery. Other applications include boat building, the construction of coaches, carriages and agricultural machinery, and structural plywood.
|Very Low||Low||Medium||High||Very High|
|Very High||High||Reasonably High||Medium High||Medium||Reasonably Low||Low||Very Low|
|Structural No 1||Structural No 2||Structural No 3||Structural No 4||Structural No 5|
|Very High||High||Reasonably High||Medium||Low||Very Low|
|White, Yellow,Pale Straw to Light Brown||Pink to pink brown||Light to dark red||Brown, chocolate, mottled or streaky|
Modulus of Rupture – Unseasoned
Modulus of Rupture – Seasoned
Modulus of Elasticity – Unseasoned
Modulus of Elasticity – Seasoned
Maximum Crushing Strength – Unseasoned
Maximum Crushing Strength – Seasoned
Impact – Unseasoned
Impact – Seasoned
Toughness – Unseasoned
|Medium – 15 – 25 Nm|
Toughness – Seasoned
|Medium – 15 – 25 Nm|
Hardness – Unseasoned
Hardness – Seasoned
(> 25 years)
|(0-20 years, usually <5)||(21-40 years)||(41-64 years)||(>65 years)|
|Marine Borer Resistance|
|Lyctid Borer Susceptibility|
EFH Spread of Flame Index
|EFH Smoke Developed Index|
|Critical Radiance Flux – Lower|
>2.2 and <4.5kWm 2
|Critical Radiance Flux – Higher|
|Smoke Development Rating|
|Fire Properties Group Number|
1 – Non Combustible
2 – reasonably non combustible
3 – slightly combustible
4 – combustible
Average Specific Extinction Area
|BAL 12.5, 19 and 29 – All AS3959 required applications|
The heartwood of this species ranges from pale to dark yellow-brown, in contrast to its typically whitish sapwood. The texture of Tallowwood timber is moderately coarse, generally with an interlocked grain relatively free of gum veins. Figure is lacking, but Tallowwood possesses a distinctive lustre and greasy appearance.
Historically, Tallowwood has been used for bearings, mallet heads, mauls, wheel spokes, and tool handles. Current engineering applications include wharf and bridge construction (as sawn and round timber), railway sleepers, cross-arms, poles, piles and mining timbers. Construction uses range from unseasoned framing to dressed timber cladding, internal and external flooring, linings and joinery. Tallowwood is also used in fencing, landscaping, and the construction of retaining walls. Decorative uses include outdoor furniture, turnery and joinery. Other applications include boat building, the construction of coaches, carriages and agricultural machinery, and structural plywood.
Tallowwood is very hard (rated 1 on a 6-class scale) in relation to indentation, yet is relatively easy to work with hand tools due to the timber’s natural greasiness – hence the species’ common name. It machines and turns well, readily accepts paint, stain and polish, and is amenable to the use of standard fittings and fastenings. Pre-drilling is recommended for nailing and screwing. Numerous extractives render Tallowwood difficult to bond satisfactorily, although success has been reported with the use of polyurethane glues.
Timber decking creates spaces that are functional, practical and aesthetically pleasing. With the right design and care a timber deck will make a valuable addition to any home or business, creating an outdoor living space that will be enjoyed for years to come.
The natural appeal, versatility and strength of timber makes it the superior choice for external cladding. Through specification, planning, design and finishing processes, timber cladding not only creates a building of superior strength, acoustic and thermal performance but also creates a place of beauty, style and natural appeal.
When it comes to fencing, timber is your natural choice. A material that is durable, strong and reliable it compliments almost every outdoor landscape and environment. Clear specification, detailed installation and appropriate maintenance will see any timber fence provide a natural and lasting property boundary and back drop for years to come.
Whether for structural or finished flooring applications, timber offers durability, versatility and adaptability. The warmth, strength and natural beauty of timber flooring has proved enduringly popular in a wide variety of interior settings.
Since people began building simple shelters, wooden framing has played an important role in shaping structures of many kinds. One of the most popular types of wooden framing is known as lightweight timber construction.
Timber paneling creates interiors as warm as they are stylish. Commonly utilising an MDF or plywood substrate, internal timber paneling is natural and versatile and comes as either solid natural timber panels or as sheets of engineered wood products
A timber pergola is a practical, functional and attractive way to extend living and entertainment spaces into the outdoors.
Retaining Walls (Landscaping)
When it comes to retaining wall, landscape design and construction, timber is the natural choice. A material that is durable, sturdy and reliable, it boasts natural aesthetics that help it blend seamlessly with the outdoors. Careful consideration during the specification and design process will facilitate the creation of a long lasting, durable and eye catching timber retaining wall that will complement its surrounding landscape for years to come.
Structural Timber Posts
Timber poles are utilised in structural construction to provide support for gravity loads and resistance against lateral forces. Not only serving a structural function, timber poles provide many aesthetic benefits, with their use in construction often complementing architectural designs aimed at harmonisation with the natural environment.
Timber Joinery Products
Timber joinery products offer a classic, unique and stylish touch to any interior design.
Timber Portal Frames
For buildings that require large spans and column free interiors, timber portal frames provide one of the most aesthetically pleasing solutions. Utilising modern engineering technology, portal frame design transforms timber into a highly effective, efficient and economical structural product. This application guide provides a comprehensive overview of the process of using timber in the specification, fabrication and erection of portal frame structures.