Blackbutt (Eucalyptus pilularis)
Blackbutt is a large Australian hardwood that is commonly used for structural and exterior applications.
The name Blackbutt came about due to the tree’s appearance after bushfire, whereby the buttress – or butt – was significantly darkened. It is also known as Coastal Blackbutt to distinguish it from the tableland species, New England Blackbutt.
Due to its quick growth and versatility, Blackbutt makes a good plantation timber. It is a commonly available commercial hardwood species in New South Wales and southern Queensland, often used for building framework.
The heartwood ranges from golden yellow to pale brown, although occasionally a slight pinkish colour may be present. The sapwood, which is not always easy to distinguish, is much paler in appearance and is resistant to attack by lyctid borer. Blackbutt has an even texture and generally straight grain making it appealing for interior use applications.
Blackbutt can be stained, painted or polished but there can be issues with painting because of its tendency to surface check. The high extractives of mature wood can cause problems with some adhesives, but this is much less of an issue with young regrowth wood. These extractives can also cause staining on painted surfaces exposed to the weather. Blackbutt machines well but is only fair for steam bending.
Blackbutt has been found to be suitable (by the Building Commission in Victoria) for home construction in bushfire areas (provided it has a thickness greater than 18mm).
A strong, durable hardwood, Blackbutt can be used for a range of structural, exterior and interior applications including framework, decking, flooring and poles.
|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|
>2.2 and <4.5kWm 2
|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|
Coastal Blackbutt, Pink Blackbutt
Blackbutt has an even texture. The grain can be interlocked but it is generally straight, making it appealing for interior use applications such as flooring and joinery. The heartwood ranges from golden yellow to pale brown, although occasionally a slight pinkish colour may be present. The sapwood, which is not always easy to distinguish, is much paler in appearance. Small gum veins may also be visible.
Blackbutt is a versatile timber and is used for structural, exterior and interior applications. In New South Wales and southern Queensland it is very popular for timber framing but is also used for cladding, internal and external flooring, decking, joinery, landscaping and furniture. Blackbutt is also used in the manufacture of plywood.
Care needs to be taken when drying as Blackbutt is prone to surface checking on the tangential surface. Blackbutt should not be re-conditioned as this will widen any surface checks. Blackbutt can be stained, painted or polished but there can be issues with painting because of its tendency to surface check. The high extractives of mature wood can cause problems with some adhesives, but this is much less of an issue with young regrowth wood. These extractives can also cause staining on painted surfaces after exposure to the weather. Blackbutt machines well but is only fair for steam bending.
Architectural Roof Trusses
Architectural timber roof trusses create strong visual impact. Often used as part of ‘cathedral ceiling’ systems, timber can be specified light or heavy to suit the chosen theme and style. On finish, they can be left natural or may be oiled, stained, painted or highly decorated. Choice is limited only by individual style and design preferences.
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.
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.
Interior Rails and Balustrades
With its natural beauty and inherent strength, timber is a popular material choice in internal balustrade construction. Commonly built from treated softwoods and durable hardwoods, interior balustrades and handrails are typically finished with a clear lacquer to generate the most natural result.
Timber should be the material of choice for designers seeking internal staircases of strength, beauty and durability. The construction procedure described here applies to most general type stairs of either conventional or contemporary construction.
Timber Joinery Products
Timber joinery products offer a classic, unique and stylish touch to any interior design.
Mouldings are extremely versatile and durable, enhancing the aesthetics of any interior and functioning as the icing on the cake for designs with a focus on beauty and splendour.
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.