Blackbutt
F27 and F17 Structural Hardwood, Bushfire Rated
Blackbutt is one of the most versatile Australian hardwoods, used across decking, flooring, structural framing, and posts. A tough, fast-growing eucalypt from NSW and southern Queensland, it combines real structural strength with a clean, even appearance and, importantly for Sydney builds, a bushfire rating that makes it suitable for BAL-zone construction. We stock it in F27 solid timber from 90×45 up to 290×45, F17, and solid posts in 90×90 and 140×140.
Why Build with Blackbutt
Blackbutt earns its place on strength and durability. The F27 and F17 stress grades handle structural load, while the timber’s natural resistance to lyctid borers makes it reliable for framing and exposed work. It is bushfire-rated: blackbutt is one of the hardwood species accepted for construction in designated bushfire areas (at 18mm thickness and above), which is a genuine advantage on Sydney-fringe and bush blocks.
The heartwood runs golden yellow to pale brown, occasionally with a pink tint, over an even texture and mostly straight grain, so it looks as good as a finished floor or deck as it performs as a post or bearer. A couple of working notes worth knowing: blackbutt can surface check, so it needs care if you are painting, and mature timber carries high extractives that can stain painted surfaces exposed to weather and can affect some adhesives. It machines easily; steam bending results are fair.
What Goes With It
For decks and structural work, fix with galvanised or stainless steel screws and bolts rated for hardwood and exterior use. Comparing species for a deck or floor? See spotted gum and the full hardwood range, or step across to engineered options in the LVL and engineered timber range for beams.
Serving Sydney Tradies and Renovators
- Trade pricing and bulk quantities: Competitive rates on volume orders. Call 1300 554 775 for trade and project pricing.
- Delivered to site across Sydney: Sydney, the Blue Mountains, Wollongong, and the Central Coast.
- F27 and F17 structural grades: Solid timber and posts, bushfire (BAL) rated Australian hardwood.
- Australian-owned family business: Western Sydney based. Real people, real stock, real advice.
Whatever the build calls for, we’ve got the blackbutt.
Call 1300 554 775 or request a quote online and our team will help match grade and section to your job.
Frequently Asked Questions
What is blackbutt timber used for?
Decking, flooring, structural framing, bearers, and posts. Its strength grades and durability make it suit both structural and finished applications.
Is blackbutt bushfire rated?
Yes. Blackbutt is one of the hardwood species accepted for construction in designated bushfire (BAL) areas, provided it is at least 18mm thick. Confirm the rating for your specific application.
Is blackbutt good for decking?
Yes. It is hard, durable, and bushfire-rated, with an even colour that finishes well, which makes it a popular Australian decking hardwood.
Can blackbutt be painted or stained?
It stains and polishes well, but can surface check, so painting needs care. Mature timber’s high extractives can also stain painted surfaces exposed to weather, so seal appropriately.
What strength grade is blackbutt?
BBS stocks blackbutt in F27 and F17 structural grades. F27 is the higher grade for heavier structural loads; your engineer or the span requirement determines which you need.