Blackbutt — Eucalyptus pilularis
A workhorse Australian hardwood with Class 1 — Highly Durable above-ground heartwood and strong structural classifications. Strength Group SD2 and Joint Group JD2 seasoned, with a clean golden-yellow appearance that fits modern interiors as easily as it handles exterior decking. Native to the coastal belt from Bega in southern NSW up to Maryborough in Queensland.
Blackbutt products
Decking, cladding, flooring, lining boards, structural framing, joinery and battens — all in the same Class 1 above-ground Australian hardwood, BAL 12.5/19/29 approved.
Technical ReferenceSummary
Blackbutt (Eucalyptus pilularis) is one of Australia's most widely specified commercial hardwoods. Native to the coastal belt from Bega in southern NSW up to Maryborough in Queensland — "readily available" in those areas per WoodSolutions, which translates to short lead times and stable supply for project work.
Its heartwood is classified Class 1 — Highly Durable for above-ground use (more than 40 years per WoodSolutions, AS 5604). Structurally it rates Strength Group SD2 seasoned (S2 unseasoned), Joint Group JD2 seasoned (J2 unseasoned), F-grade F34 seasoned, density 900 kg/m³ air-dry. It is also Lyctus-immune and termite-resistant, which removes two common spec-time risk concerns. BCA Group 4 fire rating and AS 3959 approval for BAL 12.5, 19 and 29 at thicknesses ≥18mm.
Class 1 of 4
Character & Appearance
Heartwood is golden yellow to pale brown, occasionally with a pinkish tone. The sapwood is much paler in appearance and visually distinct. Where Blackbutt differs from most other Class 2 Australian hardwoods is its lighter, cleaner colour palette — it photographs particularly well and suits contemporary interiors and exteriors that lean toward natural rather than chocolate-toned timbers.
Grain is generally straight, though interlocked grain can occur. Texture is even — a key reason it machines cleanly and accepts both clear and stained finishes without surface checking. The species is Lyctus-immune, which eliminates the sapwood treatment requirement common to other eucalypts.
Species & General Properties
Mechanical & Physical Properties
| Property | Unseasoned | Seasoned |
|---|---|---|
| Density | 1,100 kg/m³ | 900 kg/m³ |
| Janka hardness | 6.5 kN | 8.9 kN |
| Modulus of rupture (bending) | 87 MPa | 144 MPa |
| Modulus of elasticity | 15 GPa | 19 GPa |
| Maximum crushing strength | 48 MPa | 77 MPa |
| Strength Group | S2 | SD2 |
| Stress Grade (typical, Structural No.1) | F27 | F34 |
| Joint Group | J2 | JD2 |
| Shrinkage (Total) | Value |
|---|---|
| Tangential shrinkage | 7.30 % |
| Radial shrinkage | 4.30 % |
Recommended Applications
Blackbutt's combination of top-tier strength groups, even straight grain, light golden colour, and natural termite resistance makes it one of the most versatile commercial hardwoods on the Australian market. It performs as well in residential flooring as it does in coastal exterior decking.
Specification Notes
- Natural durability ratings apply to heartwood only. Sapwood, while not Lyctus-susceptible, is not naturally durable for exterior use.
- Recommended spec wording: "Blackbutt (Eucalyptus pilularis) heartwood — AS 5604 Class 1 above-ground durability, Strength Group SD2 seasoned, Joint Group JD2 seasoned, F-grade F34 seasoned typical."
- Lyctus-immune — sapwood does not require Lyctus treatment, unlike many other Australian hardwoods.
- Termite resistant heartwood — additional benefit for exterior applications.
- Bushfire performance: BCA Group 4 fire rating. Approved under AS 3959 for use in BAL 12.5, 19 and 29 bushfire-prone zones at thicknesses of 18mm or greater.
- For UV-exposed applications, oil within 2 weeks of install then 12-monthly maintenance to preserve the natural golden colour.
References
Speccing Blackbutt for a project?Blackbutt for a project?
Coastal NSW and QLD stock means short lead times for most Blackbutt sections. Send us your project specs and we'll quote with lead times — decking, cladding, flooring, structural runs available in commercial quantities.