Jarrah Timber Guide
Everything you need to know about jarrah timber.
Jarrah Timber Technical Information
Jarrah (Eucalyptus marinata)
Jarrah is one of the few commercial species from Western Australia. Jarrah is renowned world-wide for its density, resistance to insect attack and beautiful rich red colour which deepens over time into a soft burgundy. Jarrah’s beautiful colouring and exceptional hardness and natural properties include a high resistance to weather, rot, termites and even marine borers, making it valuable for a range of outdoors uses. Its density also makes it fire resistant. It can be used in wharf and bridge construction, railway sleepers, cross arms, poles and piles. Construction applications include general house framing, flooring, linings, joinery and fencing.
Physical Properties
- Dry Density: 820 kg/m³
- Janka Dry Hardness: 8.5 kN
The Janka rating is the hardness level given to each species. The higher the number, the greater the hardness.
| Species Name | Jarrah | |
| Botanical Name | Eucalyptus marginata | |
| Colour Range | Red | |
| Janka (Hardness) Rating – Dry | 8.5 | |
| Natural Durability Class | In-ground contact | 2 |
| Outside above ground contact | 2 | |
| Density (kg/m3) | Unseasoned (Green) | 1170 |
| Seasoned (Dry) | 820 | |
| Strength Group | Unseasoned (Green) | S4 |
| Seasoned (Dry) | SD4 | |
| Joint Group | Unseasoned (Green) | J2 |
| Seasoned (Dry) | JD2 | |
| Fire Indices | Spread-of-Flame Index | 3 |
| Smoke-Developed Index | 3 | |
| Critical Radiant Flux | >2.2 and <4.5 | |
| Smoke Development Rate | <750 | |
| Group Number | 3 | |
| Naturally bushfire-resisting Timber | Unknown | |
| Tangential Shrinkage % | 7.4 | |
| Toughness (Nm) | Naturally Unseasoned (Green) | 13 |
| Seasoned (Dried) | 10 | |
| Naturally Termite Resistant to AS3660R = Resistant
NR = Non resistant |
R | |
| Naturally Lyctus SusceptibleS = Susceptible
NS = Non susceptible |
S |