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

Naturally Lyctus SusceptibleS = Susceptible

NS = Non susceptible