Bangkirai

Botanical Name: Shorea spp.
Also known as Yellow Balau, Balau Kuning, Selagan Batu

Native to Malaysia, Indonesia and the Philippines, Bangkirai is a dense hardwood used mainly for heavy construction.

The heartwood of Bangkirai is yellow to brown, which is distinct from the paler sapwood. Its moderately fine and even texture presents and interlocked grain, which produces a stripe figure on the radial surface. Bangkirai is also susceptible to pinhole borer damage.

In relation to its density, Bangkirai is relatively easy to work. It does not contain sillica, however resin pockets may be present, meaning resin can build up on cutting equipment. Pre-drilling is advisable when nailing. Bangkirai can be painted, stained and polished but is not suitable for steam bending.

Density 900kg/m3 seasoned
Strength Groups S3 unseasoned; SD2 seasoned
Stress Grades F8, F11, F14, F17 (unseasoned), F14, F17, F22, F27 (seasoned)
Joint Groups J2 unseasoned; JD2 seasoned
Shrinkage to 12% MC 6.5-8.0% (tangential); 4.0-5.0% (radial)
Durability Above-ground Class 1 – life expectancy over 40+ years
Durability In-ground Class 2 – life expectancy 15-25 years
Lyctine Suceptibility Untreated sapwood susceptible to lyctid borer attack
Termite Resistance Not Resistant
Machining Machines reasonably well to a smooth surface. However, some of the lower density species may give a woolly cut if sharp tools are not used.
Fixing No difficulty has been experienced with the use of standard fittings and fastenings.
Gluing Can be satisfactorily bonded using standard procedures.
Finishing Can be painted, stained or polished. However, due to its open grain timber surfaces may need to be filled before finishing.
Bush Fire Resistance Bal 12.5 and 19 AS3959