Properties and Uses

Giam

The Standard Malaysian Name for the heavy timbers of Hopea spp. (Dipterocarpaceae). The timber is a heavy hardwood with a density of 865–1220 kg m^–3air dry. The sapwood is yellow and is poorly defined from the heartwood, which is yellow with a greenish tinge when fresh and turns deep red-brown on exposure. Texture is very fine to moderately fine and even, with deeply interlocked grain. The timber is extremely strong (Strength group A). It is easy to difficult to resaw and cross-cut. Planing is, however, easy and the planed surface is smooth. Nailing property is rated as very poor. The timber seasons very slowly, with only slight end-checking, splitting and surface-checking as the main sources of degrade. 13 mm boards take approximately 6 months to air dry, while 38 mm boards take 8 months. Shrinkage is average to high, with radial shrinkage ranging 1.4–2% and tangential shrinkage ranging 2.6–4.4%. The timber is very durable and is highly resistant to preservative treatment.

USES: The timber is suitable for all heavy construction, bridges, wharves, posts, beams, joists, heavy duty flooring, power-line poles, railway sleepers, lorry and truck bodies, container floor boards and heavy duty laboratory benches.

Vernacular names applied include giam (P.M.) with various epithets, selangan (Sab. and Sar.) with various epithets and other localised names too numerous to list here. Major species include H. ferrea, H. helferi, H. nutans, H. pentanervia and H. semicuneata.