Introduction |
The Standard Malaysian Name for the tree and timber of
Cotylelobium spp. and Vatica spp. (Dipterocarpaceae). Vernacular names
applied include resak (Peninsular Malaysia, Sabah and Sarawak) with
various epithets, balau (Peninsular Malaysia) in error, damar keluang
(Pahang), jenuong (Johor) and keruing babi (Peninsular Malaysia). Major
species include Cotylelobium lanceolatum, C. melanoxylon; Vatica bella,
V. cuspidata, V. flavida, V. havilandii, V. heteroptera, V. lowii, V.
maingayi, V. mangachapoi, V. nitens and V. scortechinii. The sapwood is
lighter in colour than the heartwood and is sharply defined in
Cotylelobium but not generally so in Vatica. The heartwood is pale
yellow when fresh and turns to deep red-brown on exposure in
Cotylelobium and a fine brown with a green tinge in Vatica. Also known
as Resak (Brunei); Chrama:hs (Cambodia); Vatica (India); Giam, Resak and
Resak bukit (Indonesia); Chik dong, Mai ka cha, Mai si and Mai si khao
(Laos); Vatica (Papua New Guinea); Narig (Philippines); and Chan Thip,
Dam Darng, Khian, Khiem, Kiam, Pan-Cham, See, Tamsao and Yang-nu
(Thailand). |
Botanical Name |
- |
Natural Durability |
Graveyard tests on V. cuspidata, a species with an
average air dry density of 1,040 kg/m3 indicated that the timber has an
average service life of 14 years under natural conditions. The timber is
therefore, classified as very durable under Malaysian conditions
(Jackson, 1965). Desch (1941) recorded that tests carried out to
determine the quality of resak timber indicated that some forms of resak
were found to be exceptionally durable (presumably the heavier
varieties), ranking with the best forms of balau and giam, and the
inferior forms (presumably the lighter varieties) would appear to be at
least moderately durable. Burkill (1935) stated that the timber of
Cotylelobium is of excellent quality and resistant to Teredo, a type of
marine borer. Burgess (1966) however, reported that the timber of Vatica
species is not resistant to marine borers and failed within 12 months
in Papua New Guinea. In general, resak should not be accepted as
resistant to marine borers, but material of Cotylelobium, since it
contains silica, is likely to be more resistant than Vatica. |
Uses |
The timber is suitable for all forms of heavy
construction, bridges, piling, marine construction, beams, posts,
joists, pallets (permanent heavy duty), door and window frames and
sills, tool handles (impact), flooring (heavy traffic), power
transmission poles, laboratory benches, vehicle bodies (framework and
floor boards), railway sleepers, fender supports, staircase (angle
blocks, rough brackets, carriage, riser, stringer, tread, bullnose,
round end and winder), cooling tower (structural members), telegraphic
and power transmission posts and cross arms, heavy duty furniture and
wooden containers. |
Texture |
Texture is fine and even, with straight or only shallowly interlocked grain. |
Density |
The timber is a Heavy Hardwood with a density of 655-1,155 kg/m3 air dry. |
Shrinkage |
Shrinkage is high, especially in the tangential
direction. Radial shrinkage averages 1.5% while tangential shrinkage
averages 3.4%. |
Defect |
The timber is generally free from any major defects
except in some logs, which may contain some heart shakes and some
accompanying decay. Compression failure is occasionally present in some
logs. No "pin" or "shot" hole borer attack in the heartwood has been
observed but the sapwood is liable to powder-post beetle attacks.
Surface-checking of the timber is common but not severe. Some resin
pockets may be present. |