The Standard Malaysian Name for the timber of Koompassia excelsa (Leguminosae). Vernacular names applied include kayu raja (Sarawak), mengaris (Sabah) and tapang(Sarawak). This is a monospecific timber. The sapwood is buff-coloured or yellow-brown, often with a pink tinge and is sharply differentiated from the heartwood, which is reddish brown to deep brick-red-brown when fresh and darkens with age to a deep chocolate-brown.
Also known as Mengaris (Brunei); Bengaris, Mengaris, Menggeris, Sialang, Tualang and Wehis (Indonesia); Koompassia (Papua New Guinea); Ginoo and Manggis (Philippines); and Tulae and Yuan (Thailand).
DENSITY
The timber is a Medium Hardwood with a density of 800-865 kg/m3 air dry.
NATURAL DURABILITY
Tualang is classified as moderately durable under exposed conditions. The durability rating is based on the standard graveyard tests conducted at the Forest Research Institute Malaysia (FRIM) on specimens of dimension 50 mm x 50 mm x 600 mm. In the first series of such tests, all 6 specimens were completely destroyed after 3.5 years (Foxworthy & Woolley, 1930). In the second test, 60 specimens were used and the average service life was 3 years (Jackson, 1965). The sapwood of the timber is susceptible to both powder-post beetle and fungi attacks, while the heartwood is readily destroyed by termites.
PRESERVATIVE TREATMENT
The timber is amenable to preservative treatment and is classified as easy to treat.
TEXTURE
Texture is rather coarse but even except in areas where included phloem occurs. Grain is interlocked, often deeply interlocked.
COMMON USES
Heavy structural use, Mouldings, Cladding, Decking and for House Roofing (Roofing Timber).