SHOREA

Other names
Light- to medium-weight Shorea timbers with predominantly yellow or yellow-brown heartwood are known as yellow meranti in Malaya and Sarawak and as yellow seraya in Sabah. The only species of this group in the Philippines, known locally as kalunti, is classed as yellow lauan for trade purposes.

Distribution
From the southern tip of Thailand, through Malaya, Sumatra and the island of Borneo to Mindanao in the Philippines.

The tree
The trees are mostly medium sized to large, with long cylindrical boles, sometimes 0,9-1,5m in diameter above the buttresses.

The timber
Being a mixture of species, the commercial timber is variable in colour, weight and texture. Heartwood is typically a dull-yellow or yellow-brown, darkening somewhat on prolonged exposure; it is liable to discoloration in contact with iron under moist conditions. The grain is shallowly interlocked and the texture moderately coarse, although somewhat finer than that of red meranti.

Strength
Like other types of meranti the timber is somewhat variable in strength. On average, it is of the order of 10-15per cent superior to light-red meranti/seraya in stiffness and resistance to bending, and about 25 per cent tougher, harder and more resistant to shear and splitting.

Seasoning and movement
In thicknesses up to 50mm the timber dries slowly but well, apart from some tendency to cup; in thicker sizes moisture movement is slow and there is some risk of honeycombing.

Durability
Heartwood is rated moderately durable with regard to decay, but is not resistant to termite attack. Logs are susceptible to ambrosia (pinhole borer) beetle damage and, on drying; sapwood is liable to attack by powder-post beetles. Heartwood is extremely resistant to preservative treatment even under pressure.

Working qualities
The timber works easily with all hand and machine tools and has only a slight blunting effect. A good finish is obtained provided tools are used, although to avoid tearing when planning quartered surfaces, a cutting angle of twenty degrees is recommended. For rip sawing, satisfactory results are obtained with saws having 54 teeth and a 25 degree hook.

Uses
Though slightly harder and heavier than light-red meranti, yellow meranti can be used for similar purposes, namely joinery, light structural work where some variation in colour, grain and texture is permissible, and for plywood.

Other species of interest
White meranti is the trade name for a distinct group of Shorea species with nearly white heartwood, darkening to a buff colour, widely distributed in South-East Asia. The wood has a high silica content which makes it difficult to saw but it can be peeled for the manufacture of plywood. White meranti should not be confused with white seraya.