Teak

INTRODUCTION

The trade name for the timber of Tectona grandis (Verbenaceae). The local name for the timber is JATI. Teak is not indigenous to Malaysia but it has been trial planted in Malaysia with encouraging results. The sapwood of the timber is yellowish white or pale yellow-brown and up to 50 mm thick and is distinct from the heartwood, which is dull yellowish when fresh and turning to golden brown or dark greyish brown on exposure, often with greyish or dark coloured streaks.

Also known as Teak (Brunei); Maysak (Cambodia); Teak (India); Jati and Teak (Indonesia); Mai sak, Sak and Teck (Laos); Kyun and Teak (Myanmar); Mai sak, Sak and Teak (Thailand); and Giati (Vietnam).


DENSITY

Teak is a medium weight timber with a density of 610-750 kg/m3 air dry.


NATURAL DURABILITY

The heartwood of teak is rated as durable to very durable depending on the condition of exposure. Stake tests show an average service life in contact with ground of more than 10 years (5.6 years in Malaysia) under tropical conditions and more than 25 years under the temperate conditions. The sapwood is susceptible to attack by powder-post beetles.


PRESERVATIVE TREATMENT

The heartwood is difficult to treat with preservatives.


TEXTURE

Texture is rather coarse and uneven. Grain is straight, wavy or slightly interlocked.


STRENGTH PROPERTIES

The timber is moderately strong.


MACHINING PROPERTIES

Teak is not difficult to work, but requires some effort, mainly because of the presence of silica in the cells. Tools tipped with tungsten carbide are recommended for sawing and planing operations. The wood turns well.


NAILING PROPERTY

The nailing property is rated as good but pre-boring is recommended.


AIR DRYING

Generally, teak dries very well with few defects except that the timber is liable to colour changes and high initial temperature should be avoided. Boards of 13 mm thick take 15 days to air dry from 40% to 15% moisture content, while boards of 25 mm thick take 30 days and boards of 38 mm thick take 50 days.


SHRINKAGE

Teak has very low radial shrinkage of 0.7-1.5% and tangential shrinkage of 1.1-2.5% from green to air dry condition.


USES

The favourable properties of teak make it suitable for a wide variety of purposes. The timber has been used for ship decking and other constructional work in boat building such as furniture and interior fittings of boats. Being classified as very resistant to teredo activity, teak is an excellent timber for bridge building and other construction in contact with water such as docks, quays, piers and floodgates in fresh water. The timber has also been extensively used for house construction like interior and exterior joinery (window, solid panel doors and framing) and is used for floors. Other uses of teak include musical instruments, toys, carving, laboratory and kitchen tables, vats and plywood.


REFERENCE

  1. Wong, T. M. 1982. A Dictionary of Malaysian Timbers. Revised by Lim, S. C. & Chung, R. C. K. Malayan Forest Records No. 30. Forest Research Institute Malaysia, Kuala Lumpur. 201 pp.