Teak

• Medium to tall hardwood, growing 45m on favourable sites.
• Usually bole (trunk) is 15m.
• Stem is irregularly shaped and grooved, and typically the leaves are very large.
• Stem diameter averages 1m but can grow up to 2.4m according to locality and conditions.

• Among the most well-known world timbers.
• Occurs naturally in the monsoon forests of:
  • India
  • Myanmar
  • Thailand
  • Vietnam.
• Plantations:
  • Indonesia
  • Papua New Guinea
  • Africa
  • Solomon Islands
  • Fiji
  • West Indies.

Colour

• Heartwood is generally golden brown but can be grey-brown to red-brown.
• Longitudinal streaks are often present due to the ring-porous structure of teak.
• Sapwood is pale yellow, therefore well demarcated.

Grain

• Grain is straight or occasionally interlocked.
• Texture is uneven varying from smooth to coarse due to its ring porosity.

• Construction: flooring, decking, framing, boards, cladding, fascias and barge boards.
• Decorative: lining, panelling, turnery, carving, furniture (both indoor and garden), parquetry.
• Others: best known for its long established use in the boat building industry; extensively used for decking, deckhouses, rails, bulwarks, hatches, weather doors, and planking; also used for cooperage, pipes and chemical vats.

• Density: 670kg/m³ at 12% moisture content; about 1.5m³ of seasoned sawn timber per tonne.
• Strength groups: (S6) unseasoned, (SD6) seasoned.
• Stress grades: F4, F5, F7, F8 (unseasoned); F7, F8, F11, F14 (seasoned) when visually stress-graded according to AS 2082—2000: Timber—Hardwood—Visually stress-graded hardwood for structural purposes.
• Joint groups: JD3 seasoned.
• Shrinkage to 12% MC: 2.2% (tangential), 1.2% (radial).
• Unit shrinkage: not available.
• Durability above-ground: Class 1 (life expectancy more than 40 years).
• Durability in-ground. Class 2 (life expectancy 15–25 years).
• Lyctine susceptibility: untreated sapwood susceptible to lyctid borer attack.
• Termite resistance: resistant.
• Preservation: sapwood will impregnate with preservatives.
• Seasoning: slow drying; drying rates vary between pieces; little degrade; some collapse may occur if you use high temperatures.
• Hardness: firm (rated 4 on a 6-class scale) to indent and work with hand tools.
• Machining: varies, but generally works with moderate ease. Silica present in the timber causes severe blunting of cutting edges—reduce your planing angle to 20° and use saws with tungsten carbide tips.
• Fixing: pre-bore when nailing; holds nails and screws well.
• Gluing: as with most timbers of an oily nature, machine and prepare surface immediately before gluing.
• Finishing: varnishes, polishes and waxes well; readily accepts paint and stains.

General characteristics

• Sapwood: pale yellow, readily distinguished from heartwood.
• Heartwood: brown to golden brown; sometimes streaky.
• Texture: non-uniform, moderately coarse, straight grain and greasy feel.

• Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, Forest trees of Australia, 5th ed., CSIRO Publishing, Collingwood, Australia.
• Bootle, K 2005, Wood in Australia: Types, properties and uses, 2nd ed., McGraw-Hill, Sydney.
• Ilic, J 1991, CSIRO atlas of hardwoods, Crawford House Press, Bathurst, Australia.
• Queensland Government, DAF 2018, Construction timbers in Queensland: Properties and specifications for satisfactory performance of construction timbers in Queensland. Class 1 and Class 10 buildings, Books 1 & 2, Department of Agriculture and Fisheries, Brisbane.
• Standards Australia, 2000, AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes, Standards Australia.