Tectona grandis. Family: Verbenaceae
Djati; jati (Indonesia); kyun (Myanmar); sagwan (India); teck; mai sak (Thailand); giati (Vietnam); teca (Brazil)
- 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:
- Papua New Guinea
- Solomon Islands
- West Indies.
- 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 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.
- Sapwood: pale yellow, readily distinguished from heartwood.
- Heartwood: brown to golden brown; sometimes streaky.
- Texture: non-uniform, moderately coarse, straight grain and greasy feel.
Research and resources
- 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.
- Last reviewed: 12 Dec 2018
- Last updated: 12 Dec 2018