Red cedar

Scientific name

Toona ciliata, syn. T. australis, Cedrela australis, C. toona, C. toona var. australis. Family: Meliaceae

Local name

Cedar

Description and natural occurrence

A tall, deciduous tree up to 40 m in height and 1-2 m in stem diameter. Mature trees can be 3 m in diameter. The trunk is often irregular in cross-section and older trees are often buttressed to some distance up the trunk. The bark is grey or brown, very scaly and rough, and sheds in oblong pieces.

Red cedar is found in rainforests along the east coast of Australia. The main areas of distribution are between Ulladulla, in New South Wales, and Gympie, in Queensland. Farther north it occurs on the Eungella Range west of Mackay and the Atherton Tableland. Outside Australia it extends to Papua New Guinea and the Philippines.

Availability of this timber is now limited.

Wood appearance

Colour. The heartwood ranges from pink to deep red-brown. Sapwood is usually yellowish-white in colour.

Grain. Coarse, open and usually straight. The occasional presence of wavy interlocked grain can produce an attractive fiddleback figure. Growth rings are obvious in back sawn timber.

Wood properties

Density. 450 kg/m3 at 12% moisture content; approximately 2.2 m3 of seasoned sawn timber per tonne.

Strength groups. (S7) unseasoned; SD8 seasoned.

Stress grades. F4, F5, F7 (unseasoned) F4, F5, F7, F8 (seasoned), when visually stress graded in accordance with AS 2082:2000, 'Timber - Hardwood - Visually stress-graded for structural purposes'.

Joint groups. J5 unseasoned; JD5 seasoned.

Shrinkage to 21% MC. 4.1% (tangential) 2.2% (radial).

Unit shrinkage. 0.2% (tangential); not available for radial. This value applies to timber reconditioned after seasoning.

Durability above-ground. Class 2 - life expectancy 15 to 40 years.

Durability in-ground. Class 2 - life expectancy 5 to 15 years.

Lyctine susceptibility. Untreated sapwood susceptible to lyctid borer attack.

Termite resistance. Not resistant.

Preservation. Sapwood readily accepts preservative impregnation but penetration of heartwood is negligible using currently available commercial processes.

Seasoning. Can be satisfactorily dried using conventional air and kiln seasoning methods.

Hardness. Very soft (rated 6 on a 6 class scale) in relation to indentation and ease of working with hand tools.

Machining. The timber will dress and mould to a smooth finish with sharp blades and cutters. When turned, some surface woolliness can occur. Sawdust can irritate nose and throat.

Fixing. No difficulty has been experienced with the use of standard fittings and fastenings.

Gluing. Can be satisfactorily bonded using standard procedures.

Finishing. Will readily accept stain, polish and paint. Because of the coarse texture of the wood, filling may be necessary before finishing.

Uses

Decorative. Furniture, plywood, shop and office fixtures, turnery, carving, inlay work, picture frames, lining, moulding, joinery.

Others. Boat building (light), marine plywood, coach and vehicle building. Has been used for sporting goods, aircraft construction (seaplanes), pattern making, templates, blind rollers, venetian blind slats, gunstocks. High-quality colonial and antique furniture made from this species is much prized.

Identification features

General characteristics

Sapwood. Yellowish-white to light grey.

Heartwood. Pink to dark red-brown.

Texture. Coarse, vessel lines prominent on backsawn surfaces.

Wood structure

Growth rings. Often prominent due to its ring porous structure.

Vessels. Medium to large; arranged in short radial multiples with a distinct tendency to decrease in diameter from earlywood to latewood.

Parenchyma. Indistinct under a lens but some terminal banding occurs.

Rays. Visible without a lens.

Intercellular canals. Visible under a lens in some specimens.

Other features

Burning splinter test. A match size splinter burns to a full white ash.

Figure. Prominent on back-sawn surfaces due to the ring porous structure.

Odour. Heartwood has a pleasant and distinctly spicy aroma.

Further reading

Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, 'Forest trees of Australia', 5th edn, CSIRO Publishing, Collingwood Australia.

Bootle, K 2005, 'Wood in Australia: types, properties and uses', 2nd edn, McGraw-Hill, Sydney.

Hopewell, G (ed.) 2006, 'Construction timbers in Queensland: properties and specifications for satisfactory performance of construction timbers in Queensland, Class 1 and Class 10 buildings', books 1 and 2, Department of Primary Industries and Fisheries, Brisbane.

Ilic, J 1991, 'CSIRO atlas of hardwoods', Crawford House Press, Bathurst, Australia.

Standards Australia, 2000, 'AS 2082-2000: Timber - hardwood - visually stress-graded for structural purposes', Standards Australia.

Last updated 06 August 2010