Red cedar

Scientific name

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

Other names

Cedar

Description

  • Tall, deciduous tree.
  • Grows up to 40m high.
  • Stem is 1–2m diameter; mature trees can be 3m diameter.
  • Trunk is often irregular in cross section.
  • Older trees are often buttressed far up the trunk.
  • Bark is grey or brown, very scaly and rough, and sheds in oblong pieces.

Occurrence

  • Found in rainforests along the east coast of Australia.
  • Mainly between Ulladulla, in New South Wales, and Gympie, in Queensland.
  • Eungella Range west of Mackay and the Atherton Tableland.
  • Papua New Guinea.
  • Philippines.
  • Timber availability is limited.

Appearance

Colour

  • Heartwood is pink to deep red-brown.
  • Sapwood is usually yellowish white.

Grain

  • Coarse, open and usually straight.
  • Occasionally with wavy-interlocked grain that can produce an attractive fiddleback figure (pattern).
  • Growth rings are obvious in back-sawn timber.

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; used, previously in 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.

Properties

  • Density: 450kg/m3 at 12% moisture content; about 2.2m3 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 according to 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—tangential value applies to timber reconditioned after seasoning.
  • Durability above-ground: Class 2 (life expectancy 15–40 years).
  • Durability in-ground: Class 2 (life expectancy 5–15 years).
  • Lyctine susceptibility: untreated sapwood susceptible to lyctid borer attack.
  • Termite resistance: not resistant.
  • Preservation: sapwood readily impregnates with preservative but penetration of heartwood is negligible using available commercial processes.
  • Seasoning: satisfactorily dries using conventional air and kiln seasoning.
  • Hardness: very soft (rated 6 on a 6-class scale) to indent and work with hand tools.
  • Machining: dresses and moulds to a smooth finish using sharp blades and cutters; when turned, some surface woolliness can occur; sawdust can irritate your nose and throat.
  • Fixing: no difficulty using standard fittings and fastenings.
  • Gluing: satisfactorily bonds using standard procedures.
  • Finishing: readily accepts stain, polish and paint.

Identification features

General characteristics

  • Sapwood: yellowish white to light grey.
  • Heartwood: pink to dark red-brown.
  • Texture: coarse, vessel lines prominent on back-sawn surfaces.

Wood structure

  • Growth rings: often prominent due to its ring porous structure.
  • Vessels: medium to large; arranged in short radial multiples that usually decreases in diameter from earlywood to latewood.
  • Parenchyma (soft tissue): indistinct under a lens but will show some terminal banding.
  • Rays: visible without a lens.
  • Intercellular canals: visible under a lens in some specimens.

Other features

  • Burning splinter test: match-size splinter burns to a full white ash.
  • Figure (pattern): prominent on back-sawn surfaces due to the ring porous structure.
  • Odour: heartwood has a pleasant and distinctly spicy aroma.

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 International, Strathfield, NSW.