Western red cedar
Thuja plicata. Family: Cupressaceae
British Columbia cedar; western cedar; red cedar
- Large tree grows to 40–55m high and 1–3m in stem diameter.
- Specimens have been recorded at more than 65m high and 5m in stem diameter.
- Typical long tapering form of a North American conifer.
- Bark is relatively thin for such a large tree.
- Fibrous and fissured.
- Natural distribution:
- British Columbia
- United States—Washington, Oregon, Idaho and Montana.
- Readily available as imported timber.
- Heartwood is pale brown to dark brown.
- Sapwood is yellowish white and up to 25mm wide.
- Fine texture and straight grain with distinct growth rings.
- Construction: sawn timber in cladding, linings, joinery and shingles.
- Decorative: indoor and outdoor furniture, turnery, joinery, carving.
- Others: beehives, venetian blinds, roller blinds, light boat building.
- Density: 380kg/m3 at 12% moisture content; about 2.6m3 of seasoned sawn timber per tonne.
- Strength groups: S<7 unseasoned, SD8 seasoned.
- Stress grades: F4, F5, F7, (unseasoned); F4, F5, F7, F8 (seasoned) when visually stress-graded according to AS 2858—2008 : Timber—Softwood–Visually graded for structural purposes.
- Joint groups: JD5 seasoned.
- Shrinkage to 12% MC: 3.0% (tangential), 1.5% (radial).
- Unit shrinkage: not available.
- Durability above ground: Class 2 (life expectancy 15–40 years).
- Durability in-ground: Class 2 (life expectancy 15–25 years).
- Lyctine susceptibility: sapwood not susceptible to lyctine borer attack.
- Termite resistance: resistant.
- Preservation: rarely enough sapwood to warrant preservation; penetration of heartwood by preservatives 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: machines, and turns well, to a smooth surface.
- Fixing: ferrous fastenings and fittings may be corroded by wood extractives if exposed to the weather.
- Gluing: satisfactorily bonds using standard procedures.
- Finishing: readily accepts paint, stain and polish.
- Sapwood: yellowish white, distinct from heartwood.
- Heartwood: pink-brown to dull brown, often with darker brown streaks.
- Texture: fine with typical earlywood/latewood bands; straight grain.
- Growth rings: distinct, visible without a lens; abrupt latewood to earlywood transition; latewood bands are much narrower than earlywood bands.
- Vessels: absent.
- Parenchyma (soft tissue): not visible with a hand lens.
- Rays: fine, visible only with a hand lens.
- Burning splinter test: match-size splinter burns completely to a grey-black, fine filament.
- Odour: characteristic sweet and fragrant cedar.
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, 2008, AS 2082—2008: Timber—Softwood—Visually stress-graded for structural purposes, Standards Australia International, Strathfield, NSW.
- Last reviewed: 12 Dec 2018
- Last updated: 12 Dec 2018