Coronavirus (COVID-19) update: We are currently updating information following recent Queensland and Australian Government announcements. Find assistance and support for coronavirus affected businesses and industries.

Forest red gum

Scientific name

Eucalyptus tereticornis, E. blakelyi ssp. blakelyi. Family: Myrtaceae

Other names

Blue gum; red gum; red iron gum

Description

  • Medium to tall forest tree.
  • Grows 20–50m high.
  • Stem diameter up to 2m.
  • Trunk is usually straight and clear for more than half its height.
  • Major limbs are more steeply inclined than in other eucalypt species.
  • Bark surface is smooth with white, grey and bluish patches from bark shedding.
  • Rough, dead bark (dark grey to black) is retained at the base of the stem.

Occurrence

  • The most extensive latitudinal distribution of the Eucalyptus genus.
  • Extends from coastal south-eastern Victoria to northwest of Laura in North Queensland.
  • Found in southern Papua New Guinea.

Appearance

Colour

  • Heartwood ranges in colour from red to dark red.
  • Sapwood is distinctly paler in colour.

Grain

  • Moderately coarse, uniform textured, usually interlocked.

Uses

  • Engineering: sawn and round timber used to construct wharves and bridges, railway sleepers, cross arms, poles, piles (including wharf piles), mining timbers.
  • Construction: sawn timber in general house framing, cladding, fascia and barge boards, internal and external flooring, linings, joinery, fencing, landscaping, retaining walls.
  • Decorative: outdoor furniture, turnery, joinery.
  • Others: structural plywood, boat building (keel and framing components, planking), coach, vehicle and carriage building.

Properties

  • Density: E. tereticornis is 1010kg/m3 and E. blakelyi ssp. blakelyi is 1055kg/m3 at 12% moisture content; about 1.0m3 of seasoned sawn timber per tonne.
  • Strength groups: E. tereticornis—S3 unseasoned, SD4 seasoned; E. blakelyi ssp. Blakelyi—(S3) unseasoned, (SD4) seasoned.
  • Stress grades: F8, F11, F14, F17 (unseasoned); F11, F14, F17, F22 (seasoned), when visually stress-graded according to AS 2082—2000: Timber—Hardwood—Visually stress-graded hardwood for structural purposes.
  • Joint groups: J1 unseasoned, JD1 seasoned.
  • Shrinkage to 12% MC: 8.6% (tangential), 4.8% (radial).
  • Unit shrinkage: 0.34% (tangential), 0.25% (radial)—these values apply to timber reconditioned after seasoning.
  • Durability above-ground: Class 1 (life expectancy more than 40 years).
  • Durability in-ground: Class 1 (life expectancy more than 25 years).
  • Lyctine susceptibility: E. tereticornissapwood not susceptible to lyctid borer attack; E. blakelyi ssp. blakelyi is susceptible to lyctid borer attack.
  • Termite resistance: resistant.
  • Preservation: sapwood readily impregnates with preservative, unlike the heartwood, where penetration is negligible using available commercial processes.
  • Seasoning: satisfactorily dries using conventional air and kiln seasoning.
  • Hardness: very hard (rated 1 on a 6-class scale) to indent and work with hand tools.
  • Machining: interlocked grain often makes it difficult to dress cleanly on the radial surface.
  • Fixing: no difficulty using standard fittings and fastenings.
  • Gluing: as with most high-density species, machine and prepare surface immediately before gluing.
  • Finishing: readily accepts paint, stain and polish.

Identification features

General characteristics

  • Sapwood: grey or cream red, distinct from heartwood.
  • Heartwood: ranges from light to dark red.
  • Texture: uniform with interlocked grain.

Wood structure

  • Vessels: small to medium, uniformly distributed; seasonal growth zones often evident; tyloses; vessels appear pink-yellow due to associated parenchyma and deposits when viewed by lens in cross section.
  • Parenchyma (soft tissue): abundant and diffuse, containing deposits and some resin.
  • Rays: fine, visible only with a lens.

Other features

  • Burning splinter test: match-size splinter burns slowly to charcoal with no ash.

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.