Rose gum

Scientific name

Eucalyptus grandis. Family: Myrtaceae

Other names

Flooded gum; scrub gum

Description

  • Very tall forest tree.
  • Grows 45–55m high.
  • Stem is 1–2m diameter.

Occurrence

  • Mainly occurs from Newcastle in New South Wales to Bundaberg in Queensland.
  • Smaller stands occur to the west of Mackay in Central Queensland and in the ranges from northwest of Townsville to west of Bloomfield in North Queensland.
  • Grown, in the past, in plantations in Queensland and New South Wales.
  • Sawn timber is readily available.

Appearance

Colour

  • Heartwood is pale pink to red-brown.
  • Sapwood is usually paler but not always clearly different.

Grain

  • Texture is moderately coarse.
  • Grain is mainly straight with no pronounced figure (pattern).

Uses

  • Construction: sawn timber in general house framing, cladding, internal and external flooring, mouldings, linings, joinery, fascia and barge boards.
  • Decorative: internal quality furniture, outdoor furniture, joinery, carving, turnery.
  • Others: structural plywood, boat building (framing components, planking, decking); used, in the past, for boat oars, dowel rods, broom handles, brush ware, fruit cases.

Properties

  • Density: varies with wood maturity—averages about 800kg/m3 at 12% moisture content; about 1.2m3 of seasoned sawn timber per tonne.
  • Strength groups: 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: J3 unseasoned, JD2 seasoned.
  • Shrinkage to 12% MC: 7.2% (tangential), 4.0% (radial).
  • Unit shrinkage: 0.34% (tangential), 0.25% (radial)—these values apply to timber reconditioned after seasoning.
  • Durability above-ground: Class 2 (life expectancy 15–40 years).
  • Durability in-ground: Class 3 (life expectancy 5–15 years).
  • Lyctine susceptibility: sapwood not 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; be careful in the early stages of drying to avoid collapse and surface checking.
  • Hardness: moderate (rated 3 on a 6-class scale) to indent and work with hand tools.
  • Machining: machines, and turns well, to a smooth surface.
  • Fixing: no difficulty using standard fittings and fastenings.
  • Gluing: satisfactorily bonds using standard procedures.
  • Finishing: readily accepts paint, stain and polish.

Identification features

General characteristics

  • Sapwood: light brown, usually paler than heartwood.
  • Heartwood: pink to red-brown.
  • Texture: open, uniform texture, grain usually straight or slightly interlocked.

Wood structure

  • Growth rings: absent.
  • Vessels: large, visible without a lens; number varies, diffusely distributed; diagonal chains are common; prominent vessel lines; cells mostly open but tyloses are common in mature wood.
  • Parenchyma (soft tissue):scarce.
  • Rays: fine, visible only with a lens.

Other features

  • Burning splinter test: match-size splinter burns with difficulty to charcoal.

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.