White beech

Scientific name

Gmelina fasciculiflora, G. leichhardtii, G. dalrympleana. Family: Verbenaceae

Other names

Beech; grey teak

Description

  • Large tree grows to 40m high.
  • Stem grow to 1.5m diameter.
  • Trunk is straight, slender, usually circular in cross-section, often flanged at the base but not prominently buttressed.
  • Bark is about 10mm thick, light grey to dark grey, rough, and scaly with the scales generally angular but occasionally rounded.

Occurrence

  • Found in rainforests along the east coast of Australia.
  • G. fasciculiflora and G. dalrympleana—Rockingham Bay, Innisfail area, through to Cape York and Torres Strait Islands; sawn timber is imported from Papua New Guinea, Solomon Islands and Fiji.
  • G. leichhardtii—Clyde River, New South Wales to Fraser Island, Queensland. Also further north on the Eungella Range and Mt Elliot (south of Townsville); sawn timber is not readily available.

Appearance

Colour

  • Heartwood is pale straw to light grey-brown.
  • Sapwood and heartwood show no noticeable colour difference.

Grain

  • Firm, close grain, slightly greasy wood.
  • May have interlocking grain.
  • No pronounced figure (pattern) or sheen except for a glistening effect on dressed surfaces due to tyloses in the vessel lines.

Uses

  • Decorative: furniture, joinery, carving, turnery, picture frames; considered the premier carving timber in Queensland.
  • Others: boat building (decking, planking); previously, used for draughtsperson´s implements, templates, pattern-making, cask bungs, brush stock, venetian blind slats, beehives; used in the early–mid 1900s in general building framing, flooring, lining, mouldings, joinery and cladding; but this use has been very infrequent for decades.

Properties

  • Density: 515-545kg/m3 at 12% moisture content; about 1.8m3 of seasoned sawn timber per tonne.
  • Strength groups: G. fasciculiflora and G. leichhardtii—S6, G. dalrympleana—(S7) unseasoned, G. fasciculiflora—(SD6), G. leichhardtii—SD6, G. dalrympleana—(SD7) seasoned (brackets indicate provisional value).
  • Stress grades: G. fasciculiflora and G. leichhardtii—F4, F5, F7, F8; G. dalrympleana—F4, F5, F7 (unseasoned); G. fasciculiflora, G. leichhardtii—F7, F8, F11, F14; G. dalrympleana—F5, F7, F8, F11 (seasoned) when visually stress-graded according to AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes.
  • Joint groups: J4 unseasoned, JD4 seasoned.
  • Shrinkage to 12% MC: G. leichhardtii—3.7% (tangential), 1.6% (radial).
  • Unit shrinkage: G. leichhardtii—0.26% (tangential), 0.15% (radial)—these values apply to timber reconditioned after seasoning.
  • Durability above-ground: Class (1) (life expectancy over 40 years).
  • Durability in-ground: Class 1 (life expectancy over 25 years).
  • Lyctine susceptibility: Untreated sapwood susceptible to lyctine borer attack.
  • Termite resistance: not resistant.
  • Preservation: sapwood readily impregnates with preservative, but penetration of heartwood is negligible using available commercial processes.
  • Seasoning: air seasons very slowly; requires mild schedules for satisfactory kiln drying.
  • Hardness: soft (rated 5 on a 6-class scale) to indent and work with hand tools.
  • Machining: machines well due to its slightly greasy nature.
  • Fixing: due to natural acidity, use non-corrosive fittings and fastenings.
  • Gluing: satisfactorily bonds using standard procedures.
  • Finishing: readily accepts stain, polish and paint.

Identification features

General characteristics

  • Sapwood: not distinctly different in colour from heartwood.
  • Heartwood: pale straw to light grey-brown.
  • Texture: medium to coarse, grain is often interlocked.

Wood structure

  • Growth rings: absent.
  • Vessels: medium, barely visible without a lens; many solitary but some in short radial multiples or groups of 2 or 3; distinct vessel lines; common tyloses; whitish deposits are common in vessels and sometimes in rays; sometimes visible without a lens on longitudinal surfaces.
  • Parenchyma (soft tissue): not visible under a lens.
  • Rays: fine.

Other features

  • Burning splinter test: gives a full, greyish-white to buff coloured ash; burns with a crackling noise.
  • Odour: freshly cut surfaces have a faint sour odour.
  • Cutting: a sharp knife will cut across the grain with distinctive ease, leaving a very smooth surface with a soapy feel.

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.