Timber species
06 White beech
Botanical names: Gmelina fasciculiflora, G. leichhardtii, G. dalrympleana
Family name: Verbenaceae
Local names: beech, grey teak
Tree description and natural occurrence
A large tree attaining a height of 40 m and a stem diameter of 1.5 m. It has a straight slender trunk, usually circular in cross-section, often flanged at the base but not prominently buttressed. The bark is approximately 10 mm thick, is coloured light grey to dark grey and is rough and scaly with the scales generally angular but occasionally rounded.
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. 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 of these species is not readily available. Other species of Gmelina are imported from PNG, Solomon Islands and Fiji.
Wood appearance
Colour. The heartwood ranges from pale straw to light grey-brown. There is no noticeable colour difference between sapwood and heartwood.
Grain. A firm, close grained, slightly greasy wood. At times it has interlocking grain. There is no pronounced figure or sheen except for a glistening effect on dressed surfaces due to tyloses in the vessel lines.
Wood properties
Density. 515-545 kg/m3 at 12 % moisture content; approximately 1.8 m3 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.
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 in accordance with AS 2082:2000, 'Visually stress-graded hardwoods for structural purposes.'
Joint groups. J4 unseasoned. JD4 seasoned.
Shrinkage to 12% MC. 3.7 percent (tangential); 1.6 percent (radial). These values are for G. leichhardtii only.
Unit shrinkage. 0.26 percent (tangential); 0.15 percent (radial). These values apply to timber of G. leichhardtii reconditioned after seasoning.
Durability above-ground. Class (1) - life expectancy > 40 years.
Durability in-ground. Class 1 - life expectancy > 25 years.
Lyctine susceptibility. Untreated sapwood susceptible to lyctine borer attack.
Termite resistance. Not resistant.
Preservation. Sapwood readily accepts preservative impregnation but penetration of heartwood is negligible using currently available commercial processes.
Seasoning. Air seasons very slowly. Requires mild schedules for satisfactory kiln drying.
Hardness. Soft (rated 5 on a 6 class scale) in relation to indentation and ease of working with hand tools.
Machining. Machines well due to its slightly greasy nature.
Fixing. Because of the natural acidity of this species, non-corrosive fittings and fastenings should be used.
Gluing. Can be satisfactorily bonded using standard procedures.
Finishing. Will readily accept stain, polish and paint.
Uses
Decorative. Furniture, joinery, carving, turnery, picture frames. Considered the premier carving timber in Queensland.
Others. Boat building (decking, planking). Has been used for draughtsperson's implements, templates, pattern making, cask bungs, brush stock, venetian blind slats, beehives. Was used to some extent in general building framing in the early to mid 1900s, and in flooring, lining, mouldings, joinery and cladding, but use in such applications has been very infrequent for some decades.
Identification features
General characteristics
Sapwood. Not distinctly different in colour from heartwood.
Heartwood. Pale straw to light grey-brown.
Texture. Medium to coarse, grain often interlocked.
Wood structure
Growth rings. Absent.
Vessels. Medium in size, barely visible without a lens; many solitary but some in short radial multiples or groups of 2 or 3. Vessel lines distinct. Tyloses common; whitish deposits also common in vessels and sometimes in rays; sometimes visible without a lens on longitudinal surfaces.
Parenchyma. 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 cuts this species across the grain with distinctive ease, leaving a very smooth surface with a soapy feel.
For information on technical terms consult Timber Species note No.1.
Further reading
Boland, D.J., Brooker, M.I.H., Chippendale, G.M., Hall, N., Hyland, B.P.M., Johnston, R.D., Kleinig, D.A. and Turner, J.D. (1984). Forest Trees of Australia. CSIRO, Australia.
Bootle, K. (2005). Wood in Australia. Types, properties and uses, (2nd edition). The McGraw-Hill Companies.
Hopewell, G. (Ed) (2006). Construction timbers in Queensland: properties and specifications for satisfactory performance of construction timbers in Queensland, Class1 and Class10 buildings (Books 1 and 2), Department of Primary Industries and Fisheries, Brisbane.
Ilic, J. (1991). CSIRO Atlas of Hardwoods. Crawford House Press.
Standards Australia (2000). AS 2080-2000: Timber - Hardwood - Visually stress graded for structural purposes, Australian Standard, distributed by SAI Global Limited.
Last updated 21 December 2006
