Silvertop ash

Scientific name Eucalyptus sieberi syn. E. sieberana. Family: Myrtaceae
Local names

Silvertop, coast ash, ironbark (Tasmania)

Description and natural occurrence

A tall tree to 45 m with hard, deeply furrowed dark grey to black bark, covering the trunk, and contrasting smooth-barked branches above.

It is found in the tablelands, central coastal and south coastal New South Wales, through eastern Victoria and the coastal Gippsland districts, and in the north-eastern corner of Tasmania.

Wood appearance

Colour
Heartwood pale brown, sometimes with a tinge of pink; sapwood narrow and indistinguishable. Pin hole borer discolouration common.

Grain
Grain often interlocked, medium texture.

Wood properties

Density
820 kg/m3 per at 12% moisture content. Approximately 1.2 m3 of seasoned, sawn timber per tonne.

Strength groups
S3 unseasoned; SD3 seasoned.

Stress grades
F8, F11, F14, F17 (unseasoned), F14, F17, F22, F27 (seasoned), when visually stress-graded in accordance with AS 2082-2000, Timber - Hardwood - Visually stress-graded for structural purposes.

Joint groups
J2 unseasoned; JD2 seasoned.

Shrinkage to 12% MC
Approximately 10% (tangential); 6% (radial).

Unit shrinkage
Not available.

Durability above-ground
Class 2 - life expectancy 15 to 40 years.

Durability in-ground
Class 3 - life expectancy 5 to 15 years.

Lyctine susceptibility
Untreated sapwood is not susceptible to lyctid borer attack.

Termite resistance
Not resistant.

Preservation
Sapwood accepts preservative impregnation.

Seasoning
This timber is more difficult to season without degrade than the Tasmanian oaks, and the rate of drying is slower. Collapse is significant and reconditioning is desirable.

Hardness
Hard (rated 2 on a 6 class scale) in relation to indentation and ease of working with hand tools.

Machining
Machines well.

Fixing
No difficulty has been experienced with the use of standard fittings and fastenings.

Gluing
Can be satisfactorily bonded using standard procedures.

Finishing
Readily accepts paint, stain and polish.

Uses

Construction
General construction, flooring, panelling.

Decorative
Suitable for steam bending, outdoor furniture.

Others
Woodchip for paper production, shingles.

Identification features

General characteristics

Sapwood
Light brown in colour and not distinct from the heartwood.

Heartwood
Pale brown with occasional gum veins and/or flecks, sometimes with pink tints.

Texture.
Moderately open, growth rings visible in some specimens, grain sometimes interlocked.

Wood structure

Vessels.
Medium to small, solitary, tylosed, vessel lines conspicuous.

Parenchyma.
Not visible with hand lens.

Rays.
Fine, visible as a darker fleck on radial surfaces.

Other features

Burning splinter test.
A match size splinter burns to charcoal with no ash.

Further reading

Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD (1984). Forest Trees of Australia. CSIRO, Australia.

Bootle, K (2005). Wood in Australia. Types, properties and uses, (2nd edition). The McGraw-Hill Companies.

Queensland Goverment (2010). Construction timbers in Queensland: properties and specifications for satisfactory performance of construction timbers in Queensland, Class 1 and Class 10 buildings (Books 1 and 2). Queensland Government, Brisbane.

Ilic, J (1991). CSIRO Atlas of Hardwoods. Crawford House Press.

Standards Australia (2000). AS 2082-2000: Timber - Hardwood - Visually stress-graded for structural purposes, Australian Standard, distributed by SAI Global Limited.

Last updated 05 October 2012