Silvertop stringybark

Scientific name

Eucalyptus laevopinea. Family: Myrtaceae

Description

  • Medium-sized, tall hardwood tree.
  • Grows to 40m on favourable sites, with good form.
  • Bark is grey and fibrous up to the upper limbs.
  • Upper limbs are smooth and whitish, giving it the name 'silvertop'.

Appearance

Colour

  • Heartwood is pale brown, and may have pinkish tints.

Grain

  • Close-grained, usually straight.
  • Texture is medium and even.

Uses

  • Construction: structural plywood, framing, general building construction, decking and flooring.

Properties

  • Density: 860kg/m3 at 12% moisture content; about 1.2m3 of seasoned sawn timber per tonne.
  • Strength groups: S2 unseasoned, (SD2) seasoned (brackets indicate provisional value).
  • Stress grades: F11, F14, F17, F22, (unseasoned); F17, F22, F27, F34 (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: about 10.0% (tangential), 6.0% (radial).
  • Unit shrinkage: not available.
  • Durability above-ground: Class 3 (life expectancy 7–15 years).
  • Durability in-ground: Class 3 (life expectancy 5–15 years).
  • Lyctine susceptibility: untreated sapwood not susceptible to lyctid borer attack.
  • Termite resistance: not resistant.
  • Preservation: sapwood readily impregnates with preservative.
  • Seasoning: some collapse and checking occurs.
  • Hardness: hard (rated 2 on a 6-class scale) to indent and work with hand tools.
  • Machining: not hard to work.
  • Fixing: no difficulties using standard fittings and fastenings.
  • Gluing: glues well.
  • Finishing: readily accepts paint, stain and polish.

Identification features

General characteristics

  • Sapwood: pale brown, not easily differentiated from the heartwood.
  • Heartwood: pale brown to brown, may have pink tints.
  • Texture: medium to open, slightly interlocked grain.

Wood structure

  • Vessels: small to medium, mostly solitary, usually forms oblique arrangements, forms growth rings with vessel numbers reducing in the latewood.
  • Parenchyma (soft tissue): none visible through hand lens.
  • Rays: very fine.

Other features

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