Black Butt Prefinished Flooring
Description and natural occurrence
A moderate to large tree, attaining 40 to 60 m in height and 1 to 2 m in stem diameter. It has a straight slender trunk, circular in cross-section. The bark on the lower part of the trunk is dark grey-brown in colour, fibrous and fissured. Typical smooth gum type bark occurs on branches and the uppermost part of the trunk.
Found in coastal regions from southern New South Wales to Maryborough, Queensland.
Sapwood : Slightly paler than heartwood.
Heartwood : Light brown with occasional pink coloration in some samples.
Texture : Open and uniform. Grain straight but occasionally slightly interlocked. In some cases it has a greasy appearance and feel, similar to but not as pronounced as in tallowwood (E. microcorys).
Growth rings : Absent.
Gum veins : Some pieces may contain gum (kino) veins.
Colour : The heartwood is pale brown with a faint tinge of pink when freshly cut. Sometimes the sapwood is indistinguishable from the heartwood but usually it is slightly paler in colour.
Grain : Moderately coarse textured and uniform.
Air dry density : 930 kg/m3 at 12% moisture content; approximately 1.1m3 of seasoned sawn timber per tonne.
Plantation-grown timber : Age 4 years: 64% mature timber density. Age 11-17 years: 80-88% mature timber density.
Strength groups : S2 unseasoned; SD2 seasoned.
Shrinkage to 12% MC : 7.3% (tangential) 4.3% (radial)
Unit shrinkage : 0.37 % (tangential) 0.26 % (radial). These values apply to timber reconditioned after seasoning.
Durability above-ground : Class 1 – life expectancy over 40 years.
Durability in-ground : Class 2 – life expectancy 15 to 25 years.
Lyctine susceptibility : Sapwood is not susceptible to lyctine borer attack.
Termite resistance : Resistant.
Preservation : Sapwood readily accepts preservative impregnation but penetration of the heartwood is negligible using currently available commercial processes.
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 : As with most high-density species, machining and surface preparation should be done immediately before gluing.
Decorative : Internal quality furniture, outdoor furniture, turnery, parquetry.