Red balau

• Medium to large hardwoods.
• Often buttressed.
• Straight cylindrical bole 30–50m long.

Shorea spp. grow across:

• Indonesia
• Malaysia
• Thailand
• Philippines.

Colour

• Heartwood is red-brown to purple-brown.
• Sapwood is distinctly paler.

Grain

• Grain varies from straight to interlocked.
• Interlocking grain produces striped figure (pattern) on quarter-sawn timber.
• Texture moderately coarse but even.

• Engineering: heavy engineering.
• Construction: framing, flooring, linings, joinery, fencing.
• Decorative: turnery.
• Others: boat building, vats, casks.

• Density: 840kg/m³ at 12% moisture content; about 1.2m³ of seasoned, sawn timber per tonne.
• Strength groups: S3 unseasoned, SD4 seasoned.
• Stress grades: F8, F11, F14, F17 (unseasoned); F11, F14, F17, F22 (seasoned) when visually stress-graded according to AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes.
• Joint groups: JD2 seasoned.
• Shrinkage to 12% MC: shrinkage rates vary considerably between species.
• Unit shrinkage: not available.
• Durability above-ground: Class 4 (life expectancy less than 7 years).
• Durability in-ground: Class 4 (life expectancy less than 5 years).
• Lyctine susceptibility: untreated sapwood is susceptible to lyctine borer attack.
• Termite resistance: not resistant.
• Preservation: sapwood readily accepts preservative impregnation.
• Seasoning: be careful when drying to avoid splits, checks and distortion.
• Hardness: hard (rated 2 on a 6-class scale) to indent and work with hand tools.
• Machining: resinous material gums up cutting edges, otherwise relatively easy to machine and turn.
• Fixing: pre-bore when nailing.
• Gluing: as with most high-density species, machine and prepare surface immediately before gluing.
• Finishing: satisfactory to paint, stain and polish.

General characteristics

• Sapwood: well defined and paler than heartwood.
• Heartwood: purple-red or dark red-brown.
• Texture: moderately coarse, even, interlocked grain; hard to cut across end grain; end cut is generally shiny with a degree of lustre on a dressed surface.

Wood structure

• Vessels: mostly solitary with a few radial or oblique groups, medium size, even and diffuse distribution; tyloses are numerous; vessel lines present.
• Parenchyma (soft tissue): apotracheal—consists mainly of irregular spaced bands and occasional short tangential lines or diffuse strands; paratracheal—often as incomplete vasicentric strands around the vessels, barely visible by hand lens, scant to well-defined aliform.
• Rays: fine, generally inconspicuous on the radial surface.

Other features

• Burning splinter test: match-size splinter burns to a charcoal.
• Intercellular canals: generally filled with white resin, smaller than the vessels, and arranged in concentric formation.

• 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.