Yakal Timber

General characteristics
Sapwood. Well-defined and paler than heartwood.
Heartwood. Yellow brown, brown, reddish brown
Texture. Moderately coarse, even, grain interlocked, hard to cut across end grain; end cut generally shiny; both species show 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 numerous.  Vessel lines present.
Parenchyma. Apotracheal - consisting 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. A match size splinter burns to an ash.
Intercellular canals: Generally filled with white resin, smaller than the vessels, arranged in concentric formation.

Identification features

Engineering. Heavy engineering.
Construction. Framing, flooring, decking, linings, joinery, fencing.
Decorative. Turnery.
Others. Boat building, vats, casks.

Uses

Density. 900 kg/m3 at 12 % moisture content; approximately 1.1 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 AS2082-2000, 'Visually stress-graded hardwood for structural purposes'. Joint groups. J2 unseasoned; JD2 seasoned.
Shrinkage to 12% MC. Shrinkage rates varies considerably between species.
Unit shrinkage. Not available.
Durability above-ground. Class 1 - life expectancy >40 years.
Durability in-ground. Class  2 - life expectancy 15 to 25 years.
Lyctine susceptibility. Untreated sapwood is susceptible to lyctine borer attack.
Termite resistance. Not resistant.
Preservation. Sapwood readily accepts preservative impregnation.
Seasoning. Care required when drying to avoid splits, checks, and distortion.
Hardness. Hard (rated 2 on a 6 class scale) in relation to resistance and ease of working with hand tools.
Machining. Resinous material gums up cutting edges, otherwise relatively easy to machine and turn.
Fixing. Pre-boring recommended when nailing.
Gluing. As with most high-density species machining and surface preparation should be done immediately before gluing.
Finishing. Satisfactory in relation to painting, staining and polishing.

Wood properties

Colour. Yellowish brown heartwood, sapwood distinctly paler.
Grain.  Varies from straight to interlocked.  Interlocking grain produces striped figure on quarter-sawn material. Texture moderately coarse but even.

Wood appearance

Medium to large hardwoods, often buttressed, with a straight cylindrical bole between 30 and 50 m long.  These Shorea spp. grow across a diversity of site types in Indonesia, Malaysia, Thailand and the Philippines.

Tree description and natural occurrence

Local names:  yakal, gisok (Philippines)

Family name: Dipterocarpaceae

Botanical names: Shorea spp. Principally S. glauca, S. laevis, S. albida, S. seminis, S. maxwelliana, S. astylosa.

AD/KD-3 YAKAL

Uses : Heavy construction, boat building, vats, casks, decking, linings, joinery, fencing, flooring and framing.