Botanical Name: Intsia spp

Origin: Papua New Guinea, Indonesia

Species Overview: 
The heartwood is yellowish-brown, brown or dark red, red-brown, turning to a dark red-brown with age. The wood is hard and heavy, the texture is moderately coarse but even and the grain may be straight or interlocked and is often wavy. Sulphur-yellow and dark coloured deposits are characteristic of the species and can be commonly seen in the vessel cavities. Timber ‘bleeds’ when wet producing dark red-brown stain.

Main Uses:

• Landscaping & heavy construction
• Flooring
• Decking
• Exterior joinery & construction
• Interior joinery & furniture
• Mouldings

Highly suitable for premium heavy construction due to its low shrinkage and durability.

Working Properties:
Saws well, however, with the fairly high incidence of gum, saws tend to become clogged. It planes well but there is a tendency for the grain to tear out in quarter-sawn material. A reduction in the cutting angle to 20º is beneficial. The wood tends to split when nailing but holds screws well and can be stained and polished reasonably well, however, patches of oil that exude may affect the finish. The yellow deposits are soluble in water and the dye produced does stain. If, however, early attention is given to any staining it can generally be removed by scrubbing with milk or lactic acid.

Mechanical Properties:
Kwila has high bending strength, crushing strength and stiffness, with medium resistance to shock loads. It has a poor stream bending classification due to exudation of oil.

INSTALLATION

Before commencing deck construction confirm with your local council that the proposed deck complies with council regulations and that its design and construction methods are compliant with the New Zealand Building Code.

Ensure your deck design allows for adequate ground clearance i.e. a minimum of 450mm and that the structure is well ventilated allowing good airflow beneath your deck. Building too close to the ground and or closing in the sides of your deck can cause excessive board top versus board underside moisture variations which can lead to warping or cupping of the decking boards. This is particularly important when using decking boards wider than 90mm, as the greater board area amplifies these risks.

• Joist spacing’s should be no more than 400-450mm.
• Gaps between each board (row) should be no less than 4mm for 90x19mm and 6mm for 140x19mm boards
• Gaps at abutments should be no less than 3mm.
• Decking board butts can be joined end to end.

Durability (Above Ground): Durable

Density
Density Air Dried 870 kg/m3

Shrinkage
Shrinkage Radial 0 – 2.0 % (Green to 12% MC)
Shrinkage Tangental: 1.0 – 3.0 % (Green to 12% MC)

Stability
Stability Kiln Dried Very stable
Stability Green: Stable