Botanically, Kwila(Intsia bijuga) belongs to the legume family. Kwila, also known as Merbau, originates from the Pacific region, in particular from the Solomon Islands and Papua New Guinea. In the eastern part of Indonesia, the wood is called “Merbau”. The genus is also found in the Philippines and Malaysia. Kwila grows on well-drained sites in the lower mountain zone.
Heartwood golden brown, later darkening to reddish brown, sapwood narrow and pale yellow. Pores coarse, scattered and hyalinized, storage cells surrounding the pores, often cross-linked as bands, growth zones practically unrecognizable. Pores contain yellowish-white, sometimes also black ingredients. Medullary rays of Kwila are rather inconspicuous, the structure of the hive is visible as fine bands. Alternating torsion present. Homogeneous. Decorative.
Density at u=12% wood moisture is 0.83 t/m³. The shrinkage from the fresh state to u=12% is specified as 2.5 % tangential and 1.3 % radial. Kwila shows very good stamina, comparable to that of Afzelia. The dimensional change per 1% change in wood moisture content is 0.31% in the tangential direction and 0.19% in the radial direction; both low values. However, Kwila is slow to dry and can only be worked with increased force; carbide-tipped tools are recommended. Irritation of the mucous membranes may occur during processing. The bending stiffness is high, the modulus of elasticity is 18,000 N/mm2. Kwila can be kept unprotected in contact with the ground for 15 – 20 years (durability class 1-2).
As water-soluble, brown substances can escape from fresh wood, suitable surface treatment in contact with water (bath, sauna areas) and outdoors is of particular importance.
The wood should therefore be wet-brushed and oiled or varnished before installation.
High-quality construction timber for outdoor use, also framing timber, parquet flooring, stairs, walkways, horticultural timber, instrument making.
| References: |
Terrace deck & strip parquet, LVM insurance, Münster Prefabricated parquet, ESPEN office, Bad Vilbel Parquet, Neven Dumont, Cologne Parquet & stair treads, Falkenstein property, Taunus Exterior cladding, Allianz Tower Frankfurt Balcony covering, private house, Bad Vilbel |
| Sources: |
GOTTWALD 1970: Wood identification of the most important commercial timbers EDDOWS, P.J. 1985: Commercial Timbers of Papua New Guinea SCHWAB, E. 1993: Orientierende Prüfung einiger Holzarten aus PNG, BFH Hamburg, unpublished. |
References:
Terrace deck
Kwila , FSC, 30x140mm
2-layer strip parquet
Kwila, FSC
Architect: hpp, Düsseldorf
Wood type: Kwila,45x130mm
Terrace decking
Balcony decking, Kwila , FSC, 30x140mm
Handrail Salomon Padouk, FSC, 45mm diameter
