BANGKIRAI (Shorea laevis)
General
Bangkirai (or sometimes named Balau) is a highly rated
timber that is frequently used for trusses and structural wood members in
areas where termites habitat, however, it is fiction to believe that
Bangkirai is 100% termite resistant as many others tend to
believe. While the
heartwood is not susceptible to termite attacks, sapwood positively is.
Refer to :
http://www2.hawaii.edu/~entomol
The remedy: build with sole
Bangkirai heartwood to protect your unit from termite attacks......Well,
that is a fairy tale. Not one Indonesian timber supplier is willing to
supply Bangkirai heartwood only (normally reddish in color), unless a very
high price will be paid for the timber. They will mix the batch with sap
wood (which is pale yellow), or supply sap wood only. Conclusion: You shall
never believe that a house built from Bangkirai is not susceptible to
termite attacks, at least we are not promoting this.
Untreated Bangkirai can be left in the open for more than
20 years. When Bangkirai is treated on a at least a 2-year recurrent basis
the life time is in fact indefinite.
Appearance
The wood texture of Bangkirai ranges from fine to rather
coarse. The grain is straight or interlocked. The wood surface is
smooth or alternately smooth and rough owing to the interlocked grain. Wood
surface is glossy. Reddish heartwood and yellowish pale to light brown
sapwood. Bangkirai when kiln dried may show some minor cracks
after the process. These cracks will open and close as the surrounding
humidity changes. When untreated Bangkirai is left in the open it will
turn black.
Physical properties
Bangkirai has a high strength and durability, is hard and
heavy with high stiffness and shock resistance. Excellent decay
resistance and dimensional stability. However, Bangkirai will show tiny
cracks due to its natural tendency to shrink a bit over time (even after
kiln drying). It is therefore less suitable for the use in doors, windows,
flooring and/or sidings, in particular in an arid environment. Nonetheless,
if such tiny cracks are accepted (giving it an antique look), Bangkirai is
an extremely durable hardwood and will last a life time. Bangkirai
comes in two classes. A and B, whereas A is heartwood and B=sapwood.
Main use
Flooring beams, construction members, railway sleepers,
electric poles.
