Solid
timber from a domestic timber yard will normally contain about 17 per
cent moisture (by weight). After a few weeks in a centrally heated
house, the moisture will drop to 8-10 per cent. As a result, the wood
will shrink slightly and may also develop a curve. The wider the board
the greater the problem.
Preferably
avert this problem altogether by buying from us with correct MC
specified ie 8-12% standard but can be 6-10% on request.
The shrinkage takes place along the length of the annular growth rings
which follow the circular shape of the tree trunk. In most cases the
rings are much shorter near one face of the board than the other. The
longer rings shrink most and the shorter least, causing the board to
curve across its width.
The straighter the rings in a board, the less it will curve, so look
for boards that have the rings running almost vertically through the
thickness. CALLED QUARTER SAWN. Where growth rings show running
across the width of the board this is called FLATSAWN.
No matter how carefully something is made, wood that is too wet will
develop distortions. So store timber in house for at least two or three
weeks to allow it to dry out. OR EQUALISE.
Store boards flat, one above the other, with pieces of wood between them so that air can circulate.
