DIMENSIONAL
WOOD STABILITY
The
numbers in the chart reflect the dimensional
change coefficient for the various species,
measured as tangential shrinkage or swelling
within normal moisture content limits
of 6-14 percent. Tangential change values
will normally reflect changes in plainsawn
wood. Quartersawn wood will usually be
more dimensionally stable than plainsawn.
The
dimensional change coefficient can be
used to calculate expected shrinkage or
swelling. In actual practice, however,
change would be diminished in a complete
floor, as the boards’ proximity to each
other tends to restrain movement.
What
all this is really saying is that the
lower the change coefficient, the less
your floor will move and the less your
floor moves, the better.
Although
some tropical woods such as Australian
cypress, Brazilian cherry, merbau and
wenge appear in this chart to have excellent
moisture stability compared to domestic
oak, actual installations of many of these
woods have demonstrated significant movement
in use. To avoid problems later, extra
care should be taken to inform potential
users of these tendencies prior to purchase.
|
Species |
Change Coefficient |
|
Mesquite |
.00129 |
|
Merbau |
.00158 |
|
Cypress |
.00162 |
|
Padauk |
.00180 |
|
Teak |
.00186 |
|
Wenge |
.00201 |
|
Purpleheart |
.00212 |
|
Mahogany |
.00238 |
|
|
|
|
Cherry |
.00248 |
|
HeartPine |
.00263 |
|
Pine |
.00265 |
|
Fir |
.00267 |
|
Ash |
.00274 |
|
Walnut |
.00274 |
|
Brazilian Cherry |
.00300 |
|
Pecan |
.00315* |
|
Birch |
.00338 |
|
Maple |
.00353 |
|
White Oak |
.00365 |
|
Red Oak |
.00369 |
|
Jarrah |
.00396 |
|
Beech |
.00431 |