THE EXPANSION AND CONTRACTION COEFFICIENT

By using the expansion and contraction coefficient in the table, it is possible to calculate the probable variation in the width of a piece of wood board. The formula is as follows:


Expansion and Contraction Coefficient Cherry..........0.00248
Walnut..........0.00274
Ash..........0.00274
Yellow Birch..........0.00338
Maple..........0.00353
White Oak..........0.00365
Red Oak..........0.00369
Beech..........0.00431




WIDTH OF THE BOARD
X COEFFICIENT OF THE SPECIES
X THE VARIATION IN THE % OF MOISTURE CONTENT
= VARIATION IN THE BOARD

EXAMPLE USING MAPLE WOOD

2.5" BOARD
X 0.00353 COEF. OF MAPLE
X 2.4 VAR. IN % OF MC*
= 0.02118" or APPROXIMATELY 1/64"

Copyright © 2005 THE HARDWOOD FLOORING CENTRE