The rate of expansion for ALTWOOD^® is not constant over the entire recommended range of temperatures for the product, which is -50°C to +80°C (-58°F to +176°F). Below is a simple chart showing the expansion values for different temperature ranges.

Temperature Range (Material)	Expansion Value (per 10°C / 18°F)	Expansion of 12' Length (per 10°C / 18°F)
-50°C to +80°C (-58°F to +176°F)	0.1%	9/64"
-30°C to +60°C (-22°F to +140°F)	0.08%	7/64"
-20°C to +50°C (-4°F to +122°F)	0.06%	3/32"
-10°C to +50°C (+14°F to +122°F)	0.04%	1/16"

Example 1
For installation in a region where temperatures range from -10°C to +50°C (14°F to 122°F), and the installation temperature of the ALTWOOD^® is -10°C (14°F) the space required between two 12 foot boards butted end to end would be 6 times 1/16" = 3/8".

Example 2
For installation in a region where temperatures range from -10°C to +50°C (14°F to 122°F), and the installation temperature of the ALTWOOD^® is +10°C (50°F) the space required between two 12 foot boards butted end to end would be 4 times 1/16" = 1/4".

Example 3
For installation in a region where temperatures range from -10°C to +50°C (14°F to 122°F), and the installation temperature of the ALTWOOD^® is +20°C (68°F) the space required between two 12 foot boards butted end to end would be 3 times 1/16" = 3/16".

Please note that unless ALTWOOD^® is stored in shade or is covered before installation, the temperature of the material may be much higher or lower than the ambient air temperature.