Thermal Expansion

All materials expand and contract to some extent with changes in temperature. The Thermal Coefficient of Linear Expansion is expressed in "Inches Per Inch Per Degree Fahrenheit." Example: gypsum board has a coefficient of 9.0 x 10-6 in. per in. per °F. This means that with an increase in temperature of 50°, a gypsum board wall 100 ft. in length will have a linear expansion of .54" or an excess of 1/2". The expansion characteristics of some other building materials are more pronounced; a 50° temperature increase would produce expansion in a 100' length of approx. 3/4" in aluminum, 3/8" in steel and 1/2" in concrete.