Wood Structural Panel R-values

Oriented Strand Board (OSB)

The thermal resistance, or R-value (in ft2 - hr - °F / BTU), of OSB panels is listed below. Thicker panels have more insulating value; therefore R-values increase with increasing panel thickness. These values are listed in Table 2 of the Structural Board Association's "OSB in Wood Frame Construction," (U.S. Edition 1996/97).

OSB Thickness (inch) R-value
3/8 0.45
7/16 0.51
1/2 0.62
5/8 0.74
3/4 0.91

Plywood

The thermal resistance, or R-value (in ft2 - hr - °F / BTU), of plywood panels is listed below. Thicker panels have more insulating value; therefore R-values increase with increasing panel thickness. These values are listed in Chapter 25, Table 4 of the 2001 ASHRAE Handbook published by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE).

Plywood Thickness (inch) R-value
1/4 0.31
3/8 0.47
15/32 0.59
1/2 0.62
19/32 0.74
5/8 0.78
23/32 0.90
3/4 0.94
7/8 1.09
1 1.25
1-1/8 1.41