Foam Sheathing

A ProWall worker packs EPS foam sheathing for use in residential and commercial construction.

The easiest way to increase the R-value in exterior walls is to protect them with insulated foam sheathing.

Some builders use 1/2-inch wood sheathing (R-0.6) or asphalt impregnated sheathing, usually called blackboard (R-1.3) to sheath the walls.

By using a 1/2-inch foam insulated sheathing (R-2 to R-3.5) in combination with wall cavity insulation, the total R-value of the exterior wall will be increased, contributing to greater energy efficiency. Sheathing thicker than 1/2 inch will yield even higher R-values.

Another advantage of insulated foam sheathing is that, when properly installed, it provides moisture control. It protects against condensation on the inside wall by keeping the interior of the wall warmer. Insulated foam sheathing has these additional advantages:

  • The continuous layer of insulation reduces thermal bridging through wood studs, saving energy and improving comfort. Thermal bridging occurs when there is a break in the continuity of the insulation layer, which results in heat loss.

  • It is easier to cut and install than heavier-weight sheathing products.

  • It usually costs less than plywood or oriented strand board (OSB).