Can I use spray polyurethane foam to insulate an existing home?
Spray polyurethane foam is used primarily to insulate new homes. This is because spray polyurethane foam must be applied to an open cavity. When spray polyurethane foam is injected into a closed wall cavity, the pressure of the expanding foam may damage the wall. Consider insulating an existing home with spray polyurethane foam when youre replacing the exterior siding or doing other major remodeling.
