Foamular® 150 Extruded Polystyrene XPS Rigid Foam Insulation is great for many residential and commercial construction applications such as wall furring, perimeter/foundation, cavity wall, pre-cast concrete, crawl spaces, sheathing and other applications. Owens Corning Foamular® 150 Extruded Polystyrene XPS Rigid Foam Insulation is a closed cell, moisture-resistant rigid foam board well suited to meet the need for a wide variety of building applications.