Minimize heat loss or gain with Owens Corning FOAMULAR? C-300 Extruded Polystyrene Rigid Insulation, designed for use on above-grade exterior walls and the interior of foundation walls. It has an outstanding thermal resistance of R-5 per inch, a strong compressive strength of 30 PSI, and exceptional moisture resistance. C-300 insulation is GREENGUARD Indoor Air Quality Certified? and contains 20% recycled material content. It?s lightweight and easy to cut and handle for quick installation and maximum job site efficiency. To further reduce heat loss and air and water infiltration, use C-300 insulation with shiplapped edges.