Foamular® Thermapink® Extruded Polystyrene (XPS) Rigid Foam Insulation is made with Owens Corning's patented HydroVac process technology under strict quality control measures, which helps to make it highly resistant to moisture and permits the product to retain its high R-value year after year, even after exposure to moisture. Owens Corning Foamular® Thermapink® Extruded Polystyrene (XPS) Insulation is a closed cell, moisture-resistant rigid foam board specially designed for roofing applications.