ShelterFoam is a high-performance insulation consisting of a superior closed-cell, lightweight and resilient expanded polystyrene (EPS). ShelterFoam meets or exceeds the requirements of ASTM D6817, Standard Specification for Rigid Cellular Polystyrene Geofoam. ShelterFoam is a high performance and high density product with a long-term stable R-Value, excellent dimensional stability, compressive strength and water resistant properties.