Beaver Plastics Frost Cushion, 4x8x96
Beaver Plastics' Frost Cushion is manufactured from inert closed cell expanded polystyrene. It was designed specifically to be used under concrete grade beams to compensate for frost and moisture-induced swelling of underlying soils that might otherwise lift or fracture concrete foundations. Due to its closed cell structure it will not collapse due to water absorption and resists soil movement into spaces below the concrete. It is not biodegradable.