Geofoam is a rigid EPS foam that can be used for exterior applications such as lightweight fill, compressible inclusions, thermal insulation, and drainage. It is 100 times lighter than most soil and provides superior structural properties in many applications.
You should purchase geofoam manufactured near your project to minimize shipping and storage costs.
Geofoam is made by fusing expanded polystryrene (EPS) beads together in a block form to a specific density, achieving an objective compression strength.