EPS geofoam can be easily cut and shaped on a project site, which further reduces jobsite challenges. EPS geofoam is available in numerous material types that can be chosen by the designer for a specific application. Its service life is comparable to other construction materials and it will retain its physical properties under engineered conditions of use.

There are numerous manufacturers and suppliers of EPS geofoam in North America. Expanded polystyrene is created in a two-stage, molded bead process. EPS geofoam is produced in blocks that can be cut into various shapes and sizes - and a range of compressive resistances - to suit specific project needs. As an engineered product, it can be produced to obtain the required compressive resistance. EPS geofoam density, only about 1% that of soil and rock, is controlled during the manufacturing process, making it a superior, ultra-lightweight fill material that significantly reduces the stress on underlying subgrades. The lighter load can reduce settlements and can improve stability against bearing and slope failures.

ASTM International provides a specification for the minimum properties of EPS geofoam. The relevant ASTM specification for EPS geofoam is ASTM D6817 Standard Specification for Rigid Cellular Polystyrene Geofoam. Other ASTM standards are D7180 Standard Guide for the Use of EPS Geofoam in Geotechnical Projects and D7557 Standard Practice for Sampling of EPS Geofoam Specimens. Thorough knowledge and understanding of the standard being used on a EPS geofoam project is essential.

ASTM D6817 Physical Property Requirements of EPS Geofoam
Density, min.
kg/m3(lb/ft3)
11.2 (0.70) 14.4 (0.90) 18.4 (1.15) 21.6 (1.35) 28.8 (1.80) 38.4 (2.40) 45.7 (2.85)
Compressive Resistance, min.,
kPa (psi) at 1%
15 (2.2) 25 (3.6) 40 (5.8) 50 (7.3) 75 (10.9) 103 (15.0) 128 (18.6)
Compressive Resistance, min.,
kPa (psi) at 5%
35 (5.1) 55 (8.0) 90 (13.1) 115 (16.7) 170 (24.7) 241 (35.0) 300 (43.5)
Compressive Resistance, min.,
kPa (psi) at 10%
40 (5.8) 70 (10.2) 110 (16.0) 135 (19.6) 200 (29.0) 276 (40.0) 345 (50.0)
Flexural Strength, min.,
kPa (psi)
69 (10.0) 172 (25.0) 207 (30.0) 240 (35.0) 345 (50.0) 414 (60.0) 517 (75.0)
Oxygen, min.,
volume %
24.0 24.0 24.0 24.0 24.0 24.0 24.0