Many architects, structural engineers, and industrial contractors know, there is more than one grade of geofoam. Know what you’re getting when you are ordering geofoam; it should be marked and validated by the provider lest a catastrophe occur. There are numerous densities and expanded vs extruded types as well.
The steady rise in the use of Geofoam is not only in North America but all across the globe. The original use began in Norway in the early 1970s. The U.S. market first experienced it in 1989 (I guess we were slow adopters. Geofoam is in use in Canada, much of Europe, India, and throughout Asia.
Case in point: between 1985 and 1987, Japan used over 1,300,000 m3 (46,000,000 cu ft) of geofoam in 2,000 projects. (Source: Wikipedia)
When an unmarked block of geofoam gets delivered to a construction site for the underground utility stabilization from vertical pressures placed on pipes, there should be serious concerns. So much so that when two radically different densities of geofoam are placed side-by-side, no one could visually identify which was which. Seeing is one thing – touching them won’t provide any clues either, as the densities of geofoam are identical visually and in hand-feel, so much so that even industry experts often cannot tell them apart.
Just as critical an error would be if the wrong density of EPS foam were used to prevent landslides like the one pictured above. There are a right weight and a wrong weight for every purpose; it is crucial to ensure you are getting the geofoam product for which the intended project and outcome.
Using sub-standard geofoam for construction engineering might end up with significant failure and catastrophe could be imminent. Because of the different densities, structural engineers must verify the specific grade of geofoam needed when they are detailing their materials list.