I'm putting in a new garage floor 4" thick concrete with 2" foam insulation
underneath. The foam supplier wants to know the compressive load on the
foam to recommend what grade foam to use. The foam seems to be able to
support 30psi at a minimum, does anyone know what load is typical under the
slab? It is for a residential garage and I'm going to park a full size
pickup on top. The base underneath is compressed gravel. My calculations
come out to about 1.5 psi (given the building code spec of 125 psf for a
light truck and the weight of 95 Lbs cu ft concrete).