Slab Rigid Foam Insulation Gravel or Sand ?

Im doing a slab on grade with: 2″ foam insulation + 15mil vapor barrier and wire mash.  For the base my excavation guy put compact sand but I been reading… Im doing a slab on grade with: 2″ foam insulation + 15mil vapor barrier and wire mash.  For the base my excavation guy put compact sand but I been reading…Read MoreGreenBuildingAdvisor