Patent attributes
Below grade fluid containment structures, which may include a foam floor and a foam wall extending upward from the floor, the foam wall being formed from foam panels. A granular material is provided for reducing hydraulic soil pressure against an exterior face of the foam wall that would otherwise be exerted by the soil, if the soil were allowed to be positioned up against the foam, particularly the foam wall. The well-draining granular material may be gravel, crushed stone, or the like, which provides better drainage as compared to the surrounding soil material. The interior face of the foam is coated with an elastomeric abrasion resistant impact resistant polymeric coating that seals the below grade interior space defined between the floor and the wall in a seamless water-tight configuration.
