The polystyrene foam has a density of 2.75 lb/ft3 (0.5 kN/m3) with a 48 psi (331 kPa) compressive strength at 10% deformation. It is serviceable in temperatures up to 175°F (79° C).
The expanded polystyrene used to manufacture Schluter-KERDI-SHOWER products is treated with a flame retarding agent. The foam is self-extinguishing and achieves an HF-1 rating according to UL 94. Expanded polystyrene should not be exposed to hydrocarbons, esters, amines, and aldehydes. All will deteriorate foam. Schluter-KERDI-SHOWER-ST is designed to be used as a base in tiled shower receptors. Schluter-KERDI-SHOWER-SC is designed to be used as a base for tiled shower curbs and integrates with Schluter-KERDI-SHOWER-ST or conventional mortar applications. Schluter-KERDI-SHOWER-SB is designed to be used as a base for tiled shower benches and integrates with Schluter-KERDI-SHOWER-ST or conventional mortar applications. Schluter-KERDI-SHOWER-SR is designed to facilitate the construction of access ramps for tiled shower installations.