... .Polystyrene xps board is high performance, reinforced insulation boards made of waterproof extruded polystyrene, each ... as a structural, in underfloor heating insulation, wet rooms, water pipes, ceilings and shower trays as a water ... XPS:Perimeter insulation, thermal insulation of flat roofs, floor insulation, exterior wall insulation, ceiling heat insulation, steep roof insulation, interior fitting ...