An inverted roof is a roof in which the order of layers of thermal insulation and waterproofing has been changed. It is characterized by the fact that the sealing layer is laid directly on the structure, and a HOCH XPS extruded polystyrene board is perfectly suited for the thermal insulation layer made of water-resistant material. The geotextile then forms a moisture and water vapour permeable layer that protects against pollution, and the gravel or greenery layer forms a pressure layer. Reversing the layers in such a system makes the waterproofing protected by the remaining layers against weather conditions and mechanical damage.

HOCH XPS extruded polystyrene panels are ideal as insulation material for an inverted roof, protecting against changing weather conditions and mechanical loads that threaten the sealing layer.