Sauna landscapes have different areas (e.g. dry saunas, steam saunas, showers and other wet rooms), which are subject to different exposure. The waterproofing and installation systems must be matched with the prevailing conditions for each area. Due to high levels of exposure to steam in a steam sauna, the waterproofing and installation system must additionally have a vapour barrier function in order to protect moisture sensitive substrates, such as building boards made from polystyrene, from saturation from steam. This can only be fulfilled by reaction resin systems. In the more usual areas, where exposure to steam is not high, mineral-based waterproofing and installation systems may be used.