Breathable membrane is typically used within an external wall, or roof construction, where the cladding may not be completely watertight, such as a tiled roof. The membrane is designed in a unique honeycomb structure, which allows is to be completely water resistant as well as air permeable. Breathable membrane will prevent any condensation or moisture build up, preventing the building from damp which can cause further problems such as, mould, mildew, corrosion, or decay. It does this by being able to vent and drain away any moisture to the outside.