Damp proof membranes (DPMs) are impermeable barriers used in building construction to prevent moisture — mainly from the ground — from rising into floors, walls, or other parts of a structure through capillary action (the natural wicking of water through porous materials like concrete or masonry). They create a waterproof layer that stops liquid water and damp from causing issues such as rising damp, mould, rot, efflorescence (salt deposits), or damage to floor finishes and internal decorations.
