Damp proofing in construction is a type of waterproofing applied to building foundation walls to prevent moisture from passing through the walls into interior spaces. A damp-proof course (often abbreviated to DPC) is a horizontal barrier in a wall designed to resist moisture rising through the structure by capillary action – a phenomenon known as rising damp. A damp-proof membrane (DPM) performs a similar function for a solid floor. In simpler words, DPC is used to stop dampness in buildings. To avoid water from reaching to walls, we lay DPC layer at plinth level (the joint level of walls and foundations).
Building standards in many countries require most new buildings to incorporate a DPC/DPM at the time of construction. This may consist of a thin strip of plastic, a course of engineering brick or slate, or a layer of bitumen.