First of all DPC is a barrier through the structure designed to prevent moisture rising. Consequently a capillary action such as through a phenomenon known as rising damp. Furthermore DPC or damp-proof course keeps moisture out of a building. Where vapor barriers keep interior moisture from getting into walls. Approved document C requires that, to prevent rising damp, a damp-proof course should be: Continuous with any damp-proof membrane in the floor. At least 150 mm above the level of the adjoining ground if it is in an external wall.