A damp-proof course is a barrier, usually formed by a membrane built into the walls of a property, typically 150 mm above ground level, to prevent damp rising through the walls. Historically, damp-proof courses may have been formed using bitumen, slates & lead.

A damp proof course is installed in new constructions. Installation should be carried out according to the code of practice CP102:1973 and following normal DPC good practice procedures as set out in BS: 5628.