Rising Damp describes the gradual upward movement of water in the lower sections of a building’s walls by the process of capillary action: where a liquid travels upwards, against gravity, in a narrow tube. This is the result of complex inter-molecular attractive forces between the liquid and its surrounding solid surface, much like when water Rises upwards between the hairs of a paintbrush.
Observations of the phenomenon have been recorded since Ancient Roman times.
Rising Damp can damage the walls of a building, weakening the structure and causing damage to plastering. It also creates a habitable environment for fungi that cause wet rot.
Some form of damp-proof course (DPC) is required to remedy the problem.