A damp-proof course (DPC) is a horizontal barrier built into a wall at a low level to stop groundwater rising up through the structure. It's one of the most important elements of any building's damp protection — and when it fails, the problems can be extensive.
What Is It Made Of?
Modern DPCs are typically a layer of plastic sheeting incorporated into the brickwork at or just above ground level. Older properties (pre-1960s) may have a DPC of slate, bitumen felt, lead, or even engineering bricks — all of which can deteriorate over time.
When Was It Required?
DPCs became a building regulation requirement in 1875, so any property built before that date is likely to have no DPC at all. Properties from 1875 to the mid-20th century may have an original DPC that has now failed.
Signs of a Failed DPC
- Damp patches and tide marks on the lower sections of internal walls
- Salt deposits (efflorescence) on brickwork or plaster
- Rotting skirting boards at floor level
- Damp smell in ground-floor rooms
Chemical DPC Injection
Where an original DPC has failed or is absent, a chemical DPC can be installed by drilling a series of holes along the mortar course and injecting specialist damp-proof cream. This is the most common modern treatment for rising damp.
Shadbolt Plastering installs chemical DPCs across South London and Surrey, backed by a written guarantee.
Need Help with This?
Shadbolt Plastering provides professional plastering and damp proofing across South London and Surrey. Call us for a free assessment.
Call 07803 461497