“Damp-proofing” is used to describe the process of preventing moisture ingress to buildings due to Rising, Lateral and Penetrating Damp.
Rising Damp can occur in buildings due to either:
- The absence of a Damp Proof Course (dpc)
- The failure of a Dpc
- The “bridging” of a Dpc
Each one of these problems requires a specific type of treatment. There is no one miracle cure. It is absolutely essential that the root cause of this damp is properly identified so that the correct treatment can be applied.
Lateral Damp in a building occurs when ground level outside the building is higher than internal floor level and/or the level of the dpc. Typical examples of lateral damp are found in basements and cellars, flower boxes, raised pavements and split levels within buildings. This type of damp is preferably treated on the external/positive side of walls but where this cannot be done internal surfaces may be protected with a system called “tanking” involving the application of a waterproof surface on the walls.
Penetrating Damp occurs when the external “skin” of a building is unable to prevent rain water from penetrating the walls of the building. This is unusual in properties where external walls are plastered, except where cracks occur, but is more common in facebrick properties. Brickwork may be more porous than normal or mortar between the bricks may allow moisture ingress. In these cases the application of a water repellent to the exterior surface will usually prevent any further moisture ingress.