Damp proofing is defined as a material that resists the passage of water with no hydrostatic pressure and waterproof as a treatment that resists the passage of water under pressure. Generally, damp proofing keeps moisture out of a building where vapor barriers keep interior moisture from getting into walls. Moisture resistance is not necessarily absolute; it is usually defined by a specific test method, limits, and engineering tolerances.
Damp proofing is accomplished several ways including:
- A damp-proof course (DPC) is a barrier through the structure designed to prevent moisture rising by capillary action such as through a phenomenon known as rising damp. Rising damp is the effect of water rising from the ground into property. The damp proof course may be horizontal or vertical. A DPC layer is usually laid below all masonry walls, regardless if the wall is a load bearing wall or a partition wall.
- A damp-proof membrane (DPM) is a membrane material applied to prevent moisture transmission. A common example is polyethylene sheeting laid under a concrete slab to prevent the concrete from gaining moisture through capillary action. A DPM may be used for the DPC.
- Integral damp proofing in concrete involves adding materials to the concrete mix to make the concrete itself impermeable.
- Surface coating with thin water proof materials for resistance to non-pressurized moisture such as rain water or a coating of cement sprayed on such as shotcrete which can resist water under pressure.
- Cavity wall construction, such as rainscreen construction, is where the interior walls are separated from the exterior walls by a cavity.
- Pressure grouting cracks and joints in masonry materials.
Damp proofing paint is specifically formulated to protect against damp interior walls. This type of paint can also be used as a primer, prior to painting with a decorative finish paint. A quick reminder – damp proofing should NOT be used as an alternative to solving any underlying damp problems.
Polycell Damp Seal Paint has been specially formulated to seal patches of penetrating damp on interior walls and ceilings in just one coat, preventing them from showing through and spoiling decorations. Prevents damp from showing through and spoiling decoration.
So, does damp proof paint really work?
With the right technique and the right brand, yes, damp proof paint can really protect your home against damp. Just remember that ordinary paint will not treat damp or mould problems. It is also important to note that damp proof paint will not work as a substitute if your property is suffering from structural damage caused by damp.