The difference between “Damp Proofing” and “Waterproofing” can be defined by the material installed and its resistance to hydro-static pressure. A damp proofing system or damp proofing course resists the passage of moisture and water with no hydro-static pressure and waterproofing systems and materials resist the passage of water that is under pressure. Below grade damp proofing is a common practice in areas with lower water tables that still have the threat of moisture, particularly in residential basement construction. Damp proofing takes place to prevent moisture and water from entering the substrate and causing decay and to keep the interior of a structure reasonable dry and pleasant while avoiding interior mold and dry/wet rot problems.
While vapor barriers generally keep interior moisture from getting into walls, damp proofing keeps exterior moisture out of buildings. A damp-proof course is a barrier designed to prevent moisture from entering the structure through capillaries in concrete and masonry. A damp-proof course usually consists of some sort of membrane material applied to prevent moisture transmission. It can be applied horizontally or underneath foundation floors or directly to vertical walls that will be exposed to moisture.
Damp Proofing is a great solution to prevent musty basements in certain areas, but it is not a replacement for true waterproofing. In areas with higher water tables or higher-pressure water intrusion, damp proofing will not cut it and true waterproofing will have to be used. Damp Proofing is a great, economical, solution for many below grade structures, particularly in northern climates where the only issue is ground moisture and not serious water intrusion.
IWS Water Proof is a certified product for both damp proofing and waterproofing. It is an easy to apply product that forms a waterproofing membrane and will adhere to just about any surface including concrete and wood.