The key difference between a Damp Proof Membrane (DPM) and a Damp Proof Course (DPC) lies in their application and scale. A DPC is a smaller, localized barrier, while a DPM covers larger areas.
Damp Proof Course (DPC)
A DPC is a relatively thin barrier, typically incorporated into walls during construction. Its primary function is to prevent moisture rising from the ground through masonry walls. It acts as a horizontal barrier, stopping capillary action. Think of it as a waterproof strip built into the wall. It's commonly available in roll form for easy installation.
Damp Proof Membrane (DPM)
A DPM, on the other hand, is a broader, more extensive moisture barrier. It's usually a sheet of polythene designed to cover larger surface areas, such as floors or under concrete slabs. Its purpose is to prevent moisture from penetrating the substrate, protecting the structure above. The reference states that a DPM is wider than a DPC.
Comparing DPM and DPC: A Summary
| Feature | Damp Proof Course (DPC) | Damp Proof Membrane (DPM) |
|---|---|---|
| Application | Built into walls | Covers larger areas (floors, etc.) |
| Scale | Localized, smaller area | Wider, larger surface area |
| Material | Typically a tape or roll | Polythene sheet |
| Purpose | Prevents rising damp in walls | Prevents moisture penetration |
Example: A DPC would be found integrated within the brickwork of a house wall, while a DPM might be laid beneath a concrete floor to prevent ground dampness from affecting the structure above.
