In construction, a water barrier is a structure or material that prevents water from penetrating where it is not wanted. This can range from a waterproof membrane under a foundation to a threshold at a door that keeps rainwater out. In civil engineering, the term refers to dikes and dams, but in the DIY context it is about small-scale water management.
Water barriers in construction projects
| Type | Application |
|---|---|
| DPC membrane (Damp Proof Course) | In the mortar joint of a wall to stop rising damp |
| Below-grade masonry | Water-resistant brickwork below ground level |
| Membrane under concrete slab | Prevents ground moisture from seeping into the concrete |
| Drip edge | Directs water away from window frames |
| Threshold (door sill) | Raised edge at a door opening that keeps water out |
| Sealant joint | Flexible seal between materials |
Related terms
- Below-grade masonry
- Drip edge
- Frost line
- Slope (drainage gradient)