Applying a Damp Proof Course (DPC) correctly is crucial to prevent rising damp in buildings. Here’s how it's typically done:
DPC Installation Process
The primary method involves laying the DPC material horizontally at the base of the walls. This is usually done between the foundation and the first course of bricks or blocks.
Steps for DPC Application:
- Prepare the Surface: Ensure the foundation and the top surface of the wall where the DPC will be placed are clean, level, and free of debris.
- Cut DPC to Size: Measure and cut the DPC material to the required length, ensuring it covers the full width of the wall and extends a few inches beyond the wall on each side for proper overlap during installation.
- Lay the DPC: Carefully position the DPC material horizontally on the mortar bed. If using a flexible DPC material, such as polyethylene, ensure that it is laid flat without any folds or creases.
- Positioning: As stated in the reference, the DPC should be installed at the base of the walls, usually between the foundation and the first course of bricks or blocks.
- Extension: It should also extend a few inches above the ground level to prevent water from entering the wall above the DPC. This is important for proper protection.
- Overlap: If multiple sections are needed to cover a long wall, overlap the DPC material adequately (at least 100mm) to ensure continuous protection against moisture.
- Mortar Bed: Apply a fresh mortar bed on top of the laid DPC, ensuring even coverage so that the next layer of bricks or blocks sits firmly and level.
- Continue Wall Construction: Proceed with laying the next course of bricks or blocks, ensuring that they make full contact with the DPC.
Practical Insights
- Material Choice: The choice of DPC material (e.g., slate, bitumen felt, plastic) often depends on the building's design and the local climate conditions.
- Professional Help: If you are unsure about applying DPC yourself, it is recommended to consult with a professional builder.
- Correct Height: It is very important for the DPC to be installed at least 150mm (6 inches) above ground level and higher if there is a sloping ground level.
- Damaged DPC: Any damaged or poorly applied sections should be replaced to avoid potential damp problems.
- External Level: Ensure that the external ground level isn’t higher than the DPC. If it is, it could create a “bridge” for water to enter the wall above the DPC.
| Step | Description |
|---|---|
| 1 | Prepare the surface, ensuring it is clean and level. |
| 2 | Cut the DPC material to the required length and ensure proper overlap during installation. |
| 3 | Lay the DPC material horizontally, between the foundation and the first course of bricks or blocks. |
| 4 | Ensure the DPC extends a few inches above ground level for protection. |
| 5 | Apply a fresh mortar bed on top of the laid DPC. |
| 6 | Continue building the wall. |
By following these guidelines and paying careful attention to detail, you can effectively install a DPC and protect your building from rising damp.
