Getting your damp proof course (DPC) right first time is critical in preventing rising damp in your property.

If you don’t install it correctly you could end up having to put things right at a later date leading to major disruption and unnecessary costs.

So why not take a look at these 8 handy hints for installing horizontal damp proof course put together by our technical experts.

8 handy hints for installing horizontal damp proof course

  1. Turn up the damp proof membrane (DPM) at slab edge. Ensure the DPM laps under the DPC for the full thickness of the inner leaf to form a continuous barrier (including under door sills).
  2. Lay the DPC on a smooth bed of fresh mortar in one continuous length. It should span the full width of the leaf including any finishes e.g. external render.
  3. Provide at least a 100mm overlap at any joint or angle.
  4. The DPC must not obstruct the cavity.
  5. Ensure the external edge of the DPC is visible and not bridged by mortar when completing pointing of the mortar joint.
  6. External render must not bridge the DPC.
  7. Ensure the lean mix cavity fill material is at least 225mm below the DPC level.
  8. Do not pierce the DPC with any services or fixings.


Check out our spot the defect article on damp proof course to see what not to do when installing DPC.

Please Note: Every care was taken to ensure the information in this article was correct at the time of publication. Any written guidance provided does not replace the reader’s professional judgement and any construction project should comply with the relevant Building Regulations or applicable technical standards. However, for the most up to date LABC Warranty technical guidance please refer to your Risk Management Surveyor and the latest version of the LABC Warranty technical manual.

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