The damp proof course (DPC) prevents rising damp in your property. It is really critical to get your
DPC right for the first time.
Incorrect installation of the DPC could end up leading major disruption and unnecessary cost of redoing it. Follow these 8 handy hints provided by our technical experts for installing horizontal DPC.
1. The inner leaf DPC must link with the up stand to the damp proof membrane, by a minimum
of 50mm and must be sealed to it. This is to ensure a continuous barrier against damp, this
includes where low-level cills are present (i.e., doorways).
2. Apply the DPC on a full even bed of fresh mortar in one continuous length and for the full
width of the leaf.
3. Provide at least a 100mm overlap at any joint or corners.
4. Ensure that the DPC does not obstruct the cavity.
5. Ensure the external edge of the DPC is visible and not bridged by mortar when completing
the pointing of the mortar joint.
6. Ensure that no external render bridges the DPC.
7. Ensure that the lean mix cavity fill material is at least 225mm below the lowest DPC.
8. Ensure that the DPC is a minimum 150mm above the external ground level.
If you are building on a sloping site, install a stepped DPC. Ensure that the DPC is stepped in the
masonry coursing so that it is never less than 150mm above the finished ground level as shown in
the diagram below:
The information in this article is correct at the time of publication. Any written guidance provided
does not replace the reader’s professional judgement and any construction (should comply with the
relevant Building Regulations or applicable technical standards). For up to date LABC Warranty
technical guidance, refer to the Risk Management Surveyor and the latest version of the LABC
Warranty technical manual.