Internal walls

Also see:

6.3.13Damp-proof courses

DPCs shall be installed where required to prevent moisture entering the building.

Load-bearing partition walls built on foundations should have a DPC. Where partitions which could be affected by residual damp (e.g. timber or steel) are placed on concrete floors, a DPC should be provided directly below, even where there is a DPM beneath the slab.

DPCs should be:

  • at least the width of the wall or partition
  • linked with any adjoining DPM
  • continuous or lapped by a minimum of 100mm.

Where steps are necessary in the ground floor slab, a DPC should be:

  • incorporated as a continuous link between the upper and lower DPCs
  • protected from damage during construction.

Where steps are greater than 150mm, waterproofing should be provided in accordance with Chapter 5.4 ‘Waterproofing of basements and other below ground structures’.

Materials acceptable for DPCs include:

BitumenBS 6398
PolyethyleneBS 6515
Proprietary materialsTechnical Requirement R3