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What issues can occur with a failed damp-proof membrane DPM?

What issues can occur with a failed damp-proof membrane DPM?

Project type

  • Extension
  • Walls
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Damp-proof membranes (DPMs) are normally made from tough plastic sheets that will often require joining, lapping and taping if used to cover larger areas. These junctions can be potential weak points.

The sheets can also be damaged or torn before the concrete is poured on top of them.

Problems caused by damp-proof membrane failures include:

  • Wet concrete floors when groundwater rises through the porous concrete
  • Mould on the concrete and/or perimeter walls
  • Floors having to be replaced entirely if the source of the problem can’t be identified

Therefore it’s key that the DPM is laid and detailed carefully and links with the damp proof course in the walls.

Further information

How do I prevent excess moisture entering my new extension?