Lapping rpm to dpc

Discussion in 'Builders' Talk' started by Coppers, Dec 7, 2018.

  1. Coppers

    Coppers New Member

    Hi Everyone,

    My builder has disappeared and I need some advice. He has built and extension up to dpc and one layer of block on top of the dpc. I need some advice about laying the concrete base. Currently the hardcore has been whackered down so it's ready for sand then dpm, insulation and concrete. I would have expected the dpm to extend up over the inner skin block at dpc level and the dpc to go on top, but as the builder has put a layer of block on top of the dpc already I can't do this. Do I just run the dpm up to the dpc (which protrudes on the inside of the block) and then seal the dpc to the dpm? If so does the dpm go under the dpc? Does it matter? And what do I seal them together with?

    Many thanks
  2. jonathanc

    jonathanc Active Member

    Talk to your building control officer but i’d Run the dpm up the walls 100mm above the dpc
  3. Isitreally

    Isitreally Well-Known Member

    The old way was to just run it up the wall above DPC and once the screed was laid cut it off level with the floor.

    These days though they BCO likes it to be dressed into the DPC this can be awkward using the 1500 grade DPM in the corners.

    As above ask you BCO what is acceptable bearing in mind how you stand at the mo in terms of build.
    KIAB likes this.
  4. Coppers

    Coppers New Member

    Thanks for the responses it is much appreciated. I suppose my other option is to remove the extra layer of block and take the dpm over the block as I think it should be in the first place.

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