Can DPM form DPC?

[purplechap]

Is it sufficient to insert the DPM from the internal floor slab into the internal section of a cavity wall to form the DPC; or is a separate DPC strip required in addition to the DPM?

If so (i) WHY and (ii) does it matter if the DPM sits atop or beneath the DPC?

Thanks

 

[masona]

Is it sufficient to insert the DPM from the internal floor slab into the internal section of a cavity wall to form the DPC

No, because the DPC is made of heavy duty plastic which will take the total weight of the walls. You can slide the DPM under the DPC to the first cavity width of the wall. If the DPM is the same level as the DPC then you can use Visqueen jointing tape. It is impossible to lay mortar on top of DPM which will keep sliding off as with DPC it doesn't because it has a fine tread on it. DPM should be continuous with the DPC to the walls.

 

[purplechap]

Thank you very much for sharing your experience and knowledge masona. It all makes sense