laying block work on top of DPM

14 Apr 2017
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United Kingdom
We built up to DPC with 100mm blocks, laid down the DPM, and had the concrete slab poured. I am now going to lay 100mm blocks on top of the DPM and need some guidance on how I should proceed.

1. Should I mortar underneath the DPM, or just above it ?
2. How thick does the mortar bed need to be when laying the blocks on top of it ?
3. How should I deal with the creases in the DPM ?
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Yep that's fine as long as you have enough distance from the ground to you DPM(in this case DPC as well).
Hm? The DPM protects the slab from water penetration, and covers block work below the slab too, and thereby acts as a DPC too? It's single block BTW.

You will find that is contrary to current thinking and practice.

You don't see rolls of 100mm polythene down at the merchants either. I wonder why?
use DPC it is designed to be used under high compressive loads, unlike polythene
The DPM is lapped under the DPC, which is laid on a 10mm solid bed.
Oh get off with yous.
DPC is polythene, the only difference is it has those little crosses on the back.
You're not building a massive multistory building there will be no difference in material properties.
If you're that pedantic put some DPC under the DPM.
Visqueen says both it's DPC and DPM are polyethylene.
So what's the difference?

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