DPM on thresholds can I use bitumen

[Chanmenie]

When I built the foundations for the ICF blocks I lapped the DPM over the foundation walls, I’m now fitting the doors so will have some exposed DPM, which will need to be covered by the flooring,  I was planning on applying a levelling / latex compound about 4-5mm think, is this viable over the polythene DPM and the 30mm PIR upstand or is it likely to just crack.

Could I remove the poly DPM and use a Bitumen paint on DPM which I assume would give a much better key for the latex.

[saveasteading]

1 hour ago, Chanmenie said:

likely to just crack.

Could I remove the poly DPM and use a Bitumen paint on DPM which I assume would give a much better key for the latex

yes.

you mean 'as dpm'?  yes. 2 coats.   

Imagine yourself as a drop of water below the dpm/ bitumen. Is there a way through by suction  or pressure or gravity or as vapour? If there isn't , then any solution is a solution.

[Chanmenie]

2 hours ago, saveasteading said:

yes.

you mean 'as dpm'?  yes. 2 coats.   

Imagine yourself as a drop of water below the dpm/ bitumen. Is there a way through by suction  or pressure or gravity or as vapour? If there isn't , then any solution is a solution.

Yeah I have used bitumen DPM before many years ago, I could not think of any reason it would not work but just doubted myself.

Here’s the front door threshold, the DPM has been cut off as it was damaged by traffic and I had to grind the blocks down a little as they were a little high for the flush threshold required.

I’ll fit the door then raise the level of the porch with slabs or tiles so it’s flush both sides.

 

[saveasteading]

I usually ask for a first coat over mortar joints, cracks and edges, including under any dpc or dpm that overlaps. Then the whole area, and perhaps stippling it on rather than brushing so it goes into any small recesses. Then another coat. 

I've been 'lucky' with that dozens of times even though it's not 'by the book'

 

[Conor]

I used bituminous paint on all of our door thresholds and not one issue.

[Chanmenie]

Thanks guy’s