As the plasterers are nearly finished I need to finally figure out how to seal the walls to the floor. Cavity block walls, slab is down and we'll soon put the pir on it then dpm, then 50mm liquid screed with ufh. There's a dpc at the top of the slab level.

 

Options as I see it:

1. Page coat from bottom of plaster (which is at top of screed level) down to slab, as one course of block is exposed.

2. As 1. but also additional seal to slab, with either airtight paint or tape. (Straddles dpc)

3. Wait until screed is down then seal onto it. Would be with tape as need to straddle the 25mm PIR upstand.

4. Something else...

 

 

Im thinking I don't much fancy options 1 or 2, parge coating going to be a pain now plastering is done.

I used airtight paint.  But I would wait until you have screed down.

 

Not sure parge would be very successful, it wasn't when I did mine, hence using airtight paint.