Screeding and water feed pipe runs

[Elshanko]

Hi,

I'm laying PIR insulation boards on my slab in preparation to clip underfloor heating pipes to it. The problem I have is that I have had to cut the boards around my water feed pipes running across the room, so I have channels which I need to fill to prevent the screed cracking when it's laid on the UFH pipes. What should I use to fill these channels? Would sand work? I've blinded the PIR boards on the slab using sand.

 

[jeds]

Expanding foam. Let is cure and trim off flush.

 

[Elshanko]

Expanding foam. Let is cure and trim off flush.

Thanks John, I was hoping this would be the case as I assume the expanding foam has similar properties to the pir. My only worry is that an odour or taint might be transfered from the foam into the water feed - what do you think? I assume the foam wouldn't react with and deteriorate the water pipe (PVC)?

 

[jeds]

Wrap a bit of poly around the pipe first.

 

[Elshanko]

I just spoke with Polypipe and they said polyeurethane type foam is fine used with plastic water pipe, for future reference.