UFH advice/help

[R66bby]

Hey guys, looking at putting UFH in our extension that we are hopefully getting built next year. The plans show block and beam, then insulation, then a 500g polythene protection layer, Then I’d put the UFH in followed by the liquid screen.
My question is regarding the clips piercing the polythene protection/vapour layer. Is my only option to use the egg Crate system?

[Muncher]

That's exactly how we did ours, no problems. The puncturing of the vapour membrane I don't think really matters, it's not as if any concrete really flows through it. doesn't need to be totally air/water tight as far as I'm aware.

[R66bby]

Could I not fit a second layer of vapour barrier?

[Muncher]

R66bby said:

Could I not fit a second layer of vapour barrier?

I wouldn’t recommend it as you will create voids around the pipes, you want the screed touching it all round.

[037]

Can’t see why you couldn’t put a layer of polythene under the insulation as you are laying in on a flat block and beam floor.