Hi all, hope someone can help out there. What is the correct order for relaying floor for underfloor heating Been told 50 mm sand, then concrete then celotex, then DPM, then 50mm cement mix
Can anyone give correct order and strength of mixes Thanks all out there.
From teh top at leasst 50mm SCREED - dry mix to prevent slumping, about
5:1 sand:cement. Maybe 4:1. With your pipes in it. I'd make that thicker if you can, to prevent hitting the pipes when youy screw e.g. toilets down...underneath, if you have space. 100mm of polystyrene may be cheaper than the celotex. I laid DPM under the poly, but over it is as good really.
Under that its really just down to a firm base for the insulation I didn't bother with sand. If your underlying floor is really rough, maybe about 6:1 sand and cement just tamped down level. I do not like the idea of pure sand. I'd probably lay the inuslation on a wet sand/cement bed myself. It floats anyway, so you acn almost have a wet puddle of sand and cement and flop teh poly on it and let it all set.
Underneath that its down to what the BCO and the structural people think is necessary for stability. in my case it was a raised block and beam floor. Nasty wet clay underneath you see.
So whatever it takes to get the strength up.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.