Are insulation boards needed?

[Niknak66]

Hello, I’m just having some work done in my house and decided to go with underfloor heating. Seen some other comments about using underfloor insulation boards. Asked my builders who said not needed as would raise the floor too much. Just wanted to check before work starts. Floor is concrete and i just had bakerlite tiles (asbestos) removed. The company left the bitumen and covered with some PVC (I think) coating to protect. Plan from builder is to screed, place UFH mats then screed again and tile. (My use of the word screed might mean other stuff) Is this correct? I’m removing all radiators downstairs so don’t want to find I’m freezing but concrete foundations are warm. Thanks in advance. Nicki

 

[Dave]

They are definitely needed , if not used then you will lose heat through the substrate and it’ll cost a fortune to run. And i also hope they haven’t used PVA.

 

[Bond]

Waste of time and money if you don’t insulate the concrete floor, First.

 

[Niknak66]

They are definitely needed , if not used then you will lose heat through the substrate and it’ll cost a fortune to run. And i also hope they haven’t used PVA.

Many thanks Dave, I’ll get that sorted. I think it was PVA. They said it would stop dust and fine as long as don’t screw thru it.
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Waste of time and money if you don’t insulate the concrete floor, First.

Thanks. Thought so but wanted to trust builder