Backerboards on wet ufh

[mike1979]

ok i went to look at a job wet ufh with flo screed on top all dried out etc the problem is in the dinning room they have laid a wooden floor and the tiles are to go around the primiter of the floor the into the kitchen through to the wetroom and basically they have lifted the former in the wetroom 6mm because they knew the wooden floor was going to be really thick so I suggest rather than trying to use leveller as it’s going to be an arse ache I suggested using a 4mm insulated backerboard and the customer said I was talking rubbish and a self leveller needed to be used as it would transmit the heat more than my backerboard any input would be great and if my board was a rubbish idea I shall hide in disgrace many thanks lads and good luck England tonight from a welsh lad

 

[Dumbo]

The key here is the word that you use , insulation . Your choice of board will prevent or limit the transfer of heat from the subfloor

 

[mike1979]

So you think by using the insulated backerboard it would prevent or limit heat ?? And I should self level it up 6mm

 

[Dumbo]

First part definitely as you usually use insulated backer board to prevent heat transfer from electric ufh to the substrate so as only to heat the tiles .
Levelling compound will give better heat transfer .

 

[mike1979]

That’s a good point and thinking about it I shall bow down to this one and agree fibre flex leveller it is

 

[Flintstone]

I agree with the customer here, why wouldn’t you level i? It’s made for the job!

 

[mike1979]

All points taken admit silly idea moment of brain madness we all have them get the Johnson 6x6 out loads of dots needed job done thanks for not insulting me too bad

 

[Alan Mearns]

The key here is the word that you use , insulation . Your choice of board will prevent or limit the transfer of heat from the subfloor

Hi I’m new to the forum and have a similar question. My builder is wanting to use hardiebacker board (12mm) (picture attached) on top on the laid water pipes. My concern is that unless they use a cement board specifically designed to be highly conductive, the Hardiebacker board will significantly limit heat transfer. Is this correct?

 

[Dumbo]

View attachment 101808
Hi I’m new to the forum and have a similar question. My builder is wanting to use hardiebacker board (12mm) (picture attached) on top on the laid water pipes. My concern is that unless they use a cement board specifically designed to be highly conductive, the Hardiebacker board will significantly limit heat transfer. Is this correct?

I know expert on this matter but maybe you should phone hardi and get them to integrate the u values of their board and also no more ply and Beava board . I do expect their values to be similar in a like for like thickness . Cement boards transfer heat to a degree whereas foam insulation boards are designed to insulate so therefor wi limit heat transfer . But I would say that the builder is doing the correct thing . But one question why are you not using a tiler their are regularly people on here saying something gone wrong when their builder has tiled something . After all would you ask a tiler to build a wall

 

[Alan Mearns]

Thanks for your reply. I will email hardiebacker and ask the question. I take your point regarding using a tiler. Reading this forum has highlighted how specialist this business is. Kicking myself.