Water underfloor heating, ceramic tiles - TilersForums.com

[barryrobins]

Hi - can anyone offer any advice. We have water u/f heating throughout house and had upstairs bathroom made into wetroom. Chipboard flooring, then dietra matting, then tiles. 6 months later, tiles cracking across floor. Have now been told that dietra matting not recommended for any u/f water heating and that even if we replace chipboard flooring with plywood, then this still may not work. All to do with joists not having "noggings" as a result of u/f heating pipes.

Don't know what to do now - cusion floor seems only alternative but this would obviously be above level of the shower flooring (which incidentially hasn't shown any signs of movement)
and completely ruin the look of the bathroom.

Any advice welcome!

 

[nybor62]

dont know who told you that ditra aint suitable but there wrong, your prob is the chip board

floor should have been strengthened and chip board over layed with cement boards imo

poor prep work imo

 

[Max@ableskills]

Hi - can anyone offer any advice. We have water u/f heating throughout house and had upstairs bathroom made into wetroom. Chipboard flooring, then dietra matting, then tiles. 6 months later, tiles cracking across floor. Have now been told that dietra matting not recommended for any u/f water heating and that even if we replace chipboard flooring with plywood, then this still may not work. All to do with joists not having "noggings" as a result of u/f heating pipes.

Don't know what to do now - cusion floor seems only alternative but this would obviously be above level of the shower flooring (which incidentially hasn't shown any signs of movement)
and completely ruin the look of the bathroom.

Any advice welcome!

Hi and welcome to the forum. It sounds like your floor maybe suffering from deflection issues. Basically from what you have said the floor was not strong enough because it did not have enough noggins.

I take it the floor was taken up, underfloor heating installed, chipboard put back down, then ditra, then tile.

If so when the floor was up more noggins needed to be installed.

No easy solution to this i am afraid

 

[Time's Ran Out]

:welcome:Who did the wetroom?

 

[Scott]

Its all defection

Edit: Deflection! although the tiles are defecting from a deflecting floor!

 

[The Legend; Phil Hobson RIP]

As above chipboard not suitable for tiling, Ditra mat is ideal for ufh. Providing the floor has been prepared correctly

 

[barryrobins]

Thanks for comments so far. In fact Schluter told me yesterday the matting is unsuitable for WATER underfloor heating but largely the problem is the unstable flooring. We are thinking of replacing chipboard with ply but really concerned that we'll just have the same problem in six months time. Is it possible to put more noggins in the joists? Sorry to be so uninformed about this - the builder who renovated the house put in the flooring and we employed a tiler to lay the matting and tiles. Its our opinion that assuming we know nothing about tiling, he should have advised us against laying tiles on chipboard over flooring that is unstable.

 

[barryrobins]

Re: Water underfloor heating, ceramic tiles

Thanks for comments so far. In fact Schluter told me yesterday the matting is unsuitable for WATER underfloor heating but largely the problem is the unstable flooring. We are thinking of replacing chipboard with ply but really concerned that we'll just have the same problem in six months time. Is it possible to put more noggins in the joists? Sorry to be so uninformed about this - the builder who renovated the house put in the flooring and we employed a tiler to lay the matting and tiles. Its our opinion that assuming we know nothing about tiling, he should have advised us against laying tiles on chipboard over flooring that is unstable​

 

[Ajax123]

Schluter sell Ditra Matting specifically for warm water underfloor heating systems so how on earth can they be saying it is not suitable. Either you are mis interpretting their comments or you are not telling us something about your floor.

Did you tell the builder that the floor was to be used as a wet room and to be tiled. Perhaps he has some questions to answer

I can't see much option here but to remove the floor down to the joists and replacing it with more suitable materials. Whilst I agree that deflection is likely to be the primary cause there are other things with this floor which could contribute e.g. chip board swelling due to water ingress, excessive thermal expansion due to high temperatures are 2 which spring to mind.

I cannot see any reason why Noggins can't be placed between the joists due to underfloor heating pipes. IN fact these would give you something to rest the pipes and assuming you have used them the diffuser plates on.

 

[barryrobins]

Thanks for your advice. We obviously need to discuss with builder and tiler but I promise you, Schluter did tell me yesterday that the matting is not recommended - or at least the chap who spoke to me when I asked for the technical department did - and of course the unstable floor adds to the problem. Just a headache but many thanks for taking time to reply.

 

[barryrobins]

PS - they said matting is ok with their u'f water heating but we didn't use theirs.....!

 

[Ajax123]

PS - they said matting is ok with their u'f water heating but we didn't use theirs.....!

That is a complete cop out on their behalf. Either it is suitable or it is not suitable. There is no difference technically between their wet system and any other wet system in terms of what it does to the floor. That aside I think it is beyond dispute at least as far as the forums are concerned that Ditra Matting is suitable for use with underfloor heating.

That said I don't think that this would have been the route cause of the problem anyway. As previously posted in terms of resolution I don't think you have much choice other than to remove what is there and replace it with more suitable floor build up.

I guess it is possible to just take up the tiles and use a mechanism on top of the chip board to help reduce deflection such as Lewis decking or something like that but that would affect the overall depth and weight of the floor so would need careful design consideration.

easiest and quickest thing for me would be take up the tiles and the chipboard, Lift the UFH pipes if necessary, put in additional noggins as required and then start again. May be the builder should be dealing with this?

 

[Derry]

Hello and welcome to the forums

 

[DHTiling]

Hello and welcome..

 

[White Room]

Hi and welcome​