Underfloor Heating Causing Marks On Tiles

[yogi19]

Hi,

I recently laid underfloor warm up style matt heating. Half is an old floor taken back to concrete. And half was a new screed laid a few months prior (according to customer) The floor was primed with the primer that was issued with the heating. The floor was then covered in flexible latex once dried ceramic tiles were laid with flexible adhesive. So a few weeks after finishing the floor I receive a call from the customer saying something is wrong with the tiles. So I received the pics and the tiles have started to discolour. The discolouring had only started when he turnt his underfloor heating on which was a few weeks after being tiled. Has anyone experienced this or know of anyone who has. I also rang the company who provided the tiles they said that the tiles were suitable for underfloor heating. Her answer was that quick I was surprised she even knew what tile I was talking about. Any advice. Much appreciated.

 

[White Room]

Are the wires laid directly onto floor screed ?

 

[yogi19]

The matting was laid on top of a concrete screed that the builder had laid a few months earlier. As well as on the other side of the kitchen

 

[Tile Shop]

Is that a fairly recent extension? We have a similar issue in our conservatory, which the damp proofing ain't great. So rising damp maybe? Our porcelain tiles are fine but moisture easily comes through the grout in soggy weather conditions. But a ceramic would soak it up and show water marks.

Just a possible theory.

 

[White Room]

The fact that the builder done part of the job so you didn't have a visual of the screed....

 

[yogi19]

Yea I mean he did say the screed had been down 2-3 months before I tiled on it and he left the ufh off for another 3 weeks after tiling.....

 

[yogi19]

The marks have only come on he tile on the sie where he new screed is and not the old part of he kitchen. Which Did make me think that the screed wasn't set and moisture is still there. But surely I'm not he first person to have had this problem??

 

[On one]

No Damp Proof Membrane in the new part of the screed???

 

[yogi19]

Yea the builder definatley damp proofed it. So if they are water marks would they stay stained or dissappear over time......... I forgot to mention that the house has had no heating at all since the day the ufh went on.

 

[On one]

Damp proofed as in......???

 

[yogi19]

Dpc membrane. Are they not compulsory on building regs? ??

 

[On one]

Just checking
Possibly......DPM joints not lapped or taped correctly and moisture is wicking up

 

[yogi19]

I have no idea. That had already been done by the time I got there. I was told that as the moisture dries out then discolouring should go does that sound right?

 

[White Room]

I'd give a month before anything else to be honest with ufh running....see if it dries out.

 

[yogi19]

OK thanks. Appreciate it