Underfloor Heating Causing Marks On Tiles

[On one]

You should have been able to seen some evidence of the (blue)dpm even if the excess dpm was cut off at a later date

 

[Chalker]

It will be pulling moisture up from the concrete floor.

Would have been better to have installed insulation boards on a concrete floor to prevent this happening and to stop heating 6 inch of concrete.

 

[White Room]

It will be pulling moisture up from the concrete floor.

Would have been better to have installed insulation boards on a concrete floor to prevent this happening and to stop heating 6 inch of concrete.

I thought matting had been laid, just read back and realised it had not...

 

[Just Rizzle]

did u do a moisture test on new floor befor laying BUILDERS have a habit of lying.
I never take a man for his word .
why if you've got two different areas didn't you decouple

if you take a job on its your responsibility to check these basic things.

 

[Lithofin BOB]

Maybe worth testing a cleaner, migrating contamination to the face, or heat an area to see if this will disperse .or poss return,

 

[MW Smith Ceramics]

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.

View attachment 80167

Hi mate,

The only thing I can think of that's causing this is moisture rising from the newly laid screed, did you put a hygrometer on the floor before fixing??.....what type of screed was it?....depth of screed??......how long had the screed been laid???

Looks like moisture

 

[MW Smith Ceramics]

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.

View attachment 80167

Did you use insulation boards??