What to do and why

[Gazzer]

It was timber joists with king span then moisture resistance tg 22mm floor boards he says he used 12mm ply screwed at 150mm gaps

Adhesives etc?

 

[TandS]

It was a powered cement based flexible adhesive could it be due to the floor being too hot or being turn on too soon

 

[Gazzer]

It could be shock from the under floor heating but at the moment its all guess work....we need to know products used and in what order etc....as much detail as possible.
Was the heating on while tiling ?

 

[TandS]

No it wasn't but it was turned on the next day as far as I'm aware

 

[Concrete guy]

Was the heating commissioned before the tiles were fitted?

 

[TandS]

What do you mean by commissioned sorry if that's a stupid question

 

[TandS]

Not sure please bear with me everyone I'm not total sure how to use the site computers ain't my thing sorry

 

[Gazzer]

Right It was turned on to soon so we can only point the finger towards that. I always say 2 weeks drying time before turning the heating on and only to increase the temp by 3 or 4 degrees per day.

 

[Concrete guy]

No it wasn't but it was turned on the next day as far as I'm aware

That's your problem. Should be left 28 days before it's switched on (or always used to be).

 

[Concrete guy]

What do you mean by commissioned sorry if that's a stupid question

switched on, run and tested far more important with water UFH but still prudent with electric as long as it's been screeded in.