Huge problem and sleepsless night ,opinions please

[One Day]

Sensible suggestions so far.
I've seen poor bonds on porcelain (while of on substrate) caused by tiles being stored outside in very cold temperatures.
Think the chilled tile doesn't form a good bond with the rapidset - not long enough for the reaction to warm the porcelain, whereas the substrate is warm and porous enough.
Just a suggestion....

 

[pdmbathrooms]

He layed the ply ,layed the heating mat then put slc over it as advised on the instructions , he is in the building trade so he wanted to do as much himself as he could , the thermal shock theory sounds the most plausible , the problem I now have is he reakons its my fault however I believe its all been prepped wrong .I made the mistake of presuming he knew what he was doing , I came in and saw a levelled floor and used products that are reliable , not sure how to approach it all

 

[Diamond Pool Finishers]

[video=youtube;v5wobrRYiiI]https://www.youtube.com/watch?v=v5wobrRYiiI[/video] And also remember that diffrent materials expand /contract at different rates !! witch causes problems in different layers applied to the substrate

 

[White Room]

Sensible suggestions so far.
I've seen poor bonds on porcelain (while of on substrate) caused by tiles being stored outside in very cold temperatures.
Think the chilled tile doesn't form a good bond with the rapidset - not long enough for the reaction to warm the porcelain, whereas the substrate is warm and porous enough.
Just a suggestion....

Again thats thermal shock due to the different temperatures, all tiles should be bought in for at least 24 hours to be climatized to the working areas.

 

[Diamond Pool Finishers]

And in response to TJ question you need to find -out the coefficient of every material in all the layers and make sure they are compatible like this or consult a set of pre-worked tables [video=youtube;5ud3kX9IVW0]https://www.youtube.com/watch?v=5ud3kX9IVW0[/video]

 

[Stef]

The 1st thing I notice is that the tiles haven't been back buttered,
Very little bond on back of tile.
Onto ply, even though it's been overboarded with ply I would still try & stick a backer board down.

 

[beanz]

How long before the underfloor heating was turned on? Lack of back buttering could also be a contender here...

 

[Rookery]

Just my opinion but I'd say:
1. Too much deflection in middle of floor.
2. Tiles not back skimmed.
3. UFH switched on too soon and not warmed & cooled gradually.
I wouldnt have tiled to ply either.

 

[radim]

two different materials expand in different way when heated (tile and adhesive) and this may lead to crack. So when tile debond from adhesive it is actually horizontal crack. IMO