tile debonding from adhesive - advise needed

[matt_pepper]

Hi,

New member here in need of help.

About 6 months ago I had my kitchen tiled in 600 x 600 porcelain. The subfloor is mix of solid and timber suspended so I installed polypipe overlay heating system. These are essentially an 18mm concrete board that runs over the sub floor with piping for water ufh that are meant to compensate for backing board or ply overlay.

My problem is that some of the tiles are now lifting. I followed the rules and left the heating off for 21 days (prob more like 30+) and then brought the heating up v slow. My tiler insists he used a suitable flex adhesive (Ultra rapid set) but the adhesive appears to have de-bonded from the tile completely. When I lift the tiles off the tile bed, I see some cracks in the adhesive, but this still feels set to the sub floor but there is none on the back of the tile.

Has anyone seen similar or can advise on what the cause may be?

I initially thought deflection, but the tiles that have lifted are not in a high traffic area of the room.

Really would appreciate any advise from a pro.

Many thanks
Matt

 

[Dontiler]

hello and welcome
do you know which ady he used? did he back butter the tile? if you jump on the floor is the floor deflecting? where the tiles been stored before application? can you see how many mm of adhesive he used under the tiles? is it any chance you can take some photos of your floor and post it on here i think you would get you answer much faster this way

 

[DHTiling]

Hi, Some pics of what it under the tiles would help.. as in adhesive bed .?

 

[Brian the Tile]

dusty tile back ,adesive skinned over could be a few things as said photos would be good

 

[The Legend; Phil Hobson RIP]

Hi and:welcome: cracks in the adhesive sounds to me like the bed is to thick, as above pics would help.

 

[jonnyc]

i need to look my info up on this in morning.
i had a similar situation but so far so good.
need to look up what i specified after many confusing conversations with heating suppliers.
will revert am

 

[White Room]

Hi and welcome....

 

[matt_pepper]

Hi,


Thanks for all the replies... really appreciated


The ady he used was apparently Ultra ProRapid RS: Rapid Set Flexible Tile Adhesive.


The floor levels were not great so I think there is a pretty thick tile bed in places to compensate. I managed to get some of the tile bed up, and it measured about 12mm deep


I suspect there is some deflection on the timber floor but I am starting to notice cracked grout around tiles on the concrete sub floor too. Some of the areas where the tiles have lifted are not even traffic areas. It is strange because the tiles seem to be lifting or be loos on a corner or side where as the other side is still stable. Some have completely lifted all together and I have tried to show picture of remaining tile bed.


I have the tiler coming back out to take a look, but I wanted to have some ideas in advance...


many thanks
Matt