Why is my adhesive dry and crumbling

[gaz42x]

I got 100 square metres of tiles laid 18months ago. after 7 months i noticed tiles starting to loosen. now approx 50% have loosened. i lifted a tile last week and the adhesive is dry and crumbling. No real adhesion to floor or tile. Tiles are laid on a concrete floor with no underfloor heating. Floor is there since 1971 and has been tiled twice with no problems. Floor was primed before tiling and tiler has about 40 years experience in residential and commercial tiling. Everything is pointing to a problem with the adhesive. adhesive used was weber. I now need to determine how to procede with this as i will have to rip out the whole bottom floor of the house with built in kitchen,utility,pantry,tv units, bookcases , bootrooms etc.. Estimate is between €15-€25k... has anyone have anything like this happen and if so how did you fare out ?????

 

[Dave]

Hi and welcome. Which weber adhesive was used and what tiles were laid. ?

 

[gaz42x]

Hi and welcome. Which weber adhesive was used and what tiles were laid. ?

Weberset rapid plus and tiles are porcel;ain

 

[Dave]

Weberset rapid plus and tiles are porcel;ain

Morning, can you post pics if possible of the adhesive and the tile back