Before Christmas i tiled a bathroom floor in bisazza 10mmx10mmglass mosaics(paper fronted), black epoxy and theyve (WORD REMOVED) lifted.... The screed was anhydrite which iam aware of, so it was primed with benferprim, 2 coats and white flexi adhesive was used. Two other bathrooms and large kitchen floor have been tiled and nothing else has lifted. Only some grout cracking in the kitchen.

The property is a new build with approx 200m2 wet underfloor heating system. This had been on full blast soon after floor was tiled when we had the sub zero conditions in December. It was like working in the bahamas some days!
I personally think this is the main reason for the problem but im interested to see what other suggestions you guys may have to the cause of the problem??

So was this screed commissioned before you tiled it and how long had it been poured.?

i would say 99% it has something to do with the heating, it is supposed to be turned on gradually

How soon after the floor was tiled and grouted was the underfloor heating turned on? It shouldve been left for atleast 7 days before heating is turned on so it can fully cure in its own time. Ive been told its possible to get the laid adhesive tested to see why its failed, if it dried too quickly it can cause problems.

missyT

Could be any of the above? Screed is liable to cracking due to rapid differences in heat! Screed and / or Adhesive are both liable to pretty severe problems when force dried! I'd say a small section will have to be lifted to check how far the problems go??!?