Hi everyone I’m after a bit of advice. I’ve just removed the floor tiles in our on suite. After we noticed that a couple had started lifting. This is the second time this has happened since we built our house about 12 years ago. The first time the happened about 6 years back the tiler recommended we use a decoupling mat which we did. This time after lifting the tiles the Anhydride screed has completely failed. And i noticed that after lifting the mat it seems to have retained some moisture. Could this be because the screed had not dried adequately when the tiles were first laid and the screed hasn’t cured properly ? Many thanks