We have out dated mosaic tiles in out entryway, a look we would like to change. The problem is that these above ground level tile are set in two inches of cement. I have talked to different contractor that have given me conflicting information. One stated that we need to remove the exiting tile was concrete base, an option that is cost prohibitive. The second stated that we only need to smooth the surface with thin set and then lay the new tile and the third stated that the current surface, which after 40 years has no cracks or bad tile, should be covered with an elastomeric anti-fracture membrane with the tiles laid over the membrane. Is there an affordable and reasonably safe way to take on this project?
Assuming you will accept an increase in floor height of at least 15mm I do not see any reason why the new tiles should not be bedded on a cementious based latex adhesive. Perhaps your contractors know of a problem and not told you.