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?
I would think that option #2 would work as long as there are no cracks etc. in the old tile. Sounds like #1 and 3 just wanted to get more $ out of you.
#1 would be a pain to do but the end product would look better, #2 would be easier but there is a chance it may not look as great. I guess it is a decision of what you want to do because the difference between the two probably won't be a big deal.
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
The best way is to remove the old and start new. Having said that some considerations will be how long are you wanting to stay in this home? and what happens if the new floor is higher than before if you overlay the old tiles? You can sand the old tiles to brake the glaze with some coarse sanding paper or grinder. then float a thin layer of thin set to level the floor once its dry lay the new tiles thus increasing the thickness of the floor by at least the thickness of the new floor material and some thin set (all throw miner) but could be a problem matching against neighboring floor surfaces and interfering with doors. If the process is not done right you could have tiles popping up with weather changes if on a slap and in a cold climate. The removal of the old (not sure the area)should not be all that difficult with a SDS type tool and chisel for said tool which can be rented for a modest cost as a weekend rental. IE picked up Friday night or Saturday morning and returned Monday morning allowing ample time to complete the task.