The tile installer is right.
Can you install tile over painted concrete floor.
You want water to readily absorb into it.
The thinset will probably bond to the epoxy floor.
Sand or scuff it up well and wash to get.
Sheets of cement backing available from most do it yourself.
Before you lay any sort of tile whether it is stone ceramic or peel and stick vinyl you must prepare your concrete floor to ensure that the tiles will go down properly and stay where they re.
Even though nothing may happen nobody has a crystal ball and the track record of tile over painted floors is not great so he is basing his decision on historical data.
All paint will need to be removed before you begin installing the tile.
Once the concrete floor is paint free the tiling process is similar to most other floor tiling jobs.
While you can install tile directly on concrete problems erupt when the concrete cracks or shifts.
You need to prepare by removing the paint and scarifying the surface to open up the pores of the concrete.
As long as there are not structural cracks in the concrete floor you can install porcelain tile over it.
No big deal hack or grind the epoxy coated surface to form keys and tile over.
Tile cannot be attached directly to painted concrete as the thin set will not adhere well to the paint.
Installing tile over painted concrete adds a few extra steps to your tiling job.
Ceramic tiles will not adhere to an enamel painted floor because the surface is too smooth.
However you should remember this one instruction no.
Painted concrete can be made porous with sandblasting or other hard abrasive actions.
Paint used on concrete will not bond with the tile adhesive.
If you use a stripper to remove the paint be sure to flush it thoroughly to remove any residuals.