The tile installer is right.
Can you install tile over painted concrete floor.
All paint will need to be removed before you begin installing the tile.
Unfortunately the tile cannot be adhered directly to the painted surface.
Painted concrete can be made porous with sandblasting or other hard abrasive actions.
As long as the paint is down well and not flaking you can go over it with some preparation.
Once the concrete floor is paint free the tiling process is similar to most other floor tiling jobs.
Installing tile over painted concrete adds a few extra steps to your tiling job.
If you use a stripper to remove the paint be sure to flush it thoroughly to remove any residuals.
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.
However you should remember this one instruction no.
Ceramic tiles will not adhere to an enamel painted floor because the surface is too smooth.
Sheets of cement backing available from most do it yourself.
Paint used on concrete will not bond with the tile adhesive.
Tile cannot be attached directly to painted concrete as the thin set will not adhere well to the paint.
No big deal hack or grind the epoxy coated surface to form keys and tile over.
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.
You want water to readily absorb into it.
Sand or scuff it up well and wash to get.
But there is a solution to the problem.
While you can install tile directly on concrete problems erupt when the concrete cracks or shifts.