Can you put new tile over old tile on a counter top?
You can tile over existing tiles if the wall is sturdy and none
of the old tiles is cracked or loose. If there are only a few loose
tiles, remove and clean them, then reinstall them with fresh
adhesive before retiling the wall. Epoxy tile adhesive bonds with
existing tiles, making it one of the best options for tiling over
an existing tiled wall.