It is possible to tile over old tiles, however; it isn’t the best option. Eventually, the adhesive and grout in the old tiles will loosen, drummy, and lift, which in turn, will affect the new tiles. If the existing tiles are already showing signs of such problems, then removing them is the best option.
Of course, tiling over tiles also means the floor or walls will have at least 12mm-15mm added to them, which can cause other issues.
Moreover, tiling over bathroom floor tiles can cover any hidden waterproofing issues that, in years to come, could result in the entire floor, new and old tiles, being removed to repair the waterproofing.
If you’d still like to try your hand at tiling, please refer to our tiling guides: