[Closed] Tiling over existing bathroom tiles

If you take the old ones off you might find you’ll have to replaster the wall first. It’ll be a better job though.

Go with a shower wall system rather than tiling. One panel per wall so minimal joins. The better quality stuff looks good too. Ideally it'd go on a bare wall but no real issues with going over tiles (if you can live with yourself not doing a 'proper' job)

We’ve just had our bathroom done and they said they’d have to remove all the mosaic as they couldn’t guarantee it would hold securely with them weight of the new tiles on it as well.

As a tiler I’ll give you my thoughts on it...

Tiling over tile is fine IF they are securely fixed and on a sound substrate that can take the weight, which is the problem... you can’t guarantee the state of the wall behind, or the adhesion of the existing tiles.

2nd problem... Plasterboard is only rated to 35kg/m2 which includes anything attached to it, so skim and old tiles have to be subtracted from that. 10mm porcelain tile can easily weigh 25kg/m2.

Mosaics are normally a sod to remove however. If you are going to go over, clean them well with sugar soap and then use prime & grip before tiling.

Hmmm, the weight is a very good point.

On one hand it looks there is a plywood layer between the mosaic and the plasterboard wall, but on the other the existing tiles have been applied so unevenly that I’m not confident they would stay on.

I’ll be taking them off and starting again.

The bathroom in our new house has floor to ceiling* glass (coloured behind the top layer). The entire shower area is 3 massive pieces. I'm sure it's not a cheap option but it is so much easier to keep clean, there is hardly anywhere for mold to grow. A quick squidgy removes all the water (rather than leaving it in the grout on tiles). It also looks much better than the similar plastic based shower liners.

*Well picture rail but that's ceiling height for most houses.