Twenty odd years ago I tiled my garage floor with self-adhesive vinyl floor tiles after using floor leveller. The job was a success but some have been damaged, so I want to re-tile. A couple of years ago I did the same in my shed but this was a disaster, the leveller turned powdery and the tiles came away. I do not want to repeat this in the garage so I thought I could tile over the existing vinyl tiles with new self-adhesive vinyl tiles. I thought this would be an ideal base but it does say on the box not to tile on tiles (but not what sort of tiles). However I did experiment sticking parts of tiles on tiles and it wasn’t all that successful. Anyone done this or can offer advice? Thanks.