Original tiles on wall the existing tile joints are in yellow.
Tile over tile in bathroom wall.
Grind them down with a grinder.
Lay a level on the old tile and mark any high spots.
You can tile over tiles with the right preparation but i would never do this the proper way is to strip right back to original wall finish.
New tiles on top of old tiles the new tile joints are highlighted in red.
Bjd building roofing say.
Learn the largest tile industry secret to remodel your bathroom for just 200 bucks and 1 days work.
Tile on tile or as i say it.
Always stagger your joints when putting new tiles onto old tiles what to do at the edges where double thickness of tiles show.
Don t worry if you do pull a bit of plaster when stripping the tiles as it s easy enough to replace.
Generally speaking thin set adhesive also known as thin set mortar is great for setting tiles in areas subject to moisture like bathrooms while mastic adhesive is best for drier spaces like.
Scrub the wall tiles with diluted degreasing cleaner and a nylon scrub brush.
If your old ceramic tile is worn or dated you can lay new tile right over the old and avoid the huge job of tearing out the old tile.
Mix degreasing cleaner with water in a bucket using a dilution recommended by the cleaner manufacturer.
And it lasts for 20 years.
Very easy diy that will save you hundreds of dollars not paying a contractor.