Removing paint from bathroom wall

What is the wall made of?

Frankly though what keeps tiles up is the tiles underneath and the grout between. The adhesive is to stop the whole thing doing a 'jacobs ladder' so the actual force on the adhesive is almost zero once the thing is up...

I wouldnt bother to remove the paint unless its gloss and stops the tile cement setting quickly

Is the paint peeling? Is it easy to remove using scraper?

If the answer is "no" to both there is really no need to remove the paint.

If you really need to remove it then I understand isopropyl alcohol will assist in softening the paint, not something I have ever done. If the paint is old and hard then sanding is a possibility.

Gloss or emulsion? I would not worry unless it was really flaky emulsion an/or a wall obviously suffering from penetrating or rising damp.

If it is gloss, wash with Flash or sugar soap to remove grease, then maybe roughen with wire brush or coarse abrasive paper?

Use tile spacers of course to stop them slidng down before adhesive has set.

and one of very few good uses of waterproof PVA is to prime before tiling to ensure adhesion and to prevent ingress of water. TW

but with a bathroom this can cause failure. PVA is definitely not waterproof.

For the paint, scraping it with something scratchy works. You don't need it all off.

NT

I would be tempted to just wire brush to roughen it then tile. You could do just one tile give it a few days and see how easily it comes off just to test it.

Rent this, or something like it:

and use some dust extractor. Takes off the top mm or so, done.

You (most likely) won't need one with diamond bits, the hardened ninja stars will be enough.

Thomas Prufer

for removing paint from wood there are devices that are like power planers but the 'knives' rotate in the same plane as the device you have shown. The idea is to just scalp off the surface without creating too much dust.

Like this one