I'm about to start a bathroom job which has half the walls made from Plasterboard and half from Blockwork. All the walls are painted other than the one's around the existing shower which are tiled.

I will rip out the existing plasterboard (with tiles attached) around the shower and replace with new Hardieback.

However, what do I do about the remaining painted plasterboard and blockwork walls on the other side of the bathroom? What's the best way to remove the paint of these?

A heat burner or acid. Could you not prep the whole room with backer board or plasterboard ready for tiling afterwards?

Thanks for the prompt response akinsontiles!

Surely heat/acid will damage the plasterboard and skin coat underneath the paint?

The bathroom is only 2.5m2 of floor area, the last think that it needs is to be made even smaller .

Sorry I have re read you post now. If you score the painted plasterboard with a criss cross markings you should get a good enough key to adhere the tiles to and then prime it.

When I'm not sure I would check with the adhesive manufacturer you intend to use first as they all have technical departments that would offer advice.

I'd be a bit wary of using a ready mixed adhesive onto these painted surfaces still though as if the paint is Vinyl silk it can look and feel like the adhesive is holding and then the tiles will fall off later on. Which is not good if this is for a customer.

the cost of plasterboard is small,i would remove it and replace it will take longer to remove the paint than replacing the boards

If you score the plasterboard it weaken it.

So replace all the plasterboard with Hardiebacker?

How about the solid walls which have been plastered and painted? What's the best way to get down to the plaster there?

For the record, I will be using a Mapei powdered adhesive.

You may use such a blade Buy Grinding Cups - Cup Wheels with dust cover connected to industrial vacuum (extractor). Very fast and effective method. If you around London i can make it for you. I got all necessery tools

Originally Posted by EViS

So replace all the plasterboard with Hardiebacker?

How about the solid walls which have been plastered and painted? What's the best way to get down to the plaster there?

For the record, I will be using a Mapei powdered adhesive.

Or can the existing plasterboard be replaced with new plasterboard in non-wet areas (i.e. everywhere but the shower)? Or may this not take the weight of the tiles (floor to ceiling)?

One way is to buy the cheapest wettest ready mixed and skim the walls, scrape this off while still easy to do and it should pull the paint off with it, assuming the paint is emulsion.

you could try a steamer, just leave it switched on in the room with doors and windows closed for about 20 minutes and it should help it scrape off with a decent bladed scraper

Right, so no really easy solution then. Do many of you professionals tile over painted solid walls?

just key the painted surface with sandpaper. nothing too abrasive, if they have used bathroom/kitchen paint this can be a pain to remove or just prime it if the paint is not loose.

Originally Posted by EViS

Right, so no really easy solution then. Do many of you professionals tile over painted solid walls?

no professorial tilers dont tile over paint