Do I need to repoint?

[opps]

Cement board screwed over existing plaster will, theoretically, have a greater weight load than tiles over plaster. Equally, tiles over naked plasterboard have a greater weight load than tiles over skimmed plasterboard.

 

[Ivor Windybottom]

I agree. But I'd suggest your walls aren't suitable for dry-lining, you need wet plaster to bond it together.

Get it all off, get a couple of gallons of SBR sunk into it then get it properly plastered. You don't want a super-smooth surface for tiling. I don't know what best practice is these days, some might prefer cement render rather than plaster in a bathroom.

In my case/photos, the top skim came off with the old tiles in the shower area, and remained where it wasn't previously tiled. I tiled over the lot, managed to straddle the lip between the two halves without it being at all visible now. I used a liquid tanking kit in the shower area, over the rough plaster. It looked weird and drank the stuff up but worked really well. The bumps are good for the tiles to grip onto.

Don't use any pre-mix tile adhesive. Get slow setting powder mix. Powder is cement based, pre-mix can't be otherwise it would set in the tub, it's probably acrylic or similar but IMO inferior to cement. Cement will set underwater so has to be sold dry.

 

[yorksbuilder]

If you have the cement boards already, photo shows one that I did before where I stripped the plaster off and glued and fixed the cement board to the walls, no regrets about this, the finished tiling surface was solid and was flush with the other plastered parts of the wall and left perfect spacing for a tile trim at the edge of the tiles.

 

[collapse-sued-turkey]

I agree. But I'd suggest your walls aren't suitable for dry-lining, you need wet plaster to bond it together.

Get it all off, get a couple of gallons of SBR sunk into it then get it properly plastered. You don't want a super-smooth surface for tiling. I don't know what best practice is these days, some might prefer cement render rather than plaster in a bathroom.

In my case/photos, the top skim came off with the old tiles in the shower area, and remained where it wasn't previously tiled. I tiled over the lot, managed to straddle the lip between the two halves without it being at all visible now. I used a liquid tanking kit in the shower area, over the rough plaster. It looked weird and drank the stuff up but worked really well. The bumps are good for the tiles to grip onto.

Don't use any pre-mix tile adhesive. Get slow setting powder mix. Powder is cement based, pre-mix can't be otherwise it would set in the tub, it's probably acrylic or similar but IMO inferior to cement. Cement will set underwater so has to be sold dry.

Right makes sense. For now I'll definitely get all the plaster off and I'll see what I'm dealing with on the rest of it.

If you have the cement boards already, photo shows one that I did before where I stripped the plaster off and glued and fixed the cement board to the walls, no regrets about this, the finished tiling surface was solid and was flush with the other plastered parts of the wall and left perfect spacing for a tile trim at the edge of the tiles.

That looks good. I have to say though the state of your bricks and pointing looks much better than mine though