Best way forward for walls in shower cubicle

[AndrewSchofield]

Hi all,

I'm planning to install a shower cubicle in an existing bathroom. Two of the walls are brick which are currently plastered and then tiled. The third wall forming the cubicle will be a new stud wall which I intend to face with tile-backer board. The existing tiles on the two brick walls are coming off, and then I intend to line-out the shower with wall panels - mermaid boards or something like that... so the only joins will be in the corner and where they meet the shower tray and these will be silicone.

What's the best thing to do with the brick walls? Should I take them back to the brick, and then dot & dab tile-backer boards on there too, or will the existing plaster be ok to attach the wall panels to (obvs. assuming the plaster is sound when the tiles come off...). With either option, should I tank the boards/plaster before attaching the wall panels?

 

[johnny2007]

If the plaster is sound you can use Bal apd solution 50÷50, tank the lot and tile when dry.
Regarding the stud wall, sound/thermal insulation between studs, then waterproof membrane stapled to studs shower side of course (any joint to overlap by 200mm), then aquapanels instead of plasterboard.
Once you have the aquapanelled wall, you can seal the joints with mesh tape and adhesive and tank it, ready for tiling.
To be honest, before this tanking business became popular, we would tile directly on aquapanel because it's a good surface to tile on and water resistant.
At the back of it you would have a waterproof membrane, so if water managed to pass the tiles, then the aquapanel, it would find the waterproof membrane and prevent wall rotting.
Also tiling on sound plaster was never a problem and many bathrooms and wet rooms are still standing after 30 odd years.

 

[johnny2007]

Sorry, duplicate post

 

[AndrewSchofield]

Thanks Johnny,

I looked online and there seems to be a split about whether aquaboard needs tanking or not, but if I'm tanking the plastered wall, makes sense to do the boards while I'm at it as you've said.

If the existing plaster on the walls isn't sound, what would your recommendation for those walls be?? I think it'll be ok, as I have taken tiles off in other parts of the bathroom and the plaster beneath has been good, so no reason to think it should be different in this corner, but just in case...

 

[johnny2007]

If plaster needs to come off, once on bare bricks, put aquapanel on them.