Questions about wall preparation

[Loldie]

Hi,

Apologies, this is quite a long question... I am currently renovating my bathroom and soon to embark on tiling the walls with ceramic metro tiles.

When removing the old tiles, some of the plaster / skim underneath came off in patches to reveal a mixture of bare concrete and flaking original paint.
I have removed as much of the loose paint and plaster as possible but am wary of removing the whole lot as I'm 95% sure its lead based with a glaze over the top, so don't want to disturb it too much. The surface of the wall now appears to be relatively stable.

There's approx 2mm height difference between the concrete and the remaining plaster.
I was advised by a tiling shop to apply a thin layer of primer mixed with tiling adhesive 24 hours before tile installation to fill the gaps and create a level surface.

I have also purchased a tilemaster tanking kit for waterproofing purposes...

So my question is...

a) is this a reasonable approach?
b) if so, which order should I do this in? (gap fill with primer/adhesive mixture, then tank? OR tank, then gap fill?

Any advice would be greatly appreciated

 

[Dave]

Hi,

Apologies, this is quite a long question... I am currently renovating my bathroom and soon to embark on tiling the walls with ceramic metro tiles.

When removing the old tiles, some of the plaster / skim underneath came off in patches to reveal a mixture of bare concrete and flaking original paint.
I have removed as much of the loose paint and plaster as possible but am wary of removing the whole lot as I'm 95% sure its lead based with a glaze over the top, so don't want to disturb it too much. The surface of the wall now appears to be relatively stable.

There's approx 2mm height difference between the concrete and the remaining plaster.
I was advised by a tiling shop to apply a thin layer of primer mixed with tiling adhesive 24 hours before tile installation to fill the gaps and create a level surface.

I have also purchased a tilemaster tanking kit for waterproofing purposes...

So my question is...

a) is this a reasonable approach?
b) if so, which order should I do this in? (gap fill with primer/adhesive mixture, then tank? OR tank, then gap fill?

Any advice would be greatly appreciated

Hi. Is it just one wall or all over ?

 

[Loldie]

Hi. Is it just one wall or all over ?

Hi Dave,

Thanks so much for responding.
It's only half a wall (about 1.3m wide by 1.8m high) - I have attached a photo.
The rest of the wall is covered in stable waterproof bathroom paint and I have installed new hardiebacker behind the shower.

Many thanks

 

[Dave]

Hi Dave,

Thanks so much for responding.
It's only half a wall (about 1.3m wide by 1.8m high) - I have attached a photo.
The rest of the wall is covered in stable waterproof bathroom paint and I have installed new hardiebacker behind the shower.

Many thanks

Ah i see your dliemma , i wouldn’t touch that paint , looks like an old lead based one. If the skim coat is. Intact and not loose , then slurry prier it ( sbr mixed with adhesive ) and then when tacky skim over with adhesive and tank over that... follow instructions on the tanking kit for priming.

 

[Loldie]

Ah i see your dliemma , i wouldn’t touch that paint , looks like an old lead based one. If the skim coat is. Intact and not loose , then slurry prier it ( sbr mixed with adhesive ) and then when tacky skim over with adhesive and tank over that... follow instructions on the tanking kit for priming.

Thanks so much, thats really helpful!

 

[Johnjoe2020]

Is it possible to tank over a wall that is part painted? I have applied the primer from the tanking kit Everywhere already. It’s a shower bath the top quarter of the wall is painted the rest is plaster that has had the old adhesive removed. The part that is painted won’t come into as much contact with the water. But plumber advised the whole wall should be tiled. Can I just go ahead with the tanking and will the tiler be happy just to tile over ? New to this ....