Tiling onto plaster for shower/bath

[LiamH83]

Hello,

I’m doing a DIY bathroom job and would be very grateful for some advice.

The bathroom is in a 2nd floor flat in a converted Victorian house. The bathroom walls for the corner into which the bathtub and shower will sit appear to be dry walls with wool insulation, foil backed plasterboard with thick plaster on top set around wire mesh.

There was an existing bathtub but no shower. We’d like one so I have chased into the plaster to make space for copper pipes (please see picture). I had been planning to wrap the pipes in duct tape, secure in place with a piece of wood (temporarily), whilst filling in the chased holes around the pipes with cement and then plaster before re-tiling the back wall. I’m aware of the general weight limit of 20kg/m2.

However, I’m now concerned re the possibility of water damage from the shower if the walls have not been properly tanked. Is this something I should worry about or would you expect the area to be water tight once tiled and sealant applied to the corner areas?

I suspect the existing tiling would have been “splash proof” but perhaps not shower proof.

I have considered stripping both walls right back to the plasterboard, screwing on tile backer board and priming, taping, etc., which I’d rather avoid but will do if people think it’s necessary.

Or any other suggestions would be appreciated.

Thanks!

 

[Joe8189]

Hey Liam
I think your solution of removing the old tiles is right. Use 6mm backer board and fully tank the area. At least you will have peace of mind that when you are having your shower, it wont be seeping down the wall behind the tiles. 🙂

 

[Kevbos]

Hello,

I’m doing a DIY bathroom job and would be very grateful for some advice.

The bathroom is in a 2nd floor flat in a converted Victorian house. The bathroom walls for the corner into which the bathtub and shower will sit appear to be dry walls with wool insulation, foil backed plasterboard with thick plaster on top set around wire mesh.

There was an existing bathtub but no shower. We’d like one so I have chased into the plaster to make space for copper pipes (please see picture). I had been planning to wrap the pipes in duct tape, secure in place with a piece of wood (temporarily), whilst filling in the chased holes around the pipes with cement and then plaster before re-tiling the back wall. I’m aware of the general weight limit of 20kg/m2.

However, I’m now concerned re the possibility of water damage from the shower if the walls have not been properly tanked. Is this something I should worry about or would you expect the area to be water tight once tiled and sealant applied to the corner areas?

I suspect the existing tiling would have been “splash proof” but perhaps not shower proof.

I have considered stripping both walls right back to the plasterboard, screwing on tile backer board and priming, taping, etc., which I’d rather avoid but will do if people think it’s necessary.

Or any other suggestions would be appreciated.

Thanks!

View attachment 123635

You cannot tank half a room , all you do is push a future leak of water to an untanked area ! There is no point tanking walls down to Bath height , water will always find least path of resistance , that now being the point of most movement , weakness , vulnerability the bath edge , your tiles and probably silicone , the silicone will deteriorate over time , a gap will open and water flows to unranked area

 

[Adamskionline]

Hello,

I’m doing a DIY bathroom job and would be very grateful for some advice.

The bathroom is in a 2nd floor flat in a converted Victorian house. The bathroom walls for the corner into which the bathtub and shower will sit appear to be dry walls with wool insulation, foil backed plasterboard with thick plaster on top set around wire mesh.

There was an existing bathtub but no shower. We’d like one so I have chased into the plaster to make space for copper pipes (please see picture). I had been planning to wrap the pipes in duct tape, secure in place with a piece of wood (temporarily), whilst filling in the chased holes around the pipes with cement and then plaster before re-tiling the back wall. I’m aware of the general weight limit of 20kg/m2.

However, I’m now concerned re the possibility of water damage from the shower if the walls have not been properly tanked. Is this something I should worry about or would you expect the area to be water tight once tiled and sealant applied to the corner areas?

I suspect the existing tiling would have been “splash proof” but perhaps not shower proof.

I have considered stripping both walls right back to the plasterboard, screwing on tile backer board and priming, taping, etc., which I’d rather avoid but will do if people think it’s necessary.

Or any other suggestions would be appreciated.

Thanks!

View attachment 123635

You're definitely setting yourself up for future problems by just doing half a job! Aesthetically it'll also probably look a bit awkward if you have new tiles and grout abutting the old part as well.
Best thing to do is take it all back and make good, and give yourself a good base to start the new tiling. A 6mm backer board will do the job, but you can also look at paint on waterproof solutions such as watertite or a belt and braces option such as Schluter Kerdi 200.

 

[davidjohnsir]

As multiple people have pointed out, I too feel doing half the job is risky and it would better if you replace the whole area.