shower cubicle

[redant1]

Recently had shower tray replaced-plumber removed old tray and row of tiles above the tray. He found that the plaster board had been impregnated with water and replaced some of the board. A check under tray has shown that water is leaking behind the tiles, mastic seal to tray is ok. Have checked grouting and found loose grout and after scraping some out have discovered a void behind the tile joint; it seems the board may not have been completely joined. Any ideas as to best way to fill the void so I can grout on top without removing all the tiles?

Many thanks.

 

[Richard C]

Recently had shower tray replaced-plumber removed old tray and row of tiles above the tray. He found that the plaster board had been impregnated with water and replaced some of the board.

Replaced it with what?

A check under tray has shown that water is leaking behind the tiles, mastic seal to tray is ok. Have checked grouting and found loose grout and after scraping some out have discovered a void behind the tile joint; it seems the board may not have been completely joined. Any ideas as to best way to fill the void so I can grout on top without removing all the tiles?

Did your plumber not check & advise the soundness of the rest of the shower installation when he fitted the new tray? Is the water likely to be coming from a concealed shower fitting or pipe or is it just getting behind the tiles & onto the floor? Absolutely no point in sealing it up if the leak is behind the tiles!

It sounds like you have a plasterboard base & it may well have disintegrated behind the tiles as well as where it butted the old tray; best check out some other areas & see what you find. Providing there is no internal leak, you could try injecting some silicone sealer in there but if the plasterboard base is collapsing, I fear your shower is doomed my friend & it may be best to do a complete refit. If so & before you start, either DIY or employing a “pro”, do some research regarding how it should be done properly as you don’t want to replicate the problems you currently have in just a few years time. It’s a sad fact but not all those who call themselves “tradesmen” actually know what they are doing!

 

[redant1]

Mant thanks for your reply, Richard C. Replaced it with what? Replaced a 4 upstand plastic tray with a stone resin tray, shower is in a corner so 2 sides are against the walls. This was a new-build so I guess builders used cheapest tray they could. It appears that the water had got underneath the upstand on one wall and damaged the plasterboard. No water is coming from a concealed shower fitting. It seems that the plasterboard did not butt together when replaced and there is a gap behind where the tiles meet one tile up, so the grout has nothing to adhere to. I note your suggestion of injecting some silicone sealer in there, would grout adhere to this? If not could I try filler, such as polyfiller, to try to take up the gap and grout on top? (The water appears to be running both behind the tiles and behind the plasterboard.) I hope this makes things clearer, I can see it but it's difficult to describe!! Look forward to any suggestions you can give.

 

[Richard C]

Replaced it with what? Replaced a 4 upstand plastic tray with a stone resin tray, shower is in a corner so 2 sides are against the walls.

I meant what did he replace the plasterboard he took out with ; if he’s’ just put bits of ordinary PB back in there, it probably won’t last. It should at least be Moisture Resistant PB (green) but even that’s not ideal in such a vulnerable area at the bottom of the shower.

It seems that the plasterboard did not butt together when replaced and there is a gap behind where the tiles meet one tile up, so the grout has nothing to adhere to.

So the plumber who did the repair hasn’t done it properly. The last thing you want is a gap in the board behind the tiles; is it a timber stud wall or is it a block work wall with PB stuck onto it (dot & dab)? If it’s a stud wall, water will get into the timber used to construct the stud behind the PB & this will also rot out. If he's just bodged it up behind there, I’d call him back. He should also have warned you that in all probability what he's done is only likely to provide a temporary fix.

I note your suggestion of injecting some silicone sealer in there, would grout adhere to this? If not could I try filler, such as polyfiller, to try to take up the gap and grout on top? (The water appears to be running both behind the tiles and behind the plasterboard.) I hope this makes things clearer, I can see it but it's difficult to describe!! Look forward to any suggestions you can give.

Forget using Polyfilla it will just dissolve. Grout won’t adhere to silicone & I suggested this as a means of sealing between the tiles instead of grout; you could try just packing it out with grout but how much of a gap is it? I assumed you could just see the void behind the tiles through the gap between the tiles. If the gap between the boards is large, it begs the question just how much of the tiles are actually stuck onto something or are they mostly hanging in fresh air! I think whatever you do is only going to provide a temporary fix, it really needs to be sorted out properly even if that means removing the tiles again.

 

[redant1]

Many thanks for your comprehensive reply, Richard C. To answer your questions, it is a stud wall and I'm sure he has used ordinary plasterboard (but I am also sure the plasterboard that was removed was not Moisture Resistant PB!-as I said was a new build in 2002 by Bryant Homes and they put in stud walls between rooms. This is the wall between the en-suite and a bedroom.) The gap is about 1/8th of an inch and the tiles do appear to be well fixed, and as you say the void can be seen behind the tiles. I think your suggestion of a fix by packing out with grout, even if only a temporary measure, is probably the best solution. I will monitor closely and be aware that I will have to take remedial action in due course.

Many thanks for your help and advice.