Wall behind bathroom tiles is wet, help

24 Aug 2007
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United Kingdom
I recently moved into a new house, the first thing I did was completely gut the downstairs bathroom, removing a ghastly pink suite. Although there was signs of previous damp beside the bath, it was now completely bone dry. I had a nice new white suite put in and my father tiled the walls around the shower/ bath.
The bathroom looked absolutely superb with sparkling white tiles. After a few weeks I noticed that the tile grout around a small section above the bath had fine cracks in it and the grout around 12 or so tiles was badly discoloured. I know that grout discolours easily but this was ridiculous. Then I noticed that the 12 or so tiles were starting to go grey instead of being white.

A few days later after inspecting the tiles again, I noticed one looked a bit loose and it came off really easily. The tile was totally soaking all the way through, they are bathroom tiles by the way! and the wall behind was soaking wet. At first I thought maybe the water had got into the cracks when having showers but it seems far too wet for this and the grout was real hard but the adhesive was soft. I thought maybe water was leaking in from elsewhere behind but I can't find anything at all, there are no pipes near and the wall is dry at the bottom and at the top, just a middle section of wall is wet. The wall itself is solid, it is a compacted straw type of plasterboard and so the source of the water is a complete mystery.

Could water leaking in through tiny cracks in the grout be enough to soak the wall so badly in such a short space of time. Please can someone help.
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I dont think so franco if its not damp top and bottom the tiles are soaked and the adhesive is loose. Can you post a pic for us all to have a look at. Whats behind the wall is it another room? could there be pipes from that room?
Will try and post a picture, I ended up taking 19 tiles off and it doesnt seem to have spread any further. The reason it isnt wet below seems to be because the bath sits into the wall by about 1inch 1/2 (they must have made a mistake during the build because the space is so tight for a standard size bath. So when I took the tiles off, the wall where the bottom tiles were is much wetter because the water essentially had know where else to go as it was well siliconed in. The wall is drying out really quick which hopefully suggests there is no leak.

The other side of the wall (2 1/2 inches) is the kitchen but no pipework in that part of the kitchen area. It was only put in a couple of weeks ago. I fear that all the work going on in the house (I had a new boiler put in as well) has maybe made the grout crack. I am now holding off tiling the kitchen side until it I know what has happened. I am really surprised the grout cracked though as the rest looks really solid.

The wall where I removed the tiles is now a bit of a mess, any good methods of sealing the wall with anything once it has dried thoroughly before re-tiling.
I can recommend the Dunlop tanking kit http://www.bal-adhesives.co.uk/dunlop/index.html
Click videos and then select the bottom video on that page. You may need to download Adobe flash player but it only takes a minute.
This will waterproof the walls, but if there's movement in the walls the grout will crack and you'll have discoloured tiles again.
Might I recommend you use powdered adhesive too - pre-mixed tub stuff takes an age to go off properly (and even longer in damp conditions). Use a decent powdered grout too.
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remove loose material and dust down, apply a coat of PVA glue to seal and retile, are you doing this franco or has dad got the task
Do not use PVA in a bathroom, any moisture getting to it will result in the PVA getting tacky, not the ideal surface for tiling.

Follow gcol,s advice...
The Dunlop product looks good but does anyone else recommend any products that would waterproof or seal the wall before I apply the Uni Bond Shower and Bathroom adhesive i have.

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