Help - bulging shower tiles

[socco]

Hi,
Having built and installed a fully tiled shower cubical in my bathroom - a year on, I am still experiencing a reoccurring problem with the tiles on the back wall of the cubical. After about 3 months of finishing the work one of the large landscape tiles started to bulge out, about 3 courses up under the shower controls. I took the tiles off and the plaster was bone dry underneath, so I retiled and grouted again. 3 months later - same problem, in exactly the same location again. Tiles took off again, dry plaster seen and I re-tiled again. 3 months later - same problem & same repair done. Its happened yet again and I am left scratching my head as to what is causing it.

Any advice would be greatly appreciated before I start my 5th repair!!!!

What else I can tell you is - Its happening on an external cavity wall, its an upstairs bathroom and there is no damp in the walls and its happening on the tile which covers the upward water pipes - which are plastic (not copper).

 

[Gazzer]

What adhesives/grouts are you using and what tiles?
Are the water pipes making the wall hot?
Please leave as much info as possible so we can try to help you out.

 

[DHTiling]

Have you put expansion joints in the corners..this could be thermal/moisture expansion causing the tiles to bulge......

 

[socco]

What adhesives/grouts are you using and what tiles?
Are the water pipes making the wall hot?
Please leave as much info as possible so we can try to help you out.

Thanks for you response so far - The tiles are called 'santa barbara' and are limestone look ceramic tiles 12" x 8" - hung landscape. The adhesive is called supergrip ceramic tile premix adhesive as recommended by the tile shop and the grout is wateproof grout used for swimming pools - again, as recommended by the tile shop where the tiles were bought from (the ceramic tile centre - in portsmouth). The wall isn't hot to touch (difficult one to answer as obviously the shower is running at the time) but the problem does occur on the side of the hot water upright feed each time.
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There is a gap but it has been grouted and then had sealant run down the corners. but the gap is no more than 2 mill.

 

[versatilene]

If it's the tiles covering the upward pipe it sounds like expansion due to heating of that pipe. Don't know how much you want to do but try cuting out, insulating the pipe and retiling.

 

[DHTiling]

I would rake the grout out from the corner joint then re-Silicon...stick the tiles back on with a cement based flexible adhesive , this will then withstand the temp from the pipes and give a true corner movement joint.....good luck....

 

[Gazzer]

Not familiar with that adhesive but seeing as its only one area affected i wouldnt think it was the problem. Is it a waterproof adhesive? but then again it lends a thought to as why the other tiles have not the same problem.
I would be looking along the lines of heat from the pipe. Its rare for that to happen as the heat shouldnt be that bad.
Could you give the width of the wall that is affected. Not sure about expansion joints due to the fact that once again, its only one area affected.
Is there any movement at all in the wall when you press against it?
This could be hard to pin point as it could be a number of things.

 

[socco]

Yeah that was going to be my last resort but think i may have to bite the bullet cheers
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Cheers for getting back to me!,
The wall is about 800 mill only the size of the shower tray and dont think the adhesive is waterproof, but like you said it has not caused any other problems on the two other walls.