New wall tiles cracking and bowing out

[Pidders]

About 10 months ago we had our bathroom re-tiled with 15.5"x9.5" tiles over existing (smaller) tiles. We have now noticed that a number of tiles in random places on the external walls (brick) have numerous hairline cracks and are bowing outwards, although the grout between the tiles is still intact. When tapped there is a hollow sound as if the tiles are no longer fixed to the wall. There is no problem with tiles fixed to the internal walls (breeze block).The tile fitter is blaming faulty tiles whereas the tile supplier is blaming the installation. I do know that during the installation the fitter had to use thick layers of adhesive due to the walls not being true.
Any thoughts o what is to blame? We are stuck in the middle and don't want to end up paying for the re-tiling!!

 

[1john]

If you can contact trading standards they can advise you of the best course of action to take, you could advise the fixer too, there is a problem somewhere but it could be installation method, adhesive problem, tile problem, substrate issue.... almost anything.

 

[Richard C]

About 10 months ago we had our bathroom re-tiled with 15.5"x9.5" tiles over existing (smaller) tiles.

That’s the first mistake, it can be done but it’s never a good idea; existing tiles should always be removed unless there is very good reason not to do so & then correct preparation is all inportant. Using the wrong/cheap adhesive/grout will lead to adhesion problems as will incorrect/no preparation of the existing tile base. Tiles that size should also be fixed with a cement powder adhesive not tub ready mix, do you know what type was used? Laying the adhesive on too thickly will also give problems, especially with tub mix over existing tiles, if the walls were uneven they should have been levelled off first, rather than trying to use great gobs of adhesive during tiling; there is a limit to how thick you can apply it. Extremely unlikely it’s due to faulty tiles, ask him to define exactly how they are “faulty”!