New Tiles Buckling from Wall

Hi without seeing it,it sounds like that section of wall is getting water penetration or the wall behind is damp also it depends on what adhesive and grout is being used IE powdered or pre mixed adhesive for instance,powdered being the best and a high flexible grout as I say it is hard to identify the problem 100% without seeing it but thats what it sounds like in my opinion

Hi there. There could be an issue with moisture penetrating the wall or it could be the incorrect products were used when the tiling was originally carried out. 1. Is the wall in question solid or plaster board. If it's plaster board then this is not resistant to moisture and could be a potential reason why the tiles are 'swelling'. There could be a leak somewhere and water is getting to the plasterboard. 2. Was the wall originally primed with SBR primer? 3. Are the tiles ceramic or porcelain, what size are they and what adhesive was used. If they are ceramic then ready mixed adhesive could have been used but as a rule only with a tile up to 10" in size. The reason being that ready mixed adhesive will only fully dry to a depth of 4mm. If using a tile up to 10" an 8mm trowel could be used, leaving a bead of adhesive 4mm thick-which will fully dry and leave the tiles bonded to the wall. If the tiles are bigger than 10" then a bigger trowel would need to be used, which would leave a bead of adhesive greater than 4mm-and as a result of this will never fully dry. If they are porcelain tiles than then a flexible cement based adhesive would need to be used, as ready mixed adhesive will not bond the tile to the wall. 4. Was the adhesive and grout waterproof or not? Hope this helps, if you have any further question do not hesitate to contact me, Paul.

As the comments above it is hard to tell without seeing the job in question. However, if I was doing the Tiling, firstly I would make sure cement boards were installed (If replacing plaster boards) as these are water/moisture resistant. Secondly I would use a 3 part tanking system for the walls (Primer, rubberised mesh membrane, latex paint, 2 coats). As for the adhesive, an S1 powder (Highly flexible) that is suited for bathrooms/shower rooms and that goes for the Grout as well. The grout shouldn’t be crumbling from the tiles unless your builder grouted the tiles before the adhesive fully cured, if that was the case, the adhesive has sucked the water/moisture from the grout therefore not allowing it to cure naturally. If the grout is crumbling from the corners were the tiles meet then the builder is at fault. Silicone should be used in corners and edges as it compensates for any movement of the tiles/surface. Hope this might help a little bit. Mike.