I just recently had my bathroom redone and also had some slight cracks in the grout for the first couple of months which my contractor said is normal due to some settling, he has since fixed those cracks. But there was absolutely no leaking at all due to these cracks and the waterproofing was done very well. the fact that u are having all of this leaking shows that your waterproofing must not have been done very good. I'm no expert, but I would say that it has to be redone.

Thanks for your input Chris. This is what I think may be causing the problem. I just want reassurance that have grounds to suggest that this is the best course of action to take. We are developing the rest of the house and are at a standstill until this is sorted out. I don't want to damage a brand new kitchen if the ceiling comes down again!

Hi Creative Tile Eastern CT. Thank you for your response. From what I can gather having spoken to the plumber there is no waterproofing membrane behind the tile as he claims that the tile and grout is not permeable. I believe that he has just adhered the tiles straight onto the plastered wall. He is saying that the water is getting through the cracks in the grout likely caused by an unforeseen issue with our house. He says that the 'upstand' installed at the base of the tiles should catch any water runoff.

I was going to ask the same question as Creative Tile. What did they use to waterproof behind the tile? Did he at least use cement board behind the tile?

Tile and grout are not waterproof. Sounds like it's a complete do-over with someone who's competent.

Simply ask if the shower could be used without tile & grout. If the answer is no then it needs to be redone properly. The plumber is not a tile setter.

If that is what he believes as a plumber, and attempted to add tile setting to his reportoire I would be VERY leary of his plumbing skills as the line of BS he thru at you is incredible.

You need cement board with a surface coating like redguard or hydroban. All seams to be taped with mesh tape and thinset.

IMO - plumbers shouldn't be building showers.

You do not need a cement board with a liquid applied membrane( redgaurd & hdroban) geoffrey_b has correctly presented one approved option. Many of us prefer sheet membranes over liquid applied. There is also a new generation of foam board that will provide vapor proofing as well as waterproofing or 4 mil. poly behind the cement board. There are several acceptable methods. You just need a qualified installer to properly execute the selected method. He/She will not have Plumber on their business card:)

90% of the time, it is a shower pan failure, and obviously in this case, as stated, proper waterproofing prior to install. Professional only (vetted tile contractor) can do this (but it is a tear out and re-do).

Tile and grout is not permeable

I'm not a plumber or a tile setter, but I know more about what's required for a leakproof shower than he does.

Reading here at GardenWeb, I know that tile and grout are not waterproof. Your guy is just not informed.

Yes, we have bathrooms done "the old way" and sometimes the tile above the bathtub did stay for many years. But how many have rotten walls and floors behind them? Do yourself a favor and read up on how a shower should be built before you hire the next person, and talk about their methods and products before you hire. People are still out there, putting up materials worth thousands of dollars, not knowing what they are doing. After the leaks ruin other rooms in the house, all has to be torn out and redone. It happens all the time.

Here is a current thread:

http://ths.gardenweb.com/discussions/4654503/wall-underlayment-for-shower-best-practice?n=4

Cracking grout and leaks point to movement and poor (or no) waterproofing. The tile could also be poorly adhered to the wall; what was used to set the tiles, mastic or thinset, and was it correctly applied. To solve this you probably need to address the basic structure of the shower. You say that the tile is set "onto the plastered wall". Was that an old wall?

I think you will need to take everything back to the studs. make sure you have a solid structure and then get an experienced professional to install a correctly waterproofed shower.

Glazed tile is pretty impervious to water....the joints and the grout can let water through.