"The GC is telling me the cracking will soon stop (in other words, within the first year) -- is that more BS or is it true?" Maybe yes, maybe no. In lightweight frame construction, the framing lumber can take several months to a year to come to an equilibrium of sorts. During that time, the wood can move. Moreso if the framing lumber was green (not pressure treated green, but non kiln-dried green) instead of kiln dried. Still...houses move. There is still seasonal movement due to humidity, subtle movement from wind loading, etc, etc. So while grout in changes of plane is more likely to crack within months of the initial installation, it could crack year after year. Or after every other year. Or never again. There's just not a one answer fits all solution. Cracked grout in decorative tile is cosmetic cracking. But cracked grout in a wet area like a shower represents another avenue for liquid water and water vapor to get behind the tile. Normally not a problem with a topical membrane like Kerdi or RedGuard. But still, industry standard, and best building practices, dictate that with inside corners in wet areas, it's best to use color and texture matched caulk instead of grout. Caulk flexes. Grout doesn't. If their caulk is failing, then they need educate themselves on how to properly caulk, prep, application and tooling, and on using the proper caulk. Mongo

One thing I try to always keep in mind, and have to remind my wife from time to time about, is that your entire home is hand-built. Every board, every tile, every stroke of the sandpaper on your drywall mud. So expect some imperfections - it's part of the deal. Also, time = money, so if you want a perfect tile job, expect to shell out more money and insist on perfection. We're just about to lay 30 sq ft of marble tile in the basement powder room and I'll be pushing my tile guy for perfection, as it's a small space and I don't mind paying for a few extra hours work to make it perfect. If I was tiling 300 sq ft I wouldn't be so interested, as a) the imperfections are less noticeable and b) perfection would cost a fortune. Don't let these things get under your skin, and if you want to feel better, go visit some open houses / show houses of places that cost 2-3 times as much as your house is worth and look for the imperfections there - they're everywhere and you'll see them if you look for them. Inside corners of drywall, tile lippage, grout inconsistencies, gaps in baseboard corners...

I'm not an expert so keep this in mind I think that you want a membrane on all shower walls. How I understand it is that the special cement board that goes up before the tile, needs to be either placed on top of a vapor barrier which is covering your studs, or have a membrane layer placed top of the board which is affixed directly to the studs. But not both barriers on the same installation. I think otherwise moisture will be trapped. The installation of the membranes will be a crucial factor when installing the tub too. It will be important that the membrane is not allowing water to drain behind the tub flange. I think someone had posted a nice drawing of this detail sometime back but I can't find it in my clippings to refer to. Tile and grout is not a waterproof surface. The reason for the barrier is to protect the wall studs. Evidently the cement board is not effected by water but will transmit water.

Bill! What a timely post this is - I've been meaning to ask you a very similar question. Wish I'd had time to take pictures first. I also have a brick fireplace, unpainted, with a wooden mantle surround. I want to tile it with granite tiles. My questions were: 1. Unmodified thinset or modified? I thought you're supposed to use unmodified with stone, but then again, modified on vertical surfaces. Based on your previous answer, I'm guessing modified? Recommendations? 2. The brick is in pretty good shape and smooth, but of course the mortar lines aren't completely even with the brick. Should there be an attempt to fill in mortar lines first, or skim coat, or should back-buttering be sufficient? 3. Caulk in between the wood mantle and brick portion of the fireplace? I know you're supposed to use caulk between wood and tile due to expansion, but wasn't sure how crucial it would be here. I'm horrible at caulking and want the grout lines and caulk lines as small as possible! 4. here's where I really need to take a picture to illustrate... But I have 7 1/2 inches between the surround and the fireplace opening (no metal insert, nothing like that) and 10 1/2 inches from the mantle bottom to the opening. This should make cutting 12 inch tiles really fun, since I can't use whole ones anywhere! I'm unsure whether to just the front or to go in about three inches inside to cover the side of the front brick, which you can see if you're looking at the fireplace from either side. I guess that's what I need to do, I'm just not sure how! Would I lay down thin strips there and caulk between the planes? Obviously, I don't want to get carried away tiling the inside of the fireplace, but I guess I should cover that red brick that's visible. I wish I had a picture ready so you could help me with layout ideas, LOL. I'm thinking I'll go up the sides and all the way to the top with the same width as the sides, and then cut the few tiles in between either side down so that they're equal. Or should I regard that top section as separate from the sides and cut accordingly? In other words, if the width at top is 50 inches, would you have your left and right tile match the 71/2 side legs or address the sides separately? Which will look better. The mantle is white and this is on a gold wall - I'm thinking maybe black galaxy because the black will look great and the gold should complement the wall well, but maybe it will look too showy and I'd be better with something like absolute black? There's a hearth recessed into the wood floor in front of the fireplace and it's multi-color slate. I'm not sure why I'm not continuing the slate, really. Oh, any recommendations for grout if I do the black galaxy?