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That is not normal. When houses settle, it is the grout line that is on 90 degree surfaces not on a flat surface, which should have been caulked anyway in the first place. Your photo looks like a flat plane to me and no, that is NOT normal, especially if you haven't been in a good-sized earthquake lately. ;-)

-Babka

Agree with Babka.

Cracking grout is not normal within the plane of a tiled wall surface. Is there anything on the other side of that wall that might have caused the wall to move?

You could get shrinkage cracks in the grout if unsanded grout was used in a grout joint wider than 1/8", or if too much water was used in the grout mix. Both of those would be installation errors.

The only place you could "expect" to see cracked grout in typical lightweight construction shower is when the wall-to-wall inside corners are grouted instead of caulked. And that's not a failure of the material. Again, that would be due to a flawed installation.

Another thing I don't like about your photo is the shadow line on the vertical grout joint. Looks like he raked too much grout out of the joints due to improper cleaning. The grout should be flush with the edges of the tiles.

The grout is not flush with the tiles.

We have no cracking where two planes meet in this shower, only cracks on the vertical walls. Behind the tile is cement board with red guard. What went wrong here? Do we need to take all the grout out?

I would think that "what went wrong" is actually a settling/building issue; rather than a tiling issue...
But, Mongoct is best to answer.

Isn't it common for house's to settle? We have nail pops and some cracking in our plaster crown in one room, but nothing severe. What concerns me is that our builder said cracks in wall grout aren't common.

I live in CA with earthquakes. Things crack along sheetrock (drywall) seems, or where planes change, around door frames, etc. Rarely on a flat wall. Something else is going on.

-Babka

Ugh. Ok, so what could it be? How do we figure out what's causing this?

I talked to the tile setter about it today and he assured me this is normal and he will fix it, but that he doesn't need to take out all the grout and redo the whole shower.

So what does the tile setter say caused it? And what will he do to correct it? If he just fills in the crack with matching caulk and calls it a day, how long will it last???? Does he guarantee his work? and for how long?

-Babka

He said it is from the house settling. I'll ask how he plans to handle it.

Sure, a house settles. Some is normal. Some isn't.

If it's the house, you should be seeing other evidence of it settling. Are you also getting cracks in your drywall in the bath? It should show up around windows and doors more than in the middle of a wall. What about the crown molding? Is it separating from the ceiling? Get on a ladder and look at the caulk between the molding and the wall and the molding and the ceiling. What about your doors? When you close them, do they stick? Are there even gaps around them? Get a tape measure and don't just eyeball it. Windows getting sticky? What about the brick on the exterior of that area? Does it also have cracks in the mortar? Is the foundation visible? Put a laser level on it to see if that corner has subsided.

You've got to personally investigate what the cause might be. Your builder has a vested interest in it not being "his" problem. And that's been the problem all along.

I see no evidence of cracking other than a small joint in our master bath plaster crown moulding. I've not taken a level to the foundation yet. Nothing is sticking or cracking.

Sounds like your answering your own question then.

I believe Mongoct mentioned early on that causes that create your symptoms are 1) watered down grout, 2) unsanded grout on joints >1/8". Though yours looks sanded to me. I wouldn't be surprised if the grout was incorrectly installed. Mongoct also noted that the joints were too shallow and that it should have been flush with the tile. I am thinking that there isn't much integrity in the grout. But I am just taking info that is on this thread and making an assumption.

It's definitely sanded grout in the whole shower. If it makes any difference, the unsanded grout he used in our kids subway tile shower has lots of little holes, almost as if bubbles had popped while the grout was dry. Perhaps that speaks to his method of mixing or installation? I am new to all of this, but am trying to gain as much information as I can. I'll post back after he returns to deal with this in a few weeks and I'll ask him not to rake the joints after he's grouted.

By the way, is all grout supposed to be flush with tile? Our floors and shower walls and floors all have the grout recessed from the face of the tile quite a bit. Thanks.

Is the cracking just along the grout of that one tile or does it continue across? It looks like it goes down the right side a bit too now that I look really closely. It just seems to me that even when a house settles, cracks show up where two opposing surfaces shift or twist and get out of line..most likely at the weakest place along the stress. The grout looks (to me) like a soupy mix, not very strong, and as mongoct pointed out, parts look too shallow.

Perhaps you could pay a one time fee for an industry pro to take a look and make a determination. We had to do that with a floating floor that kept making loud popping noises when we walked on it. It turned out that the floor had been laid improperly and had to be redone.

I think you are getting the run-around, and I SO sympathize with you. Each guy is passing it off on the other guy. Can you get them both with you in the same room at the same time looking at the same problem? They may be able to shine on a home owner, but with each other, they will have to come up with a really good explanation to defend their work. Good luck!

-Babka

How can you tell the grout wasn't mixed well?

The cracks are along horizontal and vertical areas of the walls in the shower, not just as is seen in this photo.

" If it makes any difference, the unsanded grout he used in our kids subway tile shower has lots of little holes, almost as if bubbles had popped while the grout was dry. Perhaps that speaks to his method of mixing or installation? "

Yes it does. Too much water was used when mixing the grout, he did a lousy job of working it into the joints, and then when he cleaned up he had poor timing in that he didn't let the grout sufficiently set, then he used too much water on the sponge and too much pressure with the sponge.

Poor workmanship by the tiler.

In my earlier reply I asked if there was anything on the other side of that wall that might have caused the wall to move. What I was referring to was if there were any built-ins added, or any heavy shelving on the wall. Any "construction" in the room on the other side of this wall that might have resulted in banging on the back side of the tiled wall.

ie, was there a chance the tiler did a good job. But then carpenters came in and whacked the other side of the wall, causing the tiled wall to deform and the grout to crack.

But since your tiler hasn't raised that concern, I'll go back to my initial assessment:

Poor workmanship by the tiler.

This post was edited by mongoct on Wed, Aug 14, 13 at 0:50

One shower wall is an exterior wall, another has no cabinetry on the other side, and another has very minimal cabinetry.