Looks like the floor is flexing and it's telegraphing through the grout lines.

Yes, tile being what it is, there are industry standards in place for preparing a good solid, sound substrate and how much deflection is acceptable in tiling installations in order to avoid situations like yours. Essentially, the floor should not be moving or the tile and/or grout will crack, further, allowing water to escape. Once the flooring person starts to lay that floor, he has taken ownership that it is a good foundation.

Now, whether anything else ever enters into it or there could be unforeseen conditions no one could know, someone else might be able to answer.

Do you know anything about the details of the install? Did you watch at all? Does the contract state any details or specs for how the job will be done. Say anything about "to be installed per industry standards, ANSI ASC ... "?

Thank you snookums. I have complete faith in our contractor to do the right thing, not so much faith in the sub's tile setting skills as this is not, unfortunately our first issue with tile in the renovation. Problem is, the contractor tends to turm to the tile setter as the expert.

I tried to snap daily pictures, but some days other responsibilities got in the way. I am going to post what I have. If you don't mind telling me if the images give you any clues, I would appreciate it.

pic 2

edited- wrong pic posted. image removed

This post was edited by sparklebread on Tue, Apr 2, 13 at 19:06

I think there are some tiling experts who visit here but you can find in-depth assistance over at John Bridge which is a tile trade hangout with a help forum.

"Is floor flexing normal on the second floor of a twenty five year old home? Is this a possible install issue?"

The felxing is called 'deflection'. All beams (floor joists) will have some deflection when weight is applied.

Tile being a ridgid material doesn't take well to flexing, and thus the tile cracks or the grout cracks.

The person who builds the shower should be aware of this issue, and how to prevent it.

For instance, maybe screwing down and additional layer of plywood would stiffen the shower floor, and lessen the deflection.

It looks to me like they will have to redo the shower floor.

Geoffrey~ I was afraid it might be a tear out!

I did a GW and JB site search (thanks for the direction, snookums) and read about a test where you tap on the floor with your knuckle or plastic end of screw driver. If it sounds hollow then there might be underlying issues warranting a tear out.

Sounds hollow under the cracked area. Will report back for future reference.

Thank you!

So sorry to hear. It is heartbreaking and tiresome. What a mess.