What did he put down before he put the tile in? Did he use hardibacker?

Radiant heat should not be a factor.

Go around the room and tap the tiles with the handle of a hammer. Do they have a hollow sound?

Your GC was negligent in installing a floor over a moving substrate. To be a sound subfloor for a tile installation, there should be no movement at all. You could end up with tiles cracking as well. What has he said about this?

If there is movement in your floor, regrouting will not solve the problem. It will just crack again. Listen to what the first install is telling you.

This post was edited by snookums2 on Fri, Oct 11, 13 at 13:17

You should start with GC who did it and see if he will guarantee the work. We had to regrout one of the colors of tile/grout that we had installed on our infloor radiant heated floor. We thought that who ever mixed that grout didn't do it right because adjacent rooms with a different color tile/grout were OK.

We ended up regrouting with a premixed grout that seems more flexible but I think perhaps we should have gone with epoxy grout. Epoxy is supposed to add to the structural integrity of the floor/tile.

We patched several times before deciding which grout to use. Patches with the original grout didn't hold up so maybe it was the grout and not the mixing. Patches with the premixed that was billed as crack resistant did well so we decided to pull it all out and redo the entire floor with it.

Caution about steam cleaning the premixed flexible grout. It shrinks and cracks so never steam clean it. Did you ever steam clean your current grout? If so that may have caused the problem.

Just throwing out a bunch of ideas...

The tiling industry has very specific standards about the amount of deflection that's permitted for tile floors. GW doesn't like it when a link is posted but find the tile forum hosted by John Bridge and ask the professional tillers there.

They will walk you through the steps of determining whether your floor meets the requirements for tile. If it doesn't, replacing the grout will not solve the problem, as it's probably being caused by the movement in the floor.

your grout (and eventually the tiles) will crack if there's ANY movement in the floor. Shoring up the joists underneath is nice and all, but he should have beefed up the subfloor so there wasn't any movement before he laid down the first tile. Look at your contract carefully to see if he will fix this or pay for having it properly done. This is an installation failure and not a failure of materials or improper care on your part.

P.S. That's a really ignorant statement, that he will use a flexible mortar to account for any movement. Someone who knows what they are doing would never consider installing over a floor with movement. You might want to get someone else in there to assess and fix the problem. That is very basic knowledge of tiling, not a technical concept.

It sounds like it could be a large area, which can get tricky and requires some technical expertise. So considering these issues, beware how and who you move forward with.

This post was edited by snookums2 on Fri, Oct 11, 13 at 16:17

I've done some DIY tiling after a lot of reading/research. I agree with the statements that a sturdy tile install cannot be done directly on an unstable surface. I used Ditra, which provides *some* isolation from movement. However, Ditra's installation specs list specific acceptable floor joist distances for different types of tile (stone vs porcelain). And they also specify exactly what should be between the Ditra and the joists (how many layers, etc). Additionally, in a very large space, I believe installs suggest expansion joint(s) where there is caulk rather than grout to allow some movement across such a large span. With extensive grout cracking and damage, it sure sounds like the installation was not done properly.

I have no advice but wanted to weigh in with my sympathy. So sorry that this has happened, especially frustrating I'm sure, since it's over a radiant heat layer. While replacing tiles in our master bath (a much smaller space) we chipped one of the wires for the radiant heat (and broke the circuit) and therefore had to first fix the radiant heat and then lay tiles again. Hope your GC is able to help. Best, oldbat2be

Quick thank you to everyone.
Now I'm more concerned about my tiles cracking, than just the little grout cracking.
Until then, no more jumping in this room...(difficult mandate when you have 2 little monkeys for kids... moved the Reebok trampoline to the livingroom)

My GC is coming Wed morning to take a look.
I'll show him this thread, and look up John Bridge.

thanks,
Amanda

Am I reading this wrong? Your GC firmed up the substrate before he tiled. So he diagnosed and fixed that problem. The tiler may have used old grout, mixed it incorrectly (too much or too little water), or used the wrong kind of grout for the size spacers he was using. If the tiles seem firmly adhered, you may just need re-grouting, which necessitates the removal of the old grout, a thorough cleaning, then re-grouting.

GC = tiler. He and his main guy tiled/grouted the familryoom.

One thing about this dark gray grout was that certain parts of it had dried w/ a white haze. The haze went away when I gave it 2 good washing/elbow grease.

The grout was a new box. Let's see if I can find the box.

thanks,
Amanda

Check over at JB to do your research, but I would suggest not showing him the threads.

Quoting EAM44 ... "Your GC firmed up the substrate before he tiled. So he diagnosed and fixed that problem."

What exactly did the GC do to "firm up the substrate"?The OP is not clear on exactly what was done here, so it's hard to make the call as to what exactly went wrong or whether or not the floor was prepared properly for tile installation. Did he install the tile directly over a wood subfloor without putting down any Hardibacker?

Go to John Bridge dot com forums and look under "forums"

In the blur bar at the top, there is the "Deflecto" which will give you a "go or no-go" as to your floor.....

Springy floor that later starts cracking? Highly suspect, over bad grout.