cracked time means movement in the system and its almost always installation error (unless you had an earthquake or a truck ran into your house and moved the subfloor).

hard to tell what caused it ... so many things could be at play or a combination of things:

1. improper subfloor constructions/thickness that may have caused deflection movement cracking the grout

2. excessive subfloor deflection/movement.

3. backerboard/membrane improperly installed (should be installed over a bed of thinset mortar and nailed/screwed every 6 inches).

4. no backerboard/membrane at all (tile can not be installed over a wood subfloor without a cbu/membrane unless its at least and inch and a quarter thick subfloor system).

5. tiles isntalled over the wrong adhesive (shoould be latex/polymer modified thinset mortar thinset mortar).

6. tiles isntalled over cured thinset mortar so proper bond has not taken place.

7. edges not caulked with a matching grout caulk which has caused cracking because of expansion and contraction. Tile always needs a perimeter caulked joint for expansion and contraction so no verticle obstructions can lock it in (like walls, posts, stairs, doorjambs.frames, etc)

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The right way and the wrong way.

Do it right everytime.

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fixing it depends on what is causing the problems.

call back the installer to fix it under his guarantee.

if the tiles keep cracking out then it isnt a bond issue, but a backerboard/membrane, or subfloor issue.

_____________________________________________

There are two ways to do any job.

The right way and the wrong way.

Do it right everytime.

_____________________________________________

http://flooringworld.org/

_____________________________________________

We have 3/8" subfloor. They nailed 1/2"OSB board and 1/4" backerboard. Total 1and 1/8" under the tile. They did not put thinset under when they nail the backerboard.

then your entire isntallation is ruined needs to be gutted and reinstalled using a setting bed of mortar under the backerboard.

what type of backerboard is it ?

download the instructions for yourself at their company website and you will see a mortar bed is REQUIRED.

they have no idea how to install tile right, so you might want to get them to reimburse you and get someoen in there that knows what theya re doing to do it right.

you dont have a 1 and once eight subfloor. You have a 7/8" subfloor becasue backerbaord isnt considered part of the subfloor but a tile system rigidity product.... not a subfloor product.

thye just didnt know how to install it properly and ruined the whole thing.

_____________________________________________

There are two ways to do any job.

The right way and the wrong way.

Do it right everytime.

_____________________________________________

http://flooringworld.org/

_____________________________________________

Your right it could be a lot of things that did this. Yes manufacturers do require a mudbed underneath the backerboard. But here in Florida with very bad standards and a get it done yesterday attitude; an underneath mudbed is rare. They also generally nail rather than screw it down. I'm not saying this is a good thing but I also never hear of anyone having problems doing this. It could still be a bond issue. Backerboard can suck the water out of thinset very quickly. They could've spread too much and didn't install fast enough. There could be a lot of deflection causing the tile to crack and pop. I've also seen a guy install 12x12 tiles using a 3/16 v notch trowel giving him an improper bond and his tiles were breaking on a concrete slab within the next day when his helper went to grout. But all of this is moot; the installers screwed up and most guys have a 1 year warranty on all labor. Call them back and tell them to fix it. It's their problem to figure out what's wrong. Also, if they're some fly by night we do everything type company; prepare to call a lawyer. Fixing this could get expensive.

nails OR screws are fine. Either is standard so long as you use galvanized or better.

_____________________________________________

There are two ways to do any job.

The right way and the wrong way.

Do it right everytime.

_____________________________________________

http://flooringworld.org/

_____________________________________________