Grout around ceramic tile flooring coming off?

[tigercat]

We had ceramic tiles installed 2 yrs. ago and the grout around them has been coming out since 6 months after installation. They came and regrouted the bad areas once but now more and more grout is just coming out. I am getting big chunks of it when I sweep. What would make the grout come out does anyone know?
tigercat

 

[BunsenH]

The floor may be flexing when you walk on it. An unstable sub floor would cause this. The grout is the weakest link, cracks and loosens.

Are the tiles loose?

When replacing small patches of grout, I mix latex or acrylic caulk, the grout, and a little water. This allows some flexing of the grout and makes it less likely to crumble when stressed.

 

[POOHsie]

Agree with PP. IMO, probably your floor underlayment is the original plywood or perhaps an old vinyl floor, and possibly some thin plywood on top of that. It is flexing too much for a tile floor, which will try to flex at every grout joint. Small cracks are becoming big cracks, and that's what you're experiencing 2 years later.

Any tile surface (counters, floors, tub surrounds, etc.) should have a base of Cement Backerboard. It's screwed down into your subfloor and it'll keep your floor stiff. Plus it's the right product to handle the ThinSet cement that you apply under the ceramic tile. If you have a bad base under the tile, first thing that goes is the grout, then tiles will crack, leaving sharp edges. Last week on "Rescue My Renovation" with John DeSilvia (DIY Channel), I saw a show about a horrible kitchen job, with a badly cracking new tile floor. The tile cracks were so bad that the homeowners had Duct Tape on some tiles so the family wouldn't cut themselves when walking barefoot. Basically, the floor was a total loss. It had to be removed. Then Cement Backerboard screwed down, and new tile installed on top of that.

The show was called "The Case of the Crooked Cabinets." It isn't scheduled again until Sunday, Aug. 3rd at 1:30pm (check your local listings). I found the show on YouTube but you have to purchase it for $1.99.

You could try removing a loose tile and see what's underneath your floor.

http://www.diynetwork.com/rescue-my-renovation/case-of-the-crooked-cabinets/index.html
http://www.youtube.com/watch?v=b-zBGfR7Z1g

 

[Bella the Ball 360]

The floor may be flexing when you walk on it. An unstable sub floor would cause this. The grout is the weakest link, cracks and loosens.

Are the tiles loose?

When replacing small patches of grout, I mix latex or acrylic caulk, the grout, and a little water. This allows some flexing of the grout and makes it less likely to crumble when stressed.

That is a good idea but what happens if it gets on the tile? Does in smear or do you wash it immediately?

 

[tigercat]

There was only base flooring under the tile and they really screwed that down so that it wouldn't move. The old floor had been removed. I have one tile that has a small crack but it is by the sink and I am not sure if something hadn't fallen on it. There are no loose tiles at this point. I know they put something under the tile to make it stick. The contractor who did it keeps saying that he is unsure why it is doing it.
tigercat

 

[Christine]

Two of my bathrooms have been doing this for quite some time and I don't believe it is the subflooring.

I had grout that was getting discolored but it was definitely not coming up. I had someone come in and regrout two of the bathrooms and, like you OP, within a few months, bits of it started coming up. It never did that before and I know that nothing just decided to change with the subflooring.

I still don't know what it is but I feel like maybe the grout was not good, too porous, something...

 

[BunsenH]

That is a good idea but what happens if it gets on the tile? Does in smear or do you wash it immediately?

The caulk is water soluble and cleans up easily.

OP and others. Is excess moisture a problem? If the sub-floors are getting damp from a basement or bathroom wetness, the grout could lose its adhesion to the floor.

 

[laurafergie]

There was only base flooring under the tile and they really screwed that down so that it wouldn't move. The old floor had been removed. I have one tile that has a small crack but it is by the sink and I am not sure if something hadn't fallen on it. There are no loose tiles at this point. I know they put something under the tile to make it stick. The contractor who did it keeps saying that he is unsure why it is doing it.
tigercat

DH says (former tile guy until his knees gave out) the grout is coming up because the subfloor is flexing. It is almost impossible to screw down a subfloor tight enough so it won't flex. After all, the sub floor is more often or not screwed to wood itself. And THAT wood will flex too. Back in the day, he would not guarantee a floor or tile around water unless it had a sub underlayment of cement backer-board.

If you have a guarantee from your tile guy - you can either keep calling him every time the grout lifts or you can get second and third opinions from other tile companies in the area - and if they agree it is an underlayment problem, you could make your tile company re-lay the floor at their expense. (Good luck and get ready for a fight)

ETA DH adds that incorrectly mixed grout could be causing the fail, but it is almost always it is because of floor movement

 

[LJSquishy]

They probably should have installed cement board underneath which gives a lot of stability.

It's possible the installer didn't push the grout deep enough into the lines which could cause crumbling. When we installed our own porcelain tile floor in the laundry room (we are DIYers) we used a special grout (or maybe it was the thinset underneath, I can't remember) which allowed for minor movement without causing cracking. We used it because our house was built in 1905 so naturally things aren't always perfect. We also knew the vibration from the washer would put extra strain on it. It's been 3-4 years now and it's perfect still.

It has to either be an unstable subfloor, improper laying of the mastic/thinset (so the tiles aren't all sitting on a solid layer of it), or improper grouting. A thin layer of new grout will just crumble out...so if they didn't grind out the old grout, that is a problem.

Also, depending on the width of your grout lines, it determines whether sanded or non-sanded grout is used...I would assume you should have sanded grout.

 

[tigercat]

The funny thing is that the 2 bathrooms are fine. No crumbling at all. It is coming out in the hall and the entrance to the kitchen. We got a different grout the 2nd time they did it for those areas and it is still coming up. I will discuss the things you all of said with him.
tigercat