Less than a year ago I had several rooms tiled with a beautiful ceramic tile. Now the grout is cracking, the tiles are loose and I can't get the contractor to come back. (Don't even go there with me:mad: ) I have begun pulling up the loose tiles and have the motar to contend with below. How best do I prepare the wood subfloor for this tile to be reinstalled? Any suggestions would be greatly appreciated.

Did he tile directly on the wood sub floor or was backer board put down first ? I have used a grinder and a small chisel to loosen old mortar under tiles that were being replaced but its messy to say the least and time consuming. You are obviuosly not happy with your contractor and if backer board was not used I have a pretty good idea why ? Are you replacing all the tiles are just many problematic ones ?Eitherway its a lot of work and the only way I know to get that old mortar bed loose is with some type of grinder ,scraper, or chisel. If I missed anything let me know. GOOD LUCK, AC

Uhhhh... thanks... looks like I have a big job in front of me. I am just replacing the "problematic ones". I have pulled them up and am looking at the old mortar. It is on the wood subfloor... can I get by with this..? Please tell me that is OK.

The tiles I have experience with don't come loose just because the grout (that is between them) is cracked or removed. The bond between the tile, the mortar, and the underlayment should hold the tiles firmly in place. If it was just the lack of support under the tile, I would expect to see broken tiles and you don't mention that.
You need an expert to look at your tile to determine what the problem is.
I am guessing but it sounds like the wrong mortar or bad mortar was used, allowing the tile to move and crack the grout? Or bad grout too?
Was the contractor licensed? In some states the licensing board will follow up on complaints. Some even pay something toward repairs to defective work, done by licensed contractors.
I have done a lot of tile in my homes over the years and I have never seen anything even close to what you are talking about.

I agree withsmearcase about the cracking not be present usually if the floor moves and the mortar has bonded tiles flex and crack there should have been a backer underneath not just the wood . You can get the old mortar up replace mortar an d replace tiles but it makes me curious how many more will come up over time. I think it might be time to have a pro come out and take a look he may see things we cant. I know you have had problems with this contractor that did the original install but I would be screaming to get him back out there and fix the problem. If he's reputable he should be looking at this just to keep his reputation good. I know I would be . I have never and I mean never installed tile directly onto wood Im not sure that's the entire problem though I would like to know why the tiles didn't bond to the mortar properly as smearcase said seems like wrong type or just a bad mix maybe. Let us know what you find out and we will do our best to help just post back with any questions or info. GOOD LUCK, AC

I can't agree more with these two fellas. I would suspect the original guy wasn't up tp snuff in skills. I'd guess from what you have said is he laid the tiles in thinset rather than modified thinset which acts more like glue than concrete. If a few tiles came up in one year you will be facing many more over the next few years since its obvious there is some slight movement in your floor and thinset is brittle.

I did have a professional come out. He said that the whole floor should be redone. I cannot afford that right now. He said I could maybe get a temporary fix with Quartz lock grout. So I bought some of that. However, when I started removing the old grout, it just crumbled away and the tiles lifted right out.
I would love to go after this guy... but he is a loser, drug addict who was working for another contractor who was a neighbor and has since moved away. The guy now works for a manfacturer because he has 5 kids and needed the benefits.

Unfortunately there are a lot of folks out there doing work that is beyond their training or experience. This guy and his boss should not have used the materials they did. Any good pre-mixed stainproof grout will be good to use as a replacement but grout doesn't really hold the tiles all that much. If there is movement or crumbling under the tile even great grout will fail. Good luck, Bob

So what is the best stuff to put down to stick the tiles to?

Wish we had better news for you but no matter what you do now eventually the whole thing will need replacing at some point . New grout may help some but will not hold up over the long haul. GOOD LUCK, AC

AC is correct, over the long haul the floor will continue to fail but we understand your need to try and patch for now. Ceramic on a wood sub floor requires modified thinset, find it in the tile aisle.

Yep, ballenger beat me to it but modified is the way to go you can find it at Lowe's or home depot in the flooring section. GOOD LUCK,AC

Well, now that you know how to do it you can save a bundle.

If you want an easy way to remove the grout and remove the thinset this tool works wonders. C. & E. FEIN GmbH - Der FEIN MULTIMASTER

Look under the "tile" applications section. The tool oscillates rather than rotates and does make minimal dust.

Thanks Guys... the guy at Lowe's recommended Multi Purpose Thinset. What is MODIFIED?
Can we Modify that? Thanks so much for your help.

He recommended it because that's what they have. Multi purpose thinset is OK, if you carefully read the label you'll see it actually is modified.

Sorry I am new to this process. But you have been wonderfully helpful. Thanks so much!

How about liquid nail for a temporary fix?

At this point, I would use a grout remover tool (sold at Home depot or Lowe's) and scrape the grout from the loose tiles. I would just glue or use the modified thin set and relay the ones that came up. Then re-grout and fade it in with the ones that I left.

Since money is an issue, this would get you by for a while. Later, you'll probably need to pull it all up.

I feel your pain. I absolutely refuse to allow anyone to work on anything of mine if I can. I have found that my life time of construction experience gave me more knowledge of many things over the experts. I NEVER put oil in a master cylinder by mistake, or did some of the stupid things I have seen done. I learned to repair compressors after getting them back from the repair shop with the valve heads installed backwards. The only trustworthy person you know is YOU.