First off, I'm sure you're right in that they didn't apply enough adhesive, just from your description. But let me assure you-- even if enough mastic HAD been used, the floor would most likely have failed anyway, because of the fact that mastic was used. TEC DD is probably the strongest mastic around, and it's still not recommended for floor use for two reasons, only one of which sounds like it would apply to you, and that is that it's water emulsive, meaning even after it's long since been installed, and the mastic has dried, moisture will re-soften it up. This is why it's only recommended for dry walls, with tiles smaller in size than 8x8's.

Secondly, there is no adhesive, thinset, or epoxy that will adhere tile to OSB. I'll bet you can probably take a spatula, and the rest of that floor will come right up. I know you said you can't afford to do the floor right at this point, but you need to start squirreling away your nickels and dimes because it won't be too long before you don't have a choice. You might try, for now, putting them back down with more DD mastic. It won't hold for too long, and the tile will most likely sit a little proud, being there's two layers of mastic under it, but I wouldn't want you removing the mastic that's there now, or you'll be taking up a whole lot MORE of the floor. I'm telling you-- you need to get ready to replace that floor, soon.

Our PO was a shortcut flipper. When we looked at the house I'd seen cement board in the kitchen floor (solid as a rock) through the vent hole (thank God) but hadn't had access to the bathroom floor structure until I saw the OSB and I can see the pine floor (that runs through the house) through a plumbing hole in the cabinet).

I was only able to remove about 3 square feet of the tile with my fingers, the rest I was not able to pry up (I'm sure I could have GOTTEN them up if I needed to, but I don't want to pull up more than is necessary). The TEC DD was spread WAY too thinly in that area, as I pried away from that area (and the tiles became increasingly difficult to pull up) the adhesive was thicker and I could see a molding of the words on the back of the tile. I think that some of the tile wasn't even touching the adhesive. The rest of the floor "seems" much more solid than this area was...

Is DD mastic the best thing to use for this repair? The bucket the PO left is dried up, so I will be purchasing new anyway. When you say "soon," how long do you mean? We are planning a complete gutting, which would happen about 3 years from now when I will get my Master's degree and be able to financially contribute to the household again.

Would I be able to save the tile from this install and recycle them? This was nice tile and should have lasted half a century, it's a shame that it might have to go to a landlord because the "flipper" flopped. I know that the Octagon/Dot style will be hard to install correctly without the netting, but I bet it would be a better install without the netting anyway. The PO left about 20 square feet of tile.

I really appreciate your help, Bill.

I don't know if these repairs will last three years, but they might last long enough to be able to put together a couple hundred dollars and DIY this. It's not that tough an evolution, and I can walk you through it.

Bill, a question about care: :-)

1) I wouldn't use anything rubber backed unless it's taken up off the floor immediately after using the bath or shower. The reason is that it'll hold moisture IN as well as it'll keep it out.

2) That would be my recommendation.

3) I wouldn't bother with it. Like they say-- you don't polish a rusty grill.

OK. I would love your advice--if this can be done RIGHT for a few hundred dollars I'm game. I had thought it would be closer to a thousand.

This is what I would do...

Get you a tube of PL Premium urethane adhesive.

a little dab and push them hard into the mesh backing, so it flattens the dab, and a little squeezes out the edges. Use mineral spirits to clean any adhesive immediately.

Let them set for a whole day, then grout.

Floorguy-- wanna do 3 sq. ft. MINIMUM of 2" octagon and dots a tile at a time? Especially when there's a good chance the rest of the floor's about to pop?

kterlep-- He's right, though-- the urethane adhesive would work better as a temp fix, if that's the route you want to take.

let me ask you-- what's the square footage of your bathroom floor?

Hi Bill,

Would urethane adhesive come up later? I don't want to make a bigger mess if I'm going to have to demo it.

There is about 100 square feet of tile. I know it would be laborious to put all the tiles back individually, I was thinking I could quickly put together a "jig" of sorts so that I could tape the tiles together on the front and make a new 1' mosaic tile.

I know it isn't a perfect fix, but it will last longer then you might think...

When I bought my house, I had some loose tiles. Didn't have time to completely redo it. I stuck the 5 or 6 tiles back down with liquid nails of all things, just to get us in the house, and I would fix it right later. It is still later 12 years now, and I have not needed to fix it. It is still holding tight.

kterlep-- Before I get you all excited about doing this, go ahead and get prices on what the tile you want will cost you per foot, and then I can give you a more accurate figure on what it'll cost you overall.

Hi Bill, I would probably replace the tile with a similar mosaic tile (whether 1 inch hex, or basket weave, or octagon & dot) , and looking at the prices on Home Depot, it looks like they run from about $4-$10 a square foot. I realize there are probably better places to find it.

Maybe, but they won't be much cheaper, if at all.

Figure about 300.00 plus the cost of the tile. That would include Ditra, 4 thinset, and additive to mix the thinset with for under the Ditra.