Replacing tiles

[bazookaman]

All this talk about regrouting a shower has got me thinking out our entry hall. We had the entry hall, the kitchen and the half bath all tiled some times ago. At some point, a couple tiles started loosening. I noticed bits of grout on the floor that had popped out. Then I started noticing the tiles would grind when you stepped on them. Finally they just came up. Didn't even have to pull.

But only in that one spot. That spot is at the bottom of a set of stairs so I guess they would get the most traffic. Anyway, what's the best way to go about fixing this? Am I going to have to grind out all the thinset? Or chisel? Or however? The other problem, Is that I've been unable to find these tiles anywhere. i don't remember where we got them and I can't find any extras. So I cannot break any. That would be bad. Assuming there are a few that pop off, would it be safe to remove the thinset and just redo those?

Any suggestions or opinions? I feel like I've asked this here before but i couldn't remember.

[Michael]

I replaced some tiles in our kitchen right where we stand the most when preparing food, so it's likely the same "most traffic" thing. Mine cracked rather than just coming up, so I had to remove the broken ones without disturbing the others.

I used a grout saw to saw down the grout around the ones that I was going to replace to keep from disturbing the others. I was then able to get a prybar under the edge of the tiles I was going to remove and popped them out. I then used a chisel to get up the thinset from the substrate and to gently chip it off the back of the tiles that hadn't broken. When I replaced them I put new thinset on the floor and also back-buttered the tiles to make sure I had a good bond. It's been a couple of years and so far, so good.

One thing you might want to check (if you can get to it) is the floor at the base of the stairs to make sure there is substantial structure under that part of the floor. If the floor flexes when you hit the landing as you come down the stairs, it doesn't surprise me the tiles came loose. If you can get to the joists under that area, you might want to beef it up right at the base of the stairs to make sure it's not flexing.

[bazookaman]

When I pull the tiles up, they look brand new underneath. NOTHING was sticking to them. They were so nice underneath, they still had the sticker on the bottom. Unfortunately searching for the part number yielded no results. So I definitely don't want to break any.

And there's no chance of getting underneath the floor. Underneath the floor is the basement ceiling.

[Pam]

Maybe put a throw rug on the area after you replace the tiles to help protect them from future damage? A rug would also hide any mismatch with the other tiles.

[mikebw]

If there was no adhesive of any kind that would certainly explain why they came loose. Grout won't really hold them. I think as long as they are sitting on a smooth level surface then there is little chance that they would crack, so just put some thinset underneath and get them back down for good.

[Michael]

bazookaman wrote:
When I pull the tiles up, they look brand new underneath. NOTHING was sticking to them. They were so nice underneath, they still had the sticker on the bottom. Unfortunately searching for the part number yielded no results. So I definitely don't want to break any.

That's why I back-buttered mine. There were big sections of the back of the tiles that didn't have any thinset on them when I pulled them up. So I assumed there was not a good bond resulting in flexing and cracking. I figured back-buttering would resolve that.

[Kraniac]

Tile requires a sturdy floor underneath..it is critical. There are formulas to detrmine the amount of deflection in a floor and whether that floor is capable of holding tile.

How long ago was the tile installed?

The loose tiles is confined to one area?

how big are the tiles?

What are they made of?

If you do decide to reset them..Yes, you'll need to remove all of the thinset.

You can better your chances..or extend the failure time by choosing an expensive, modfied thinset that has a bit more flexibility...Compared to traditional thinset there is a lot of give with these thinsets..but..it may not be enough to solve your issue forever...it's really not what that extra flex is designed for..but it can help.

Is there any way to determine how widely spaced your floor joists are in this area? What the dimensions of your Joists are?

How many layers of subfloor are over them joists?

what are the tiles adhered to? Can you identify the underlayment?

plywood can be ok if prepped the right way, 1x6 subfloor boards (bad, very bad), if you see masonite..never a good sign,

try to do as much digging as you can determine what the structural charasterics of that floor are and you might, at least, get an answer as to why this is happening..

It could be a simple as this..

-the tilesetter used a cheap pre-mixed thinset

-He set tile into an area of thinset that had already begun to set up after he applied it to the floor and before he could get tile on it...ie it skinned over and lost it's initial stick.

Tile applied in very dry weather can also instananeaously suck the moisture out of a thinset mix causing the same problem..this happens

Adhesive issues like this are common with guys who are rushing and trying to put to much thinset down at once..or guys who dont what the fuck they are doing.

In any case..if you clean that area under your loose tiles..dust it wash it with wrung out rag..then reiinstall the tile with a good quality thinset..it'll probably be ok for a little while..

If that thinset seems powdery..flake..not hard the it's either cheap crap or it was a bad mix.

ZERO thinset stuck to the back of tile is a bad sign..skinned over over thinset that dried before the tile hit it..or cheap crap.

There are a ton of factors to consider as to why..people ripping down the stairs and then hitting that area hard at the bottom of the steps is what is causing it..but on a properly designed tile system..it shouldn't happen.

: )

[davester]

I agree with Michael's and Kraniac's solution. It sounds to me like the problem is a bad installation job and/or use of crappy premixed thinset. You need to chisel up that thinset and then put a new layer of thinset down before replacing the tile. I strongly suggest that you protect the edges of the remaining tile with masking tape because when you chisel the thinset fragments tend to fly out and chip the edges of the remaining tiles (ask me how I know). Also, when you reset the tile, use a straightedge to ensure that the tile is flush to the adjacent tiles. If it's not flush pull it up and add or subtract thinset until it is.

[Buzz]

My old WWII Navy neighbor/journeyman bricklayer (R.I.P.) told me his old tile laying trick (about thirty years ago) was to [1] mix in a bonding/flexing agent (a la previous mentions above) with the thinset, and that the best mix in is diluted* aliphatic resin wood glue, and [2] clean the back of the tile really well with acetone, then [3] after the acetone evaporates, lightly spray the back of the tile with a watered down solution** of aliphatic resin wood glue in water before back buttering or placing the tile the thinset bed.

*depends on whether you're using premixed or mix it yourself thinset, but goal is to get aliphatic resin thoroughly mixed throughout the thinset.

**one quick squeeze from the glue bottle into a quart size spray bottle of water, well shaken and allowed to settle before use... solution should still be very watery, and just slightly milky.

davester's taping suggestion should be mandatory for any tile that you actually care about.

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