Tiles popping. Please help!

[timedpolaris]

About a year and a half ago I had tile put on the floor in my house. We also installed a Warmup electric floor heat system under the tile. The floor came out great and we have had no issues up until about a month ago. We noticed a couple tiles "crunching" when you steped on them and a couple tiles were moving very slightly when you walked on them but only in a couple areas. I called the installer and he came out and he said he would just have to pop out the loose tiles and re-set them. When he took the first tile out, the tiles around it were then loose. He found that a whole section was loose. He took a section of 6-8 tiles out and none of them had any thinset stuck to the back of them. They look like brand new. The thinset on the floor has a few areas that show the pattern that is on the back of the tile, but most of it still has the comb marks from the trowel. If you look at the thinset close there are some hairline cracks in it. The installer says the cracks indicate the floor is flexing and that is what caused the bond to break between the tile and the thinset. In my opinion the tile was never properly set "into" the thinset and it was just bonded on the high spots of the ribs. My house is rather old and it just has a crawl space under it. The original flooring is 1" planks. Before tiling, the installer screwed down plywood over the entire floor-(1/2" I believe). He screwed it every 6". The he thinseted and screwed down the cement backerboard over the plywood. Some of the concrete board was called "Easy Board" and some was called "Weldi-Panels". We then installed the Warmup heat system. Then he thinseted over that and installed the tile. On the first receipt the thinset is called "P151". When he ran out of that he used "LT254-LATICRETE White Thinset". He used "LT1527-LATICRETE sanded grout". After he told me the floor flexing caused this I crawled under the house to look. Under normal walking there is no flex anywhere. If a 200+ lb adult jumps on the floor then there is a slight amount of flex but very very very little. I supported the few areas that were showing flex under jumping conditions with some concrete blocks and now there is no flex even with jumping on it. The installer hasnt been back since he took up the first section of tile. I would like to get some info on this. First, can he just thinset over the old thinset and reset the tiles that are loose in certain sections? Is there a special procedure for thinseting over old thinset? Should a special thinset be used? Is one made for "flexing" conditions? If he cant thinset over the old, how do we go about repairing the floor without ruining the electric heating system? Any other sugestions or help would be greatly apreciated. I dont want to have to worry about this for at least the next 20 years!

[Crestone Tile]

Hi Tim,

The pictures look like you have the best problem to have from an installation error standpoint. I'm not saying there isn't flex in the floor, but the photos show that the thinset was never keyed to the backs of the tiles. Further, the trowel ridges are very evident ... they shouldn't be. The thinset was probably too dry and skinned over before the tile went down.

The trick is to get all of the tiles up that are loose and reset them without damaging the heat wires. To get the tiles on plane with the neighboring tiles, the existing thinset will need to be knocked down with a rubbing brick or such ... pretty hairy over a cable heat system.

Also, run your joists through the deflecto tool in blue bar. Is the plank tongue and groove?

[timedpolaris]

Can he reset them without taking up all the old thinset? What procedure and or products should be used to go over the top of the thinset that is there? The plank is an old tounge and groove. There was some movement in the old planking before he installed the plywood and cement board. I'm not sure what you mean when you say " Also, run your joists through the deflecto tool in blue bar" I really apreciate your input.

[Shawn Prentice]

You need to make sure your floor doesn't "bounce" too much for tile. Take the length of the floor joists, the height and width of the joists, the spacing, and the wood species, then input those numbers into the "Deflecto" at the top. That will show if the floor was originally suitable for tile.

The old thinset will need to be removed before replacing any tiles. Matt's thoughts are right on about the thinset skinning over. The installer should have known that before he set the tiles.

[ceramictec]

Wow, not a speck of thinset bonded to the tile.
Do you know what type of thinset he used?
You could lightly lay a piece of tile on thinset and would have contact.

[jadnashua]

You want enough thinset on the tile so that you get at a minimum of 90% coverage between the floor and tile. You have about maybe 5% because of one of two things (maybe more): (as indicated) the thinset was probably already setting (skinned over) before he placed the tile down, or, the trowel used was too small, there should have been more thinset on the floor in the first place to ensure the tile was then 'smushed' into the thinset to ensure good covereage. The thinset could also have been mixed too dry, or there was a fan running, or the temperature was really high or the humidity was really low. One thing that helps on a larger tile is to spread a thin layer onto the back of the tile (back buttering) before setting it down in the thinset on the floor. This would have ensured a better bond. If the deflection is too high, then the tile would have broken, since it would have been bonded to the floor rather than popping loose since the thinset would have been stronger than the tile. But, with that little coverage, just normal traffic could have eventually popped it loose. the grout helps hold the tile together, so there are likely more tile that are just as loose or could become loose soon.

[Jim Farrell Tiler]

i dissagree with shawn have your tiler remove all the tiles, if those havnt stuck the rest wont be either leave the adhesive on the floor as long as it is stuck down and relay over it

[Shawn Prentice]

Originally Posted by Jim

i dissagree with shawn have your tiler remove all the tiles,

I was talking in terms of a repair...and I wasn't saying that was the solution to the problem, only answering the OP's question.

if those havnt stuck the rest wont be either

That is only speculation and neither of us has enough information about this install to make that determination. It is doubtful the homeowner will get the contractor to agree to take up the whole floor if the rest is deemed to be adhered well.

[Houston Remodeler]

There is a simple test to see how many aren't stuck to the floor. Tap the tiles with your knuckle, sorta like thumping a cantaloupe. If you hear hollowness or feel the tile move (with your second hand while tapping with the first hand) then they are loose. Mark each one with tape. Count those tiles and not their position.

[Jim Farrell Tiler]

shawn i was refering to the removal of the adhesive prior to retiling, you can see the heating cable in one of those pics, obviously the cables wernt covered in FLC if you take out the adhesive you will ruin the heating. The rest of those tiles will pop off the floor with a tap from a bolster lying flat on the floor

[Shawn Prentice]

Originally Posted by Jim

you can see the heating cable in one of those pics, obviously the cables wernt covered in FLC if you take out the adhesive you will ruin the heating.

I noticed that too and it could make repairs difficult at best.

[timedpolaris]

So lets say we get all the loose tiles up and they all look like the ones in the pics. He can then sand down the old thinset being careful not to get into the heating cables then thinset and reset the tiles over it? Will he need a special thinset or any sort of bonding agent? What thinset is recomended for this application? Are there any tricks or special procedures he needs to follow that I should be looking for? I really apreciate everyones input.

[jondon]

So lets say you take all the ones up that are hollow sounding, prolly most of them. If the ones you pulled up show no coverage on the back of the tile, then what is the future of that floor? If he didn't burn any thinset into the back of the tile then most are prolly not bonded.

So you take all the ones not bonded or hollow sounding, how you gonna sand down the thinset in that many tiles without ruining the heating mats? Chances are if there are that many tiles not bonded you got a lot a thinset your gonna be sanding up and don't know how you're gonna sand that much thinset down without ruining the heating mats. Member you new tile gotta be flush to your existing tile, otherwise major lippage. How you gonna remove that much thinset, not ruin any a the mats, and have enough room to put enough thinset down so the tile is bonded good

My thought is if that many are popping up and showing no coverage on the tiles, poppem all up, don't do any sanding, layem all back down cause now they'll all be at the same height, this isssssss assuming most or all of them didn't bond. So that would have to be determined.

Thinset.... a good modified thinset, your choice.

[Hammy]

Having just been to a seminar on ceramic tile failures, that is one of the worst cases Ive seen. It appears everything was done against industry standards. Another way to check for loose and hollow tiles is to take a piece of chain about 18 - 24 inches long, tie a string to one end and drag it across the floor. You will notice a difference in the sound of good and bad tiles.


Hammy

[Houston Remodeler]

if all or most of the tiles can be taken up, the very first thing I would do is get a new tile setter.

Then knock down the thinset a little bit , test the floor warming system, then lay the tiles back over the top