Flooring and Carpeting Loose tile, electric radiant heat, backer board

Flooring and Carpeting Loose tile, electric radiant heat, backer board

Flooring and Carpeting /Loose tile



QUESTION: We built a new house (5/8″ plywood subfloors, 16″ OC)last year and had experienced installer tile kitchen, mudroom, foyer and half bath with 12″ tile in July. Central air installed in mid-August. Moved in Labor Day. Over the winter I noticed a «crackling» sound from tile where kitchen meets foyer (high traffic), now seems to be spreading past pantry/basement doors, also 1 spot in foyer near floor register, and also middle of half bath (it’s only 3’x7′). Installer used my 1/4″ Hardibacker over subfloor, I provided screws and helped screw down part of kitchen but I can see ring nails at top of basement steps (he didn’t run backer board all the way to edge, and tile ends before edge of backer, so I have to finish off that spot). He didn’t put glue under backer, and he used thinset not mortar to set tiles since I have electric radiant heat in part of kitchen, instructions said to use thinset.

I can’t tell from your key test, but are these tiles loose? Grout is starting to crack around 1 corner of 1 tile in doorway, otherwise looks OK. Would it be possible to pull up tile from carpeted edge and replace noisy tiles? I have extra.

Also when we moved in I thought I felt 1 tile at edge of cabinet move, but grout isn’t cracking. Is that loose? What’s solution for that tile and others not abutting carpet?


ANSWER: Thank you for your question Sheila,

In the text of your question you say «He didn’t put glue under backer, and he used «thinset» not «mortar» to set the tiles since I have electric radiant heat in part of the kitchen». I suspect that what you meant to say was he used «mortar» instead of «thinset» over the floor to install the tile. If what I said is what you really meant then you have a failed floor on your hands because «mortar» is not an approved adhesive to install tile with. The crunching sound you are hearing is the broken bond mortar that is now being crushed into a fine sand currently beneath your tile. I suspect that if you were to take a shopvac and small screwdriver and work at the loose grout for a minute that once you removed the grout that you could easily tap the tile right up. The key test is a layman’s method of determining any tiles that have broken bond in comparison to say, and adjacent tile that is «still bonded» so the tone change is easily discernable. if you aren’t hearing this easily discernable difference I’m afraid that it’s telling me that there are no currently bonded tiles. The Hardy backer board should have had at least some PL-400 to help it stabilize to the subfloor but even without the construction adhesive the screws should have held the underlayment securely enough so what I’m sensing here is the the adhesive for the tile is your culprit for failure. Mortar is fine to set brick and block even Flagstone on a patio but it simply will not serve as a proper adhesive for tile. Where you are hearing this crackling sound is where I want you to concentrate your efforts in regards to using the shopvac and small screwdriver to remove the loose grout, I’ll be willing to bet that once you remove the first tile that there will be several others that will come right up behind it. Try this and come back in a few days (I put myself on vacation to have time to answer all the questions I get before I get buried with a bunch more) and let me know what you discover and we’ll go from there, ok? I’ll wait.

Perry V.

QUESTION: We’ve been playing phone tag, the last message from installer said it sounded «structural, since it’s been 9 months». I had a GC (not my builder) look at subfloor (tile is on first floor over full basement), he said the floor is not moving at all, 3/4″ T&G plywood is glued to 2×10 joists, problem is tile installation. Screws are not close enough together, the spot near the DW where I feel it moving is not screwed at all (last 1 ft of tile butting up to cabinets). He also looked in opening for floor register where tile is so loose I can pull it up with my fingers, he broke off a piece of adhesive and crumbled it in his fingers. It’s white — he believes it’s mastic, not thinset. Is there a good way to tell the difference? Installer’s estimate/contract said that he would supply «thinset». If he used mastic instead, the GC said eventually all my tile would come loose — it’s loose now because not enough adhesive around edges of foyer, but kitchen floor is «crunching» because in high-traffic area we’ve broken the bond and this stuff is grinding underneath, as you said.

How can I prove the installer used the wrong stuff/installed it improperly? We’re looking at probably $10,000 to rip up and replace 400-500 sf of (discontinued) tile, not to mention having to move out all mu appliances and stay out of the house for a week. GC says this is too big for small claims — I’ve called my insurance company. Thanks

Flooring and Carpeting Loose tile, electric radiant heat, backer board

ANSWER: Hey Sheila,

Well. Mastic would have been a huge «no-no» and visually it is very easy to tell one from the other. Of course the easiest way is to simply pull up a piece that is already loose and visually inspect the underside. Mastic will peal right off thinset will hold tightly if a mortar was used it will just rub off. Mastic will be shiny and smooth where it came in contact with something and dried and you can probably just flick it off with just your finger. Typically Mastic won’t make a «crunching» noise as it doesn’t have any sand in it. If you want to make a determination as to the proper install you can go one of two ways. One is to hire a Home Inspector to come in and make a determination that will be officially documented and can be used for a court decision, or similarly you can have a licensed and insured third party Tile Contractor to do essentially the same thing who can also testify to the same in a court decision. Most small claims court cases are usually limited to $600.00-700.00 maximum so this indeed is outside of that consideration. Let me know how this all turns out Sheila.

QUESTION: The GC swears it’s mastic, but will try to get his tile guy out. I pulled out 5 tiles last night (didn’t even scrape grout out b/c it was cracked) — with my bare hands! It came up whole, only a little adhesive stuck on a few places, there is lots on the floor. It’s not shiny. I read mastic will disintegrate in water, put a piece in cup, it didn’t dissolve but did get softer so that when I rubbed wet piece between my fingers it kinda smeared — but a gritty feel, not sticky. I can break pieces right off the tile and break the trowel ridges off the floor (but can’t get it totally off, when break ridge off there is still white underneath stuck to Hardi), but it doesn’t peel. Improperly mixed/premixed thinset? Don’t think it’s mortar. BTW, homeowner’s doesn’t cover improper installation. I can send pics if you have a way to get them.


Hey Sheila,

Something just popped into my head as I had an experience with a friend of mine. He lives in a small mountain community and needed to get some thinset adhesive (I asked him to get some) so I could help him remodel his bathroom. He went to a local «2nd tier» Home Improvement Center. you know the type. and purchased what was labeled «pre-mixed» thinset and it came in a 3.5 gallon bucket. He brought this material home and didn’t give it another thought till I arrived and asked him where the bag of thinset was so I could get started. He lead me to the «bucket». well thinset simply does NOT come in a bucket. Mastic does. but sure enough the labeling on the bucket did indeed say «pre-mixed» thinset so I opened up the bucket and everything «looked» like Mastic, until I reached in with my finger and scooped out some and rubbed it together with my fingers. It felt «sandy» yet felt like Mastic as well. Well the material was in truth a Mastic that had sand added to it touting the material as a «pre-mixed» thinset. It was no such thing. I suggested that he return the product or use it for a door stop but I wasn’t going to use it to install tile on a floor. It was a dreadful material and supposedly was designed to be «user friendly» as it was already mixed up and ready to use. I have a creeping suspicion this is what you have on your floor as the adhesive. You don’t have to source «your» insurance, you should have a copy of «his» insurance as that would have been something you would have asked for prior to this guy starting the installation. If you don’t have it now would be a good time to suggest he come over and give you a copy which will give him adequate encouragement to try and resolve your problems, and quickly. Let me know how this turns out Sheila.

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