Your grout is cracking for one reason and one reason only: your tile is moving. That’s it. Okay, that’s not it – Unless your grout is non-sanded and was installed in the last 28 days – your tile is moving. That’s it. Yes, 28 days has significance, it is the amount of time it took my teenage son to clean his room. It is also the amount of time it takes for grout to fully cure.
So let’s figure out why your grout is cracking:
Your grout is newly installed – incorrectly
If you do have grout that was installed within the last 28 days then your grout is not actually cracking – it is shrinking. Either your grout lines are too large for non-sanded grout (smaller than 1/8″) or it was incorrectly mixed. NO! You cannot simply mix up more and fill it in. Read this post about adding more grout to your grout lines.
If your grout is not fresh, well, you need to repair the reason your tile is moving. And stop using your pogo stick in the house. Diagnosing the reason your tile is moving is extremely varied. It could be anything from inadequate deflection in your flooring for the type of tile all the way up to and including the aforementioned pogo stick.
The most likely reasons your tile is moving:
Your tile does not have proper thinset coverage
The most common reason I run into is improper coverage. This simply means that there is not enough thinset beneath your tile to properly adhere it to your substrate and support it. If there are any unsupported areas beneath your tile along the edge or in the corner of the tile, walking on it will eventually work what little support it may have loose and the tile will move down and up every time you step on it. The tile moves, the grout does not. The grout loses the battle and starts to crack out. By ‘crack out’ I don’t mean like that ridiculous Intervention show on cable, I mean it will start to crack and come loose.
To fix this you need to remove and properly reinstall the tile. If it is only one tile it may be an isolated incident in your installation and you will be fine. If you have cracked grout all over your tile installation it was either improperly installed or . . .
Your subfloor is moving
If you have a wooden subfloor and your tile is directly installed to it – go pick out new tile. That is more than likely an improper installation. While tile can be installed directly to plywood it requires a VERY specific method. And I do mean very specific. More than likely it is simply installed improperly probably by someone that did not know any better. If it was properly installed over plywood, well, your grout wouldn’t be cracking. Start reading this paragraph all over. Or . . .
Your backerboard was improperly installed
If you have Hardiebacker, Durock, or any other type of cementious backerboard beneath your tile it should have been installed in the proper manner. It needs to have thinset beneath it, it needs to be screwed down (properly), it needs proper spacing, etc., etc. Read How to Install Backerboards for Floor Tile to see all the things that should have been done.
More than likely there is no thinset beneath your backerboard. Thinset is not used to adhere the backerboards in any way – it is used simply to fill voids beneath the backerboard. It is placed there specifically to prevent your tile from moving. Moving tile leads to cracking grout. But you knew that – or you should start reading this page all over. This would be another time to start shopping for new tile.
Other reasons your tile is moving
You do not have expansion space around the perimeter of your tiled room. No, the tile will not expand – but your walls do. If there is no space between your tile and walls it will force all the pressure into your tile. This will cause cracking grout and, eventually, ‘tenting’ of your tile.
You do not have expansion joints in your tile. For every application there are specific spans of tile which can be installed before a ‘soft joint’ is required. This is simply a grout joint filled with a matching caulk or silicone to allow for movement without cracking your grout or tenting your tile. Most of these measurements are over 25 feet. So in English: if your room is not 25 feet long or wide this is not the reason your grout is cracking.
If your tile is on concrete – directly on concrete – your slab may not have proper expansion joints or the tile installation did not honor those. If installing tile directly to concrete (and you should not) there needs to be a soft joint directly above, or two inches on either side, of the slabs expansion joints. If not your slab will move differently than your tile.
And there could be a host of other, less apparent or less common problems. However, if your grout is cracking it is probably for one of the reasons above. The method of repairing it depends entirely on why it is cracking. Most of it, as with most tile installation problems, is due to improper installation.
Or your pogo stick.
If you have any questions about the proper way to repair your tile or grout just leave a comment. I answer every one of them – really, look around the site. I’m just super cool like that.
Hi Roger –
I have a master bathroom that was “professionally” gutted and remodeled 12 years ago. The original floor was uneven so we had them remove it and replace with a mud floor (second floor of bi-level). The floor tile are 12×12 ceramics. The center tiles (where most of the traffic is) show minor cracks in the grout. I’ve completely removed the grout from the problem tiles and can not detect any movement.
Since I have the last 3 spare tiles in existence I was reluctant to try to lift one to look at the condition of the mud … based on your experience, would there be any merit in carefully/fully re-grouting or is this simply wishful thinking? I have the manufacturer’s latex product to use in place of water and I have the replacement grout and I have fully removed the existing grout..
Alternatively, might there be any benefit in inserting a 3 inch screw into the mud where the tiles meet (before I grout) The grout is about 3/8 inch wide so there would be room to fit a screw with a small head.
Or, should I be looking for new tile and a good tiller to redo the mud and tile?
Thanks so much for taking the time to respond ,
John
Hey John,
The only thing I can think of is that your mudbed isn’t the proper thickness and is cracking. Do you know the height of your mudbed? A screw isn’t going to do anything for a mudbed at all. And a 3/8″ grout line is absolutely huge. The largest I’ve ever actually seen is 1/4″ and that was saltillo (mexican) tile. Although that doesn’t really have anything to do with it, that certainly isn’t helping.
Your mudbed should be a minimum of 1 1/4″ for a full floor – is it that thick? Or maybe 3/4″, depending on your structure.
Hi Roger;
I, too, am a victim of crumbling grout. I just moved into a second floor rental flat that was renovated 2 years ago. I don’t know how soon after the renovation the grout started cracking, but after reading through this post I think I’ve determined that the problem is probably subfloor issues (there seems to be some flex in the floor throughout the flat) and/or improper thinset coverage. I’ve got the telltale crunching noise when stepping on or pushing on a corner of various tiles, and even some barely-visible rocking if you get your eyes down to ground level and push on a corner. It’s a small space; the tiled area (bathroom floor minus tub) is 5.5′ x 4.5′. The tiles are, weirdly, 23.5″ x 23.5″ (I’m in the UK, so maybe this is a mm or cm thing, but the conversions don’t return a logical number either) with 3mm joints. The landlord is unwilling to rip up the floors and do a proper fix. I can’t justify pouring money and sweat into improving his property, especially considering I may only be here a year or two. Regardless, I can’t stand looking at it; every time I’m in the bathroom I spend an extra 10 minutes staring at the grout and fantasizing about various repair options. I’ve come up with two top (and not ideal) contenders: A) Dig out the crumbling grout and replace it with a high quality grout combined with a polymer additive (cut with water at a 1:1 ratio instead of 2:1) and hope for the best. B) Dig out the crumbling grout and replace it with ‘grout calk’ and hope for the best. If this were my own property, or even if I was sure I’d be here a good long while, I’d the tiles up and do it right. But under the circumstances I just can’t.
What’s your advice on which route to take? If either? Any advice or suggestions will be much appreciated. As many others have said, your site rocks. It’s the most informative, well-organized and aesthetically pleasant I’ve encountered in my hours and hours upon hours of research on this topic.
Hi Jessica,
The best option would be to get some very unfavorable information on the landlord and use it to bribe him. Make him do the right thing!
Probably not very feasible, though.
The grout with polymer additive may work. I would actually get some, such as grout boost, which uses no water and just mixes grout and polymer. I do not, however, know how flexible that would make the grout, but it would be more flexible than it currently is. I would not do the caulk thing – it will actually attract and hold dirt, especially on a flooring application over the entire floor. While expansion joints in tile use silicone – that is only one grout line through the entire installation, it’s less of a problem. The whole floor would be a problem.
The larger issue, however, is that the tile is moving. Whether you put flexible grout in there or not, the tile will continue to move. Your tile will likely eventually crack from this. It simply doesn’t have proper support. Maybe once five or six tiles crack the landlord will see his way to do what’s proper.
DEAR ROGER
I INSTALLED CERAMIC FLOOR ABOUT SIX MONTHS AGO I PUT THINSET UNDER BACKER BOARD AND SCREWED THE HECK OUT OF IT I USE PREMIXED THIN SET AND TOLD MY FRIEND NOT TO WALK ON IT AND BEFORE WE CAN GET DO WITH IT MY FRIENDS DAUGTHER HAD WALKED ON ONTHE TILE . I WENT BEHIND HER AND LINE THEM BACK UP I’ VE DO AT LESS TEN CERAMIC FLOORS I NEVER HAD THE PROBLEM WITH THE GROUT POPPING .I NOTICE THAT FOUR TILES WAS BROKEN ,I REMOVED AND RESET THE BROKEND TILE NOW THE TILE DON’T MOVE BUT THE GROUT KEEP POPPING UP I INSTALLED IT CORRECTY BUT THE GROUT KEEP POPPING BACK OUT CAN I USE SOMETHING LIKE COLORED CHAULK NEED HELP
Hi Antwon,
The problem is using the pre-mixed thinset. Pre-mixed should not be used on flooring installations, it will rarely fully cure. If you look on the bucket it likely has a limitation stating ‘not to be used with tiles larger than 8×8 inches square’ or something along those lines. It is not the correct product – it should be thinset. ‘pre-mixed’ thinset is actually mastic with sand in it. Really.
I just laid porcelain tiles with mastic adhesive onto solid cement floor. I waited 2 days then grouted and today noticed a few areas where the grout was separating from tiles..
Any ideas why?
Yup, because you used mastic. Mastic is not approved for floor installation, especially over concrete. Read the bucket – I’m sure somewhere on there it states ‘not to be used with tile over 8″ x 8″ square’ or something along those lines. The mastic between the tile and concrete will likely never fully cure. If you pull one up it will probably still be soft in the center of the tile. Mastic requires air to cure and putting it on concrete and placing a tile over it is just like putting the lid back on the bucket. It’s simply the incorrect product for that application – you need thinset.
Hi Roger–
I did a complete remodel on an old house in Sedona. I pulled the plastic pan out of the guest bathroom, and my contractor and I found water damage behind the shower head. so that entire wall and part of the floor was gutted and rebuilt. (raised foundation)
The problem is primarily the side splash pieces of the shower. I have new tenants at the home, and unless I can fix it, they are going to move out. I will send pictures so you can see. There are also reports that the floor is moving a bit, but none of the grout on shower floor is cracked. Anyway I could use your help and suggestions! At this point functionality is main concern.
Thank you very much, Wendy
Hi Wendy,
I received your pictures but they are really, really tiny. I really can’t tell much from them. I can tell you have cracking between the vertical and horizontal tiles in that one photo. Can you send me larger photos of it as well as some specifics about how the substrate beneath that splash is constructed? Type of backer, waterproofing method, etc. The more details the better.
Hi Roger,
Can not figure out what happened, so I am going to forward the original file as I received it.
The contractor who put this in did a lot of tile work and this is the only problem area. More details to be sent with photos. Thanks!
Hey there. Our shower is about 4ft long and 3ft wide made out of 4″ tiles. Where the floor meets the wall that the shower head is on, there is a ditch that holds water because the floor tile right there is kind of raised like a tent. The tent is the worst in the middle but the change in height is so gradual that it’s created a ditch which stretches the entire length of the 3ft wall that the floor borders. Also, there is a very noticeable grout line that has clearly been touched up in the middle of the width that stretches the full length of the shower. It’s 2 to 3 times the width of the spacing for every other grout line and what’s odd is that it terminates right the worst part of the tenting mentioned above. What sort of thing caused this? How should this be remedied? Any ideas on a cost estimate? Happy to send pictures if needed. Thanks in advance for any assistance you can provide.
Hey Caleb,
90% of the time swelling due to water getting where it shouldn’t causes what you are describing. Pictures would help a lot to try and narrow down what the problem is. You can email them to Roger@FloorElf.com and I’ll take a look to see if I can help.
sent. Thanks.
Hi. My question is a little off topic perhaps and so I understand if you cannot answer. We recently (less than one week ago) had travertine tile installed. The “contractor” used all the proper methods, thinset, backerbackerboad with screws at every hole, then thinset again before laying the tile. It looks good..mostly. There are about three tiles that are uneven. Each tile is level individually, but they are not level across to the next tile and stick up a bit on the corners. We spent over 1k on the tile and supplies so I would hat to just rip it all up, is there anyway to remove and reset just one tile without ruining the whole floor? If so, how? Thanks in advance.
Hi Mary,
What you have there is known as ‘lippage’. You can remove single tiles and replace them if need be. Scrape out the grout all the way around the tile being removed and bust the tile with a hammer. Then pry out the pieces. Once removed you’ll need to scrape the substrate beneath it to remove the thinset left over – do this carefully as to not damage the adjacent tiles. Then place your new tile in there to ensure it sets lower than the surrounding tiles without thinset, if it still sticks up you’ll need to remove more from beneath the area. When it sets lower, pull it up, install thinset, and install the tile level with the surrounding.
A contractor just finished (last week) a walk-in shower in our ensuite bathroom. The floor ’tiles’ are ‘stone’ /pebbles and while everythng looks good after giving the floor 48 hours to ‘set’, the 2nd time we used the shower we found grout cracking and breaking up under our feet. This was not a DIY project and I really can’t offer even a good guess as to why this is happening and the contractor himself is expressing surprise.
I have gone online to see if there is anything special that has to be used as grout with these ‘pebble’ tiles but really don’t have an answer. I’m getting tired of having to get hosed down in the backyard and need to have the ensuite shower working again.
Any suggestions you might have as to cause etc. would be appreciated.
Hey Bob,
Without specific information about how your shower was constructed the only thing I can think of off the top of my head is that the stone pebbles have rounded bottoms rather than flat and there may not have been enough mortar beneath them to support the full load. With rounded stone there needs to be mortar (thinset) under the stone half way up the stone to fully support it. If there are open areas it will create a cantilever effect when the stones are stepped on. That will cause the grout to crack, and shortly thereafter the stones will begin to come loose.
Thanks Roger. Since your reply the contractor has returned twice to remove grout residue and ‘re-grout’ the areas of the floor where the grout had cracked and come loose. Both times there was over 48 hours of drying before shower use but the same areas have once again cracked and are beginning to come apart in pieces. I have provided information to the contractor that I took from your site and other instructional info from other sites but he didn’t give it even a look.
The contractor is not a tiling specialist and my guess is that while he does have skills in drywalling and painting, he hasn’t done much tiling and it shows. Upon closer inspection of the actual shower walls I find that not all tiles have been evenly applied to the walls (more mortar or bonding material used under some tiles than others) and it is very discouraging as we provided him with high quality materials and got an inferior job. My solution at this point is to identify and contract someone who does tiling for a living and pay the (final) price to have the work done correctly. ‘You get what you pay for’ certainly applies to our situation and being a senior it seems that I’ll never learn. Thanks for taking the time to help so many.
Hi Roger! I’m a true novice at tiling in need of some sound advice. I want to ensure that I prepare my foundation as well I possibly can to prevent tenting, grout cracks, etc. My house is about 30 years old, built on concrete slab. I live in Abilene, Texas. We’ve had an extreme drought this summer. The concrete has some cracks that are less than 1/4″ in width. I was advised to use Redgard to put over the cracks. I’m also dealing with adhesive from some old sheet flooring of some sort on the concrete. I was told to get a concrete cleaner to remove it. What are your suggestions to effectively prepare floor?
Hi Jazmyne,
You can use a concrete cleaner but you need to ensure that once it’s done the concrete will soak in water. Just splash some water on it and make sure it doesn’t bead up and sit there. If it does the thinset won’t adhere to it very well. You can also mechanically scarify it if need be which will remove all topical coatings – no matter what it is. Redgard will work fine on the cracks (it was originally designed as a crack-suppression membrane) as long as you have no vertical displacement along the crack – neither side sits higher or lower than the other side of the crack.
Thanks for replying. There is some vertical displacement along the crack according to my level. Will a leveling compound suffice, or do I need to take more drastic measures?
As long as you are talking about 1/16″ or less then a leveling compound MAY work. Keep in mind that vertical displacement is indicative of a larger underlying structural issue, not simply normal expansion and contraction of the concrete. It would be best to get a professional to check the foundation and see if it is a significant issue or something more minor.
Thanks again, Roger. I made a mistake, though. The floor just happens not to be level where the crack is. The cracks is flush. I’ll spare you the explanation of my cognitive dysfunction.
I just had 6-12 x 12 ceramic tiles to pop up with the grout still in place. I used a small screwdriver and started removing the grout today and the six tile was easily removed. I notice a small crack running accross the floor so I figured this is what caused the issue. I dont have any additional tile so i need to reuse the old ones. There is a lot of thinset on the tile. What is the easiest method to clean the backs of these tile off?
HI Steve,
You can try to scrape it off with a 5-in-1 painter’s tool, a chisel, or, if it’s really stuck, a belt sander.
Hi!
We are having a crumbling grout issue. We are not new to installing ceramic tile and have never had an issue before this. The only thing that is different about this installation is that the tile was installed over in floor heating. Could this cause the grout to dry out or cure improperly? I have to replace the grouting but need to know if there is another type of grouting that should be used or what needs to be done differently? We have used the polyblend sanded grout on the installation.
Hey Charlotte,
It can cause problems with the grout if you turned on the heating element within three weeks of installation. After that it won’t effect it at all. One problem a lot of people have with floor heating is getting complete support beneath the tile. How was your floor constructed above the element?
Thank you Roger!
I am sure that the heating was on before three weeks as it was in the fall when it was installed. The type of in floor heating that we have is water and it is installed below the subfloor. I now will have to wait until spring/summer to regrout.
Your help is greatly appreciated.
Roger,
I have begun to pull out the old tiles and the half that is crunching was not adhered to the floor well at all, which is to be expected and of course is easy to remove. However, my question is what is the best way to remove the backer board? Part is screwed down and part is nailed. Do I just use a crow bar with the screws?
Joan
Hi Joan,
If you can it would b easier to use a drill and remove all the screws first. Then use a crowbar and pry up the rest of the backer with the nails. You can use the crowbar with the screws, it’s just more difficult.
Roger
I am a contractor in flint MI I have been doing tile for over 15 years. I did a tile job for a customer about 4 years ago. When we instaled the tile it was a 3 room area we had to do over a couple days to allow the customer to remain in there house. part of the floor was concrete and the other was wood. We installed the cement board over the wood subfloor the first day and laid the tile on the concrete floor. The second day we laid the tile in the other area the customer new he couldnt walk on it for 24 hrs.as we where finishing we where laying the last 3 tiles as we backed out the door my customers mom 92yrs old came walking across the kitchen floor tiles wher going everywhere and she allmost fell. my customer had forgot he had her staying with him for a few days and didnt ell her to stay off the tile.I strightend the tile back out and came back 2 days later and grouted i told my coustomer that the bond of the tile had been broken and he might have cracking tile and or grout. About 3-4 months later he had about 13 tiles that had cracked.I went back at no charge and replaced the tile and re grouted the area. I told them that the kitchen might have to all be redone, she had bought the tile on a clearance and told me she wanted all the tile redone it was over 680sq. ft for all 3 rooms. I located the same tile at a home depot about 60 miles away and went and bought enough to re do the kitchen area sence that was the only area that was wallked on and had cracks. She called me last year and had 8 more cracked tiles, I went out and looked at them and told her i would have to charge her this time to fix the tile.I had put the 240Sq ft of tile in her garage so that she would have it never even charge her for it. Now she is sueing me for the cost to redo all the tile floor, o ya she never even paid me in full for the job we did .I had to hire a lawyerthat wasnt cheap. do you have any sugestions.
Hey Nathan,
What you will be able to prove is unfortunately limited to how much of this you documented and what, if any, contracts and such you have in writing. With that much time elapsed it will likely come down to what she claims and what you can disprove.
I think the best first step would be to have an independent third party inspector come in and find out exactly what caused the remaining 8 tiles to crack. Are you certain it’s due either to the initial broken bond or something else that happened? In other words, bluntly, you absolutely installed the part over the wooden substrate correctly? The floor had proper deflection, you installed thinset beneath the backer, etc.? If so then an independent inspector may be your best bet. If not, for some reason, it may be best to have your lawyer negotiate a settlement of some sort to get it replaced. Ensure that a pre-requirement for following through with that settlement from your end would be that you are first paid for the balance of the initial installation.
If that is unacceptable to her and you don’t have any signed contracts, etc. then that also means SHE doesn’t have any signed contracts. Not certain what the laws in MI regarding contract work but around here (mostly) the maximum required warranty period for most interior finish work (what tile falls under) is, at most, two years. She’s long past that, which means she’s SOL. Basically I would be very nice at first (if you don’t have contracts, etc.) and attempt to find some middle ground with the replacement. If she chooses not to accept that and wants to be ‘one of those’ customers, well, she’s screwed and will probably end up with nothing. Have your lawyer tell her lawyer that and I’m sure they’ll be more than happy to settle if need be.
Start telling your customers what I tell mine – my lawyer can beat up your lawyer.
And from here on out have your lawyer type you up a very basic contract that covers warranty period, etc – basically shit like this, and have every customer sign it. Every one. And don’t feel too bad, every one of us learns that the hard way.
I am having the same problem, crumbling grout. It is only in certain areas of my manufatcured home. I had tile floor in my home, had a water leak and when the new floor was installed i started seeing the grout crumble. They have come out and re grouted the areas that are having problems, but its starting again. the grout only crumbles in a certain area, mainly the center of the home. Is it my house or the installation?
Hi Misty,
It’s likely due to improper installation and substrate. If it’s right in the middle of the home then it is right along the major seam of the house. Manufactured homes tend to use particle board substrates rather than layered plywood. When it gets wet it will swell and disintegrate. This leaves voids beneath your tile in those areas and causes movement. Movement in the tile will cause your grout to crack, come loose, and/or crumble. It’s difficult to give you a more specific answer without specific knowledge of your substrate beneath the tile.
The grout in my bathroom (12 years old) started cracking. My husband says it is because the foundation is cracked. The tile is right in the middle of the bathroom floor. Can we use grout caulk? Will it harden enough so that dirt doesn’t get in there and stick to it?
Thanks!
Hi Christina,
If by ‘grout caulk’ you are referring to color-matched caulk then yes, you can use it. It’s always better to replace the grout entirely in that area, but the caulk can serve as a fix if need be.
Hi Roger,
Great site you have here. Lots of people getting lots of help. Like many others, I have a question about why my grout is cracking…
The tile was installed about 6 months ago and this weekend I noticed some grout around one tile has cracked and is coming out in chunks. Only one tile is moving (you can hear that crunching noise when you push on it) and only in one corner of the tile. However, there are some areas nearby which are starting to show small cracks in the grout where it meets the tile. I imagine they’ll start to shift soon, too.
The tiles were installed using modified thinset. Under the tiles, a 1/4″ cement backerboard was installed on the existing 5/8″ subfloor, also using modified thinset. The backerboard was then screwed down every 6 inches. Prior to installing the backerboard, the subfloor was also screwed down every 6″.
So do you have any thoughts on why the tiles are starting to shift? Research I’ve done points to the thinset under the tiles (improperly mixed or applied). The guy who did the tiles (an experienced home renovator) claims the floor is moving…
Any advice you can offer is greatly appreciated.
Thanks
Dave
Hey Dave,
It could be either one, or a combination of both. Take the 1/4″ backer for instance, that lends absolutely no structural stability to the floor, thinset beneath it or not – it is simply the substrate to which tile can be adhered. So you essentially have a 5/8″ subfloor with tile on top of it, structurally speaking. That’s gonna bounce quite a bit. Once it bounces enough the bond to the tile will eventually be compromised. The minimum allowable wooded substrate thickness beneath backerboard is 1 1/8″ double-layer plywood. You have about 1/2 that. So yes, the floor may be moving BUT it is the responsibility of your tile contractor to ensure your floor meets minimum deflection requirements, with the appropriate number of layers, before installing tile over it. He needs to make sure it’s strong enough to properly support the product he is installing over it.
I am not necessarily saying that he was the one responsible to build it – everyone does it differently. But he is certainly responsible for not ensuring the substrate would support the installation. So he can claim the floor is moving all he wants – he’s likely correct, but it isn’t necessarily moving more than is normal in like structures. It is simply not built correctly to withstand the tile installation intact – that’s his job, to ensure that it is before he installs over it.
It COULD be improperly mixed or applied thinset, but that would likely show signs in various spots all over the installation, or at least in the same end of the bathroom. (Some installers will begin with fresh thinset, then as they move out of the room the thinset gets thicker and begins to cure. This can lead to the outer half of an installation showing signs of problems where the inner half does not.) The tiles connected to the one showing problems may be affected by the one that is moving, it doesn’t really mean that they are compromised.
Hello Roger,
This past week my 12 inch ceramic tiles in the master bath are crunching when walked on. No grout disturbance (yet). The house is 5 years old, built on a slab, in San Antonio, TX. We are in a severe drought. Any thoughts? Thank you very much!
Hey Matt,
If it’s crunching that is likely indicative of the tile breaking loose from the bond in some manner. The crunching is probably the thinset beneath it. If you knock on it does it sound hollow? The heat and humidity you have down there causes concrete to expand and contract – a lot. If the proper thinset was not used it could have been caused by movement in the concrete. To give a more definitive answer I would need to know what, exactly, you have beneath that tile.
Hi Roger,
I recently moved into a house and within the first 3 months we noticed that the tile was beginning to buckle. The tile had been in place for over 7 years before this happened. Finally two pieces of tile popped up like a tent-the grout was still in tack in the middle. When we pulled up the two tiles we noticed a crack that looked like it had been filled in the concerete floor. Now along the same line more and more tiles are beginning to pull up and the tile is pulling away from the grout. Just the other day I also noticed that the tile in the shower by the window is beginning to pull away. We checked around the outside of the house and we can not see any cracks in the foundation. Any ideas?
Hi Stacy,
The good news is the problem is not your foundation. The ‘crack’ you noticed is likely an expansion joint in the concrete. They are placed there because structures expand and contract, they give concrete the room to do that. Your tile is tenting (yes – it’s actually called tenting and when it popped it probably sounded like a gunshot) because there was no soft joint placed into your tile installation. The expansion joint should not be filled with thinset, and the grout line directly above it should have been filled with a flexible caulk or silicone. That way when your concrete moves apart (or together, which is the case in your installation) the flexible joint allows for that by compressing or expanding.
If the tiles along that line are still solid you can scrape out that grout line – all the way to the concrete – and fill it with a flexible sealant. Ideally you should remove both rows of tile over that joint, scrape out the expansion joint, and reinstall the tile with a soft joint (without filling the concrete joint with thinset).
As far as your shower is concerned it is likely simply improper waterproofing and water behind your tile is either causing the substrate to expand and fall apart (drywall or greenboard) or causing the adhesive (mastic) to re-emulsify. I would need much more information about what is behind your shower wall tile to give you any type of solution, though.
Roger,
I have the same problem as Jonathon. I believe they used roofing nails instead of screws to put down the backer board. Do you think this caused some of the problem as well?
Hi Joan,
It’s doubtful the roofing nails themselves have caused the problem. They are actually an approved fastener for backerboards and it’s done all the time with roofing nails (but not by me). It’s likely there is no thinset beneath your backerboards. If the backer is not fully supported screws won’t prevent cracked grout and tile, let alone nails. Also, if the seams aren’t taped and mudded (with thinset) the boards can move independently in different directions which will lead to the same problem.
Roger,
Thanks! So now I need to rip everything out and start over, making sure there is thinset under the backer board, and tape the seams and we should be fine to re-tile.
Love your website! Thanks for all the great information!
You’re very welcome Joan. If you have any questions just let me know.
Roger,
I have finally gotten all the tile, backerboard and most of the thinset removed. How perfect does the floor need to be? I still have some thinset but it seems to be pretty smooth. I have the original plywood floor, it seems to be sturdy, no movement that I can feel. I am planning on using 1/2 in. backerboard, screwing it down, and taping the seams. I really don’t want to add any more height if I don’t need to, so should this be ok?
I am also removing the shower and tub surround. There is a seat/ ledge in the shower that blends into the surround. Originally they used drywall, should I remove all of this around the tub as well and replace with backerboard? If I replace, do i need to use the metal corner bead or just butt the ends?
Thanks for your help!
Joan
Get as much as humanly possible off of it. As long as it’s solid and you place thinset beneath the backerboard as well it should be fine.
You should remove all that in the shower and replace it with backer. You can just butt the seams – corner beads will rust. You’ll also need some type of waterproofing over that, but you already knew that.
Hi Roger,
Couple questions. About six months ago I installed a tile floor in my bathroom (porcelain 12” tile, ¼” gap, laticrete sanded grout, and I put hardibacker board down with thinset and taped the seams). Quite quickly the joints started to crack and now numerous tiles seem to move a bit and make a crunchy sound when I walk on it. Safe to assume I didn’t do something correctly, most likely the floor isn’t stiff enough or I didn’t use enough grout under the tiles.
Was planning on pulling up the tiles and re-tiling with additional grout. First question, is there a way to reuse the tiles if I can get them up intact… meaning, if there is some dry leftover grout on the backside is that ok, or could I just chip as much as I can off? I have a handful left over, but would rather not have to buy all new tile again. Second question, again if there is a little leftover grout on the hardibacker, is that ok? Third question, would it make sense to add another layer of hardibacker to the floor to improve the stiffness of the floor?
Any comments, questions, or suggestions would be helpful. Thanks,
Brant
Hi Brant,
Did you install your tile with grout rather than thinset? That’s what it sound like. If that’s the case – that’s the problem. Grout is not made to adhere tile to anything, it is simply made to fill the areas between the tile. The bond (if any) will eventually come loose and your tile will move. That will crack your grout. You need to use thinset. Is that the problem?
Hi there,
Almost a year ago, my wife and I renovated our kitchen within an old wood framed building. Now a few of the porcelain floor tiles down the middle of the kitchen are moving. I believe the unsanded grout was mixed poorly as well – very loose and watery when applied. Prior to the installation of the porcelain tiles, I had the GC sister the floor joists since everything was sagging, then applied CDX plywood followed by a layer of hardiebacker.We used a Flexbond mortar. Rather than removing the tiles that are moving, should I inject an adhesive between the grout lines to eliminate the movement, then regrout with a sanded grout (grout joint is 1/16″)?
Hey Peter,
That won’t last. Did you put thinset beneath the backerboard? If not, that is likely why the grout is cracking. If the floor was sagging it is likely that the backerboard does not have full support under all of it. I imagine it was sagging right beneath where the current movement is? If so – that’s likely the problem.
Hi Roger,
I installed tile in my 2 upstairs bathrooms about 16 months ago. Initially the grout was pulling away from tiles in straight lines in 4 separate areas of both bathrooms within a couple of months. In talking with several people including yourself I came to the conclusion that I improperly mixed the grout as I added more water to the mixture as it began to harden. Obviously I should have done more research before I took on my first tile job. Now I have noticed 2 tiles, 1 in each bathroom that are loose, they make crunching noise when I step on them. The bathrooms are small and in talking with the “floor experts” at Home Depot
they told me if I fastened backer board with screws I would not need to apply thin set beneath the it as my bathrooms are small and it would not make a difference, so I didn’t. In reading all the posts it sounds as though this may be the problem. I live in a 2 story townhouse, and this winter I had a problem with the foundation as we had allot of snow which kept melting and refreezing as there was not proper drainage. There was noticeable movement in the walls that was parallel to the front of the house where the drainage problem existed. The flooring in my bedroom which leads to the bathroom has buckled in several spots. So my question is, is it possible this movement in the foundation has contributed to the tiles starting to come loose or would it be the lack of thin set under the backer board and my lack of experience.
Hey Shawn,
It’s likely a combination of both. However, if your floor buckled in the bedroom, using thinset beneath the backer may not have made a difference. The excess stress on the flooring substrate and walls probably caused the bond to release in those areas. You may be able to simply remove those tiles and reinstall them with fresh thinset, but those also may not be the only tiles affected – the others may not yet be noticeable. I would try that first, then if you have more problems down the road you may want to just start over and use thinset beneath your backer. And stop taking advice from the guys at HD – but you already knew that.
I have a crack in my tile floor. I know the problem. I had an addition put on my house. The builder built the addition 1/2″ lower than my existing subfloor. When I tiled my floor I used different thicknesses of backer board to even things out. I did not think about the fact that I couldn’t stagger the seam. If I would have put a soft grout line there I would be OK. Or any grout line for that matter. But I didn’t, it cracked 3″ from the edge. Now as the seasons change the crack shrinks and grows. I was wondering if there may be a way to ‘float’ the tile so it can move. I thought about steel plate under the tile. Maybe attached to one side and float to the first grout line. HELP!!
Hey Warren,
Your best bet would be to remove that row of tile and install a crack-suppression membrane of some sort. That will allow in-plane movement when the substrate expands and contract. Then install your tile and place a soft joint at both grout lines on each side of that row. It would be best to do that during the time of year that the crack is widest apart. That way it will compress the soft joint as it moves rather than pulling it apart.
We installed a tile floor in our kitchen two years ago. Within the last month are grout has been cracking in random spots, it cracks when you walk on those spots of the tile. I feel that is properly installed, ie we installed the backerboard to our plywood subfloor with thinset and screwed the backer board down. We installed the 16×16 tile with thinset, grouted and then sealed the entire floor. This tile is a porcelain tile.
This is extremely upsetting considering the money and time we just spent installing this brand new floor. We have had no sitting water on our tile and I am also unaware of any foundation issues.
Any suggestions or thoughts?
Thanks
Hi Janae,
If I can figure out why it’s doing that I’ll need certain specifics, so I’ll be asking you a load of seemingly irrelevant questions, and some that are not so irrelevent. The first being: Do you remember what kind of thinset you used? Specifically? Did you mix it ‘wet’ (runny) or ‘dry’ (stiff)? Did you mix it all up at once and tile or did you mix smaller batches that stayed essentially the same consistency until it was gone?
The reason I ask these is because, from what you describe, it sounds as if the substrate was installed properly – although you did not mention taping and mudding the backerboard seams – it sounds like a thinset or deflection issue. Do you know what the deflection of your flooring joists is? (Is your floor ‘bouncy’ when you hop on it?) And most importantly, did you install an additional layer of plywood over the existing 3/4″ (5/8″?) plywood?
We used Laticrete (brand) Mega Bond Thin –Set Mortar. We mixed it so it was a little runnier than peanut butter. In total we probably mixed up four batches while we tiled the entire room. The room is about 15×16. We did not tape or mud the backerboard seams. We did not install an additional layer of plywood over the existing plywood. We didn’t do this because we were trying to keep the tile as even with the hardwood floor in the adjoining room. Not sure how to answer the flooring joist question. We have a ranch with a crawl. I guess you could say the floor is slightly bouncy.
Hope this helps. If need be I can pop one of the tiles up where the grout has cracked badly and send a picture. Thanks for your help.
Well, the lack of a second layer of plywood is an issue. Although you said ‘random’ cracks I’ll bet that the distance in inches between the worst areas can be divided by 16 (assuming your floor joists are 16″ apart). In other words, the areas where the floor joists meet the subfloor are likely the worst areas of cracking. What I think is happening is the single layer of plywood does not shore up your floor stiffly enough to have tile not move over the top of it. As you walk on the floor in the areas between the joists it causes deflection (downward movement). This places direct pressure on the areas of tile directly over the joist. Uneven movement = cracked grout. A second layer of plywood with the seams offset distributes this deflection over a wider area as well as simply making your floor more sturdy.
Now, if you have access to your crawl space where the joists are you can place stringers between the joists about every 12″ or so glued and screwed to the existing joists. This should shore up the floor enough to eliminate, or at least minimize, the movement. While not an ideal solution (yes – that would be replacing the tile and fixing the floor) it should work. This assumes that the individual tiles have not begun to come loose, that it is only cracking grout. If they have begun to come loose then one of them would likely eventually crack as it was walked upon or you would hear ‘crunchy’ noises as you walked in there. If that isn’t the case then installing the stringers and regrouting the floor should take care of the problem.
Hi,
I moved into a new house in June last year. In the middle of the bathroom 3 floor tiles running from the front of the toilet bowl across to just before the door have a hairline crack running straight through them which has then started chipping and flaking on the surface. Importantly none of the grout has cracked either between the cracked tiles or around them. I also think the approximately 1in strip of cracked off tile in each case has now lifted slightly proud of surrounding tiles at its edge. The builder says it is not their issue and that the floor cannot have moved or be the issue because the grout would have gone before the tile. He says the only way a tile itself would crack was if i’d dropped something on it.
Personally I fail to see how an impact could have cracked 3 tiles in a straight line. In my head I think the crack occurs across a break in the flooring below and the levels aren’t quite right which has cause a gap under the middle of the tiles and caused them to sag into it – but the builder says that can’t have happened due to the unmarked grout.
Hey Anthony,
Well, your builder is full of shit.
Normally the grout will give way first. However, if there is full coverage of thinset beneath your tile and it is solidly adhered to the substrate then the stress will divulge on one specific point or line in the assembly without cracking the grout. What I think is causing it is the crack is directly over a seam in the backerboard which, in turn, does not have thinset installed beneath it. When the floor joists expand (and they will) the individual sheets of backer will move independently if not fully supported with the seams taped and mudded.
The easiest way to prove him incorrect (and me correct) without tearing out those tiles is simply to remove your toilet and look at the tile and substrate beneath. I’m almost positive that there will be a seam that runs directly beneath that crack, there will be no mesh tape and thinset over the seam, and the backerboard beneath will not have any thinset under it. That is simply incorrect installation – and it is his issue.
My wife and I recently bought a new home that was built in 2007. We noticed a few months after we had moved in that the floor would make a cracking sound when walked on, only in certain spots. Not long after, the grout started coming up in chunks. We have put it off so long, that now the entire floor is doing this a little at a time. Some of the tiles are so bad that they sort of teeter back and forth. I haven’t tried doing anything yet and I’m kinda wondering if I should. Should I get professional help? Does this sound like bad grout, bad thinset, uneven floor, incorrectly installed tile altogether,…….? What would you suggest?
Hey Jonathon,
It sounds like an incorrectly prepared substrate (no thinset under the backerboard – if there is backerboard) or incomplete / inadequate thinset coverage. Since your tiles are moving I would opt for the latter. If there is complete coverage on 1/2 of the tile, walking on the other half will eventually compromise the bond of the 1/2 that is adhered. The grout is not the problem – it is simply giving out due to movement of the tile. Grout isn’t built to move. Pop a screwdriver under one or two of those tiles and see what you have going on there. You can send me a picture of it at Roger@FloorElf.com and I’ll see if I can tell you exactly what the problem may be.
On the up side – the tile will be easily removed.
Hi Danielle,
If the issues are in your substrates, and it sounds like they are, then at the very least the tile will need to be removed, the subfloor PROPERLY repaired and supported, then the tile reinstalled. There should be absolutely no (noticeable) movement in any substrate beneath a tile installation. There also should not be grout in the corners or any change of plane as you’ve described – it should be silicone or caulk. Those places will almost always crack if grouted. But it sounds as if the issues with your installation go deeper than that. You may be better off having a professional (a different/real professional
) come and take a look at it to see what will be required to properly repair it.