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.
Is it possible to remove tile off Ditra and lay new tile over the extisting Ditra? I used it in my first tile installation attempt with 1″ hex tiles, and while the tiles have adhered well, the grout spacing is pretty uneven. Hex is tricky, and trying to do it at 2 am was… not a good idea.
Can I pull the tile off the Ditra and lay new tile over it?
Hey Brian,
Probably not. You may be able to pop off the hex tile one at a time, but it’s iffy. If you can get it off of there without the ditra coming up then yes, you can go back over it. If the ditra begins to tear or come up then just start over.
I know I typed ‘just’ start over, and I know it isn’t that easy (or cheap), but that’s the option. Sorry.
About a year ago I had a contractor come in and help me put tile down in our kitchen and dining room. It was done in a short time frame and we noticed the grout cracking.
Everything I’d read had said (including you) that this is caused because of floor movement. So I tore up 28 sq feet of tile and it came out way to easily. Then I used a hammer and chisel to chip out the remaining mortar. Before I put the tile down I inspected the cement board, all the screws in the cement board and everything looked good.
At that point I put mortar down, buttered the back of the tile, made sure I got a good seal, waited a day, grouted, waited a day, then cleaned everything up. Unfortunately now there are a few places the grout is cracking…..again! The worst part is that where it was cracking before it isn’t now (barring one area that’s a foot long) and where it wasn’t cracking before it is now! What in the world?!?
My only thought is that I mixed the grout incorrectly? Because if the grout wasn’t cracking there before I don’t see the floor deciding to move after I’ve re-installed tile.
Thoughts?
Hi Marc,
Is there thinset beneath your backerboard?
Unfortunately no there isn’t. When we started it all I mentioned that to the contractor. Both him and the other guy that was with him told me that it would be fine without mortar beneath them. Before the floor was replaced it was vinyl over what I can only guess was put directly onto plywood.
However that doesn’t really explain why there’s grout cracking where it wasn’t cracking before. Where it’s cracking now there wasn’t even a hint of cracking either.
That’s your problem. Removing and replacing tiles can cause movement in the backer and can create voids where there were none if there is no thinset beneath your backer.
Hello,
We had ceramic tile put down about 4 mos ago. The grout began cracking shortly after, but only in the kitchen where they worked one day. The other area, an entry way and hall, are just fine. We know the tile is moving because when you walk on it you get this sandy grinding sound.
It was laid on backerboard and not directly on the plywood. We are getting them back here to take a look at it and fix it. They are implying that the reason is the structural integrity of the plywood. We disagree…we think it was put down incorrectly. What is the best way to make our case?
Thank you,
Jessica
Hi Jessica,
Ask them exactly what they put over the plywood. They likely either didn’t put thinset beneath the backerboard or they don’t have a proper bond between the tile and backer. They probably did not soak the backer before installing thinset and the backer pulled moisture out of the thinset before they got tile over it. If that happens and you don’t backbutter your tile you will not get a proper bond.
Here’s the thing, though, although it’s very likely NOT the ‘integrity of the plywood’ that particular aspect of a tile installation is also their responsibility. So if that is indeed the problem – that is their fault too.
We have vynil flooring in our kitchen,we are putting ceramic tiles over it and have been told we need special grout, can you tell me the name and a supplier please, and do the likes of B&Q sell it. Many thanks Pauline.
Hi Pauline,
If you’re installing over vinyl flooring the grout is the least of your problems. You need to have a proper substrate to bond the tile – vinyl is not one. The easiest way is to install backerboard over the top of the vinyl with thinset beneath it, then screw it down and install your tile over it.
I have no idea what sort of grout may have been suggested to you. It is my opinion that it was likely some sort of flexible grout like urethane to compensate for movement in the installation – which it should not do when properly installed. I have no idea what B&Q is, we don’t have that over here.
Hi – I have a serious problem. I had my cousin, who does hardwood floors personally, installed tiles in kitchen and bathrooms. The tiles were set on plywood that was placed over subfloor. However, the idiot did not screw down the plywood. I fear this will cause the tiles to move and hence crack the grout. Is there a way to cure this with out having to redo everything?
Hi Hoang,
There is no way to fix that without redoing the entire thing. Next time it needs to be installed over a proper substrate as well – bare plywood is not one.
Hi there,
We seem to have cracking tiles all over the house. Limestone tiles in the bathroom cracked on the floor within a year of being put there. The builder did everything he was supposed to do as far as I know but the tiles have cracked in one row all the way along the middle and one brach off to the side onto another tile at the top. We had a leak in the kitchen ceiling so that had to come down and a surveyor said we should put cross struts in to re inforce the beams. I did not see if they were there or not but my brother said they were – he was doing the kitchen. Anyway we want to redo the floor but thinking of putting Amtico in so it won’t crack. Also ceramic tiles in kitchen grout is coming out on two or three of them. And yes my brother did these – bummer eh? I’m thinking of scraping some of the grout out and putting fix and grout in??
Hi Francine,
If your floor grout is cracking in a straight line then something in the substrate was installed incorrectly. If you prefer the LVT then do it. Replacing the grout will not solve the problem, the substrate needs to be built properly.
We are tileing a small bathroom.We screwed down cementboard,didn’t use mortar.Would like to use travertine mosaic mesh tile.Do we seal tiles first?What mortar do we use?Should we use sanded or unsanded grout?Then do we have to cure the grout-I read you spray grout with water for 3days to cure it.Then do we seal all of it??Appreciate any help!!
Hi Nancy,
You may want to read through this: basic tile questions. You need mortar beneath your cement board. You can seal before or after grout, depends on the look you want, the porosity of the tile and the color of grout. Mortar is relative (mostly due to availability). You do not need to spray grout for three days to cure it, it is no longer 1963.
Hi Roger,
I just tiled my second bathroom 3 weeks ago and the grout has some cracks in it. I tiled the other bathroom last June and it looks good. So here’s what I did. I removed the old lenoleum. Scraped the floor down as far as I could to get any loose adhesive cleaned up. Then I screwed the floor at about every 8 ” to make sure it was solid. There was about 3 layers to that floor (plywood, buffalo board, then plywood again) so I was told that it was ok not to use a backer board.
I think that the only thing I did different was that in the first bathroom I put 1/4″ thinset directly onto the floor and then applied the tile with some good pressure to get them set. And when we did this bathroom I cut the tile and the other guy applied thinset to the backside of the tile and set them in place. Don’t know if that matters but that is the only thing that I can see to be different.
So where did I go wrong and how do you suggest that I fix it??
Thanks,
Ryan
Hey Ryan,
I don’t know who told you that it was ok not to use backerboard, but that was incorrect. You need to have a proper substrate to bond the tile to.
If there was not thinset burned into the substrate, or even combed onto the substrate, then you likely have a very poor, if any, bond to the substrate. The tile needs to be removed and at the very least thinset applied to the substrate to reinstall them. Ideally a proper substrate installed for tile bonding as well.
Ok so if I take up the tile how tough is it to get the thinset cleaned up off the sub floor? And by the looks of it, if I install backer board and then the tile, I’m gonna have to cut off the bottom of the door to make enough clearance. And just so I’m on the same page as some of the arcticles I’ve read on here, there isn’t any fixes for the cracked grout..??
Thanks Roger,
Ryan
There are fixes to cracked grout. The fix depends on the reason for the cracking. It is normally either inadequate floor bracing or bonding. With what you’ve described it sounds like incorrect bonding to the substrate. You NEED to have an adequate substrate, whether the door needs to be cut or not. I cut them all the time.
Regardless you need a proper substrate, this will add layers and height to your floor. Products like ditra can minimize it, but it still needs to be adequately supported.
Oh, sorry. The thinset will be difficult to remove if it’s installed correctly. The more incorrectly it’s installed the easier it’ll be to remove.
hi,
this unfortunatly for me is an intresting thred!
i have resentley had my floor tiled throughout my ground floor 50-60sq foot. these are porcaliane 2ft white tiles (looks awesome) well it did. i also have installed electric underfloor heating through out. this has been laid directly on chipboard! arrrh i here you cry! now my problem is movement. i know it all need taking up and starting again but i need an alternative.
My idea! can i remove all/most of the grout and replace with silicon? trying to pump it under the tiles where possible???
what do you think?
thanks in advance
Hey Carl,
There is no alternative which will last. If you use silicone you’ll end up with a huge mess when it separates from the sides of the tile. Silicone is meant to be replaced once it separates, it is not meant to be permanent in any application that is not covered. Once it does that it will begin to trap all sorts of nasty stuff in the grout lines. Pumping it beneath the tiles won’t do any good either, it won’t support anything. Your only viable alternative (which, in all likelyhood won’t last either) is trying urethane grout. It does have some flexibility to it, but I don’t know if it’s approved for use over in-floor radiant heat, you’ll need to check with the manufacturers for that information.
thanks
i will try urethane grout in a small area and give my report.
as my movement in some areas could be 2-3mm i feel i need to put something under for support. my gout lines are very thin 2mm?
this might sound a little CRAZY but what about if i can pump some EXPANDING FOAM under???
as you can see i need help
There should be thinset under there now for support. The fact that your grout is cracking does not mean there is nothing directly under the tile supporting it, it means that somewhere in the layers beneath the tile one or more layers of support are inadequate.
It could be lack of thinset beneath certain areas. If you have hollow spots around the corner or edge of a tile you may be able to put some thinset in a baggie, snip off the very corner of it and tuck it down into the grout line. You can then squeeze thinset into that space with a minimum of mess.
But that isn’t going to solve your problem if the inadequate support is not lack of thinset, and it rarely is. It’s normally lack of proper substrate beneath the thinset layer.
Expanding foam will not support anything in your application. Since you have in-floor heat it may actually pose a fire hazard or, at least, larger problems than you are currently experiencing. The ONLY proper fix for this is to remove what you have, determine the underlying cause of the movement and fix it. Short of that you are simply adding band-aids. Band-aids eventually fall off.
Advice? I know nothing of putting down tile, and I feel that my home developer is talking out his butt telling me that it is normal for my grout to crack at the baseboard only, saying that it is a normal part of my house setteling? Our home is brand new (1 1/2 years old) Along almost all our baseboards our grout is cracking. We have beautiful tile in our bathrooms, kitchen, hallways, and laundry room. I watch way to many DIY shows but do way to few real projects yet I always hear those guy say that your grout should never crack, if it does there is a problem in how it was put down. My home is under full warranty but there is a difference between them coming out and fixing simple cracks and redoing my whole tile. Should I be concerned enough to push for a full redo? Very worried. Please give me some advice if you can. Thank you.
Hi Dawn,
I don’t quite understand what grout you have cracking. Is it grout that is between your tile on the floor and the tile or wood base on the wall? That’s what I’m assuming since you said ‘crack at the baseboard’. If this is the case then the problem is regular seasonal movement. The transition between the horizontal tile and the vertical baseboard is called a change of plane. All changes of plane need to be filled with silicone (ideally) or caulk, not grout. That area is going to move due to regular seasonal movements, wood moves – always. The vertical and horizontal planes will also move in different directions. This is what causes grout to crack in that area. Silicone can stretch and compress to compensate for that movement, grout can not.
If this is the area you mean then just have them remove all the grout there (NOT go over it with silicone) and have them replace it with silicone or caulk. You can get silicone in colors that will match your grout. Also, if this is the area you mean, it’s not a problem. It doesn’t compromise anything structurally at all, it won’t ruin your tile or floors or anything.
You are right I did indeed mean the grout that is right up against the baseboard. It also did not occur till the winter months, even though I live in a warm area, AZ, I am guessing we still get seasonal shifting of the home. The knowledge that wood moves always is not a new concept so that makes sense to me, it is a relief to know that the builder is not just feeding me bs. They have promised to come fix the cracking so I will be diligent to ask what they will be fixing them with and making sure it gets done right. You have helped more then I ever expected! Thank you a thousand times!
about a month ago I installed tile in my in-laws bathroom. The subfloor seemed stable and solid so I installed a waffle backer board directly onto the old vinyl floor. Now they say that there is small horizontal movement in the tile resulting in cracking grout. I’m pretty sure that in adhered the tile to the backer properly but in any case is there a repair short of a complete reinstallation?
Hey Dave,
I have no idea what a ‘waffle backer board’ may be, unless it’s ditra. If it is ditra you may be able to remove the tiles around the crack, cut out the ditra and reinstall a new piece, then reinstall the tile.
First, you are amazing and I wish that I could apprentice with you.
Second, I’ve been reading your other posts. I did use Ditra but skipped the step where I put thin set between the substrate then press it down, instead I used my electric carpet tacker to attach it. It seems that this is where I lit my dog on fire then screwed the pooch. From what the in-laws say the tile is cracking across the the whole bathroom floor (5′ by 6′).
Sounds like a redo?
Yes, complete redo. The mesh on the bottom of the ditra is bonded to the substrate with thinset, this is how it attaches to the floor. Without that you have a free-floating tile floor that will crack and will not last. On the upside – it’ll be easy to remove.
We have had cracking grout with tiles coming up for the whole 6 yrs we had our tile flooring. They replaced tiles twice. It is in 90% of our home and we can’t afford to demo and replace. Can we “glue” the tiles down and regrout? I understand they will crack, but at this point I think cracked tiles would be better than tiles that are, at this point, just sitting on the floor with grout pieces throughout the house. Thoughts??
Hi Kenya,
Yes, you can install them with thinset and they should stay, for a while anyway. And yes, your grout will crack, your tiles may or may not. Depends on the substrate.
What if we actualy used some type of industrial glue then regrouted?
It will crack because the floor moves, not because there is inadequate bond to the floor. If it was metal tile welded to a metal floor that moved the grout would still crack.
Hi,
I have a problem with the ceramic tiles & grouting cracking in my kitchen. This has been an ongoing problem since new. I am not sure what the base material is. What would be the best solution? Replacing the tile or replacing it with laminate planking? I am looking for the most economical way as well. I intend to rent this unit for 1 yr. and the hopefully sell.
Hi Jan,
It depends on how you define economical. If you mean simply short term cost then laminate will be the way to go. A properly constructed substrate and the subsequent installation are by no means cheap. If, however, you mean value then tile, properly installed, will be more than worth it in long-term cost.
To determine the best solution, or the viable solution, you would first need to discover the cause of the cracking. It could be inadequate bonding of the tile to the substrate or it could be an inadequate substrate. More often than not it is the latter, which means more initial cost.
Thank you so much. I am amazed with your quick reply. I intend to at least get an estimate on the laminate flooring.
My husband spent this past weekend laying tile in the entry way. Under it he put a flexible roll of backing, that resembles what you would use to protect a package when you mail it. I did not grout the tile yesterday (he went to work with it in his car). Now the tile has moved, and is very wiggley. He seems to think that if I had grouted, the tile would not be moving. I think he laid the tile wrong, and should not have used a soft, padded backing. What is your opinion? And thank you!
Hi Shara,
I have no idea at all about what product you may be describing. I will say, though, that if the tiles are moving they, or the substrate beneath them, was incorrectly installed. Grout does absolutely nothing to hold tiles in place or stop them from being wiggley. (Great word!)
Hello!
In our kitchen we have 2 grout lines that keep coming out. They are 5’6″ apart and run parallel. I removed one tile and found thinset between the tile and hardiback, and the thinset between hardiback and floor to be very even and believe it has been applied properly. The crack in one area is on the line where the hardiback joins, the crack in the other area is on the support beam. We have 3 large rooms that join that all have this same tile and grout. They are both about 4 1/2 to 5 1/2 feet long. We do not have any other areas with this problem and believe the installer did a good job. Any ideas on what could be causing this? We are thinking of putting down porcelain wood plank tile but are worried we will have the same problem.
Hey Tony,
Is the seam under the one crack, between the two sheets, taped an mudded? Do they have fiberglass mesh tape tying the two sheets together? If not, that’s why that one cracked. If your floor’s deflection is adequate then the likely reason it cracked over the beam is because there is not a second layer of plywood, is there? For a proper floor installation there needs to be a double layer of plywood totaling a minimum of 1 1/8″ with the top layer offset from the bottom to dissipate the stress caused over things like beams.
If you are going to put down plank porcelain you’ll need to build the floor in that manner. Provided it’s done correctly it will eliminate those problems.
Hi Roger!
Thanks for all you advice in this page.
I have 16″ tile installed previous by my occuplation of this home. I have cracking of tile concentrated around an island as well as some crunch tiles also mostly around the island with a few in corners of the room.
My question is, what are possible repairs short of tearing the entire installation up and how long would be potentially last?
Thanks
Hey Jimmy,
Unless you know whether it’s the bond of the tile to the substrate or an inadequate substrate causing it I can’t tell you how to repair it. If it’s the bond of the tile you may be able to just remove the tile and reinstall it. If it’s the substrate then it will all need to be replace. The only way to tell is to remove a tile and see if there is thinset bonded well to both the substrate and tile. If not that’s the problem. If it is bonded well then it’s likely the substrate.
Hi Roger,
Thanks for the quick response. I have had some of the tile repaired. Often tiles will come straight off the floor intact with all the thinset on the tile. There is little or no thinset on the floor. This suggest the bond between the substrate and thinset is bad right?
Is there any way to be sure about quality of the substrate? How is the substrate tested? From the holes in the floor for the registers, there is two layes of wood. They appear to be bottom – 3/4 OSB and top – 1/2 ply. The house is 10 years old and has floor squeaking in various but not noticable bouncy in the tiled area.
Thanks Again
If the tile is installed directly to plywood that’s your problem. If the thinset is only on the tile then it is the bond to the substrate. The substrate being plywood it will expand and contract regularly, this eventually breaks the bond of the thinset. There should be a layer of substrate over the top layer of ply suitable for tile to bond to. This can be cement backerboard or a membrane like ditra, but something else needs to be there.
Hi Roger,
I hear you. I didnt install it and putting tile over ply seems not uncommon.
When you say “eventually breaks the bond”, you mean it will not last as long as it would have with a better substrate and that replacement should be done rather than replair?
I mean it will not last. Eventually, unless installed by very demanding standards and done perfectly, the tile will become unbonded from the plywood. The installation will fail. Yes, the only proper repair would be to install a proper substrate above the plywood layer for the tile.
Roger,
Hello. I had granite tile in my bathroom installed approximately a month ago. I had it installed on the floor, surrounding the tub and as baseboards. The installer used nonsanded grout. While preparing to paint I started noticing holes in the baseboard grout and cracks and holes in the floor grout and the grout around the bathtub. I repaired these places myself and they are not cracking yet. Today I was cleaning the tile to prepare to seal it. I vacuumed the floor with a brush attachment with the vacuum stationary setting on a sheet. After I finished, the spot the vacuum was setting on is now badly cracked. What is wrong with my grout? And what can I do to repair it?
Hi Leann,
If you mean that the tile beneath the vacuum body (not under where you had the end of the hose – the suction end) was cracked then it is not the grout, it’s the bond to the substrate. About the only thing that cracks grout (once it’s cured over 28 days) is movement in the tile. While vacuums do move a little, there’s no way at all that movement should have affected your grout.
Grout does not move, it is not unstable. It’s made from concrete, even unsanded grout. Nearly the only thing that causes that is movement in the tile itself. Do you know how the substrate was prepared and what he set the tile with?
I have no idea what he used. If the tiles are moving, what are possible solutions to the problem?
Well, if it’s a matter of the tile not being properly bonded to the substrate then it’s just taking up the tile (which will come up easily in this case) and reinstalling them correctly. If the tile is bonded well to the substrate then it’s an improperly built or inadequate substrate, which means the entire thing needs to be replaced.
The only way to tell is to actually remove a tile. See how easily it comes up and whether there is thinset on both the back of the tile and the substrate. If not it’s likely the substrate.
Hi Roger,
I have had ongoing issues with grout cracking and tiles making a “creaking” noise when stepped on (even just standing on a tile without stepping can make a noise). The floor is less than a year old and the GC and I have a different opinion as to whether this is normal or an issue. The tiles are 24×24″ and were installed as follows: a dry pack mud bed was installed. The porcelain tile was back buttered with Multibond and installed on the workable mud bed. We agreed to hire an inspector who determined that one of the key issues, among others, is that there are extensive voids in the mud bed. The inspector recommended that can improve the floor by removing the grout and injecting leveling compound with a PSI equal to approximately 2000- 3000 into grout joints before regrouting (and also installing soft joints as there are none). Please let me know if you have any experience with injecting leveling compound to address cracking grout and if you think that this would make a significant improvement in the voids under the tile.
Hey Neil,
Who the hell thinks that’s normal – your contractor? Who chose the inspector? I have never heard of anything like that, and to be honest I don’t think it’ll do any good at all. You may – MAY – be able to fill the voids around the grout lines, but there will still be hollow areas beneath your tiles. How thick is the ‘mud bed’? If it’s less than at least 3/4″ then it isn’t even a mud bed.
Thank you for the advice. The contractor’s position was that the grout issues would be resolved by removing all of the grout and reinstalling it and that the floor was otherwise OK. I believe that the mud bed was about 3/4″ and was placed above sound insulation. We had first hired a different inspector who told us that the floor was not properly bonded and needed to be redone. The contractor then asked the materials manufacturer to inspect the floor and they had concluded that “missing grout happens often in Mud Set installations such as this due to the grout settling into the deep grout joints created by this type of installation.” We then mutually agreed upon this inspector, who made this recommendation to salvage the existing floor and acknowledged that the floor would need to be replaced for it to have a warranty.
Hello! Just found your site and hoping you can answer a few questions for me. I know nothing about floors, tile, or grout and am trying to educate myself. We bought a house and I noticed quite quickly that the grout on the kitchen floor was breaking apart. From the previous owner’s manual on the house the new ceramic tile was installed in May 2004. The invoice lists 1/4 Dens Sheild Underlayment, Tile, Sanded Grout, and Quarter Round. Not sure if the shield underlayment is what you refer to above as Thinset? No idea what quarter round is! I am wondering how long floor grout shoud be expected to last? If longer than 10 years then I’m thinking that the job may have been done improperly. I would call the flooring company to see how they respond if I have a decent expectation that it should last as long. I’m pretty sure the older couple weren’t playing with Pogo Sticks! Is the best option to pull all the tile up and start from scratch? I’ve been told it could be re-grouted but that sounds like a bad idea. If the tiles can be salvaged can they be reused? The kitchen is 300sf but the worst of the cracking covers probably half the area (heavy traffic areas). There is also an attached hall, powder room and laundry of 140sf with the same tile but no problems at all. Can only the problem areas be fixed with a saitsfactory result? Also in the mix is I’m considering just doing wood floors thruout the whole level, especially if it’s too much to fix the tile. I appreciate any thoughts you can offer! Thanks for your time!
Hi Marcie,
Densshield is a topically-faced, gypsum-based substrate used mostly in showers, but is approved for floors as well. The one thing that needs to be done on floors, and doesn’t sound like it was done with yours, is installation of thinset beneath the densshield to fully support it. Being a gypsum-based backer it does not have high dimensional stability in that it won’t support weight if the board is unsupported, it will give and crack. The fact that you see most of the cracking in the heavy traffic areas is indicative of lack of support (thinset) beneath the backerboard (densshield). It is, quite simply, an improper installation.
If the floor is built correctly, and doesn’t move, grout will last as long as the concrete on your driveway. So – forever. It’s a cement-based product and behaves the same. Quarter-round is the rounded piece of wood at the base of your mop boards or baseboards used to cover the perimeter of the installation. Re-grouting will lead to the same problem in short order. The substrate beneath the tile is moving (likely compression as it’s walked on) and replacing the grout will not solve that problem.
If the tile can be removed (HIGHLY unlikely) without cracking or breaking, and the backs are relatively free of stuff (thinset, etc.) then yes, they can be reused. I would not count on that at all. The only viable, long-term solution is to start over. The compromised areas can be redone without the need to do the entire house.
I have a grout line in my master bath that has cracked 5 times since I moved in to a new build about 2 years ago. I think it falls along the expansion joint in the concrete slab my house is sitting on and now I think it’s moving under the shower and causing the hardwood floor in the next room to expand. Any guesses on what is causing this? Thanks Karen
Hi Karen,
Yes, it’s probably over an expansion joint and there is no soft joint in it, they filled it with grout instead. Silicone compensates for movement, grout doesn’t, it cracks instead (but you already knew that…)
I may have missed the answer to my question in here but I had my carpet ripped up and tile laid in my living room and kitchen and laundary room there are patches by my dining room my stairs and a spot in my kitchen where the grout is flaking and popping up and tiles are cracking they laid hardie backer down before they laid the tile if that makes a difference to your answer but they have been out here to replace the tile and the grout a few times I thought it could be my floors but now the kick plate of my stairs is doing the same thing.
Hi Rachell,
It would be my bet that they did not install thinset beneath the backerboard. This causes voids and movement which cracks tile and grout. The only way to fix it is to reinstall the backer with thinset beneath it. Simply replacing the tile and grout will lead to the same problem over and over. (but you already knew that…)
Okay Thank you!!!! I will mention it to them when they come back AGAIN!!!!
Hi Roger,
Thanks for all the good info on this page (and for making me laugh during a frustrating project). We’ve got grout cracking out in a new installation of porcelain floor tile. As much as I’d like to blame it on my toddler and a pogo stick, you helped us figure out the real reason: we didn’t put thinset beneath the backer board. Crap and double crap.
So, my questions are the following:
1. Is there any way to solve this other than re-doing everything? (I’m nearly positive you’ll say “nope!” but I have to ask.)
2. Is it possible to save the tiles (12×24 porcelain) and if so, do you have any suggestions for how to get them up without too much damage?
3. Will removing the floor be any easier if we do it right now rather than waiting a week? (In other words, I know that the grout etc. is still curing; we only put everything in last week. Should we take this out ASAP?)
take care,
Rebecca
Hi Rebecca,
1. Nope. (but you already knew that…)
2. Doubtful. If they were installed correctly and have correct coverage they will come up in pieces.
3. Yes, the sooner you do it the easier it will be. If it’s not yet fully cured you may be able to get the tiles up. Very slim chance, though, if it’s been down for a week.
Hi Roger,
Thanks for the answers! We’re back to sub-floor now, and we were able to save almost all of the tiles. (Thank goodness nothing had fully cured yet. Very patient prying was the technique of the day.)
Now I want to make sure we get this right every step of the way. What’s an ideal subfloor to have under the backerboard? The old subfloor was 3/4″ planks, but I’m thinking that I’ll replace them with 3/4″ plywood in case they were part of the cause of the wobble. Is that enough–would it need to be thicker, or something different?
Thanks again,
Rebecca
Glad to hear you got them up! Beneath your backer you need a minimum of 1 1/8″ double layer of ply. You can replace the 3/4″ with ply, or leave them, then go with 1/2″ on top of that for a very good floor. Install backer with thinset beneath it, then your tile and you’re good to go.
A year ago a contractor replaced my kitchen floor with porcelain tile from a DIY store. A few months ago I noticed that there was cracking and loosening of the grout between two tiles, I also noticed I would hear movement when I stepped on the tiles. Now I noticed that there is cracking and loosening between other tiles. This is all near the center of the kitchen. I do not know what he did as far as if he used backerboard or anything else under the tile. The tile goes under the base cabinets and appliances. What should I do to fix this? Do I need to remove the whole floor or just the center tiles? I think the DIY store still sells the same tiles. I’m trying to avoid replacing the whole floor and all the cost associated with that. Thanks!
Hey John,
What is required to fix it depends on what is causing it. One of the most common causes is cement backerboard with no thinset beneath it. Since it’s in the middle of the floor that would be my guess. In that case the only reliable fix is to remove the tile and backer, place thinset down and replace the backer and tile. You need to start by removing some of the tiles around the cracked grout and see what you have beneath it.
Thanks for the reply. I spoke to the contractor and he assures me that he used thinset between the 3/4″ plywood and the cement backer board that he used. I should mention that this is the top floor of a pre-war building. Nothing is straight or level.
It may be insufficient deflection. Your floor framing is not sturdy enough to prevent the ‘bounce’ that will crack grout. The minimum layering beneath backerboard is a double layer of plywood totaling 1 1/8″. If he only has the single layer of ply beneath the backer then that is part of why the floor is deflecting.
About 3 years ago I had my kitchen / hallway flooring done with porcelain tiles by a contractor. I believe he boarded over my floorboards and then lay the tiles. Now over tile some of the tiles have cracked and the grouting is coming loose in 30-40 %. Now I am not sure if this is:
1) Due to deflection.
2) Badly installed in the first place.
After reading a number of articles do you use cement board or normal ply for these type of tiles, and if so what is my best course of action to get the problem fixed.
Do I remove all tiles and ply install cement board and then screed and then re-tile?.
You help in this matter is much appreciated.
I need to info before I get someone in to have a look so I know what I am talkng about.
Thanks
Hi Gavin,
The problem may be due to both reasons you’ve stated, and/or more. A properly installed floor has two layers of (normally) plywood totalling a minimum of 1 1/8″. Above that you need your tile substrate, this can be cement backerboards or a membrane such as ditra. If it’s cement backerboards it should have thinset beneath it, between the backer and top layer of plywood. The lack of thinset beneath backerboards, or tile bonded directly to bare plywood, are the two most common causes of cracking tile in my experience.
For a proper installation it should be removed and built up with the two plywood layers (the current layers need not be removed if they meet the requirement), either cement backerboard (with thinset beneath it) or a tile underlayment membrane, then the tile reinstalled.
Don’t let anyone tell you they can simply regrout it – that will NOT work.
Roger,
Thanks for the info, another note if I opt to go for ceramic tiles instead do these only need the ply of do they also need to ply etc.
Regards
Gavin.
All tile installations need the same amount of substrate. Ceramic would need the same as porcelain.
Hi , I was searching around and found your great site . My Dad was a tile setter from long ago (old school) He mixed the thin set and also the grout by hand in a Galvanized steel tub .. I used to help him on weekends on his side jobs. Any way ,,my house is 7 years old ,and I have been finding small short worms on my shower floor.They eventually turn into little delta winged flies. After careful examination I have found that they (worms) are coming from small cracks that have developed where the walls meet the floor.I never encountered them before. I think that I will remove all the grout in the corners , dry out the shower and then re grout the floor. do you think that I should remove some of the grout up the wall ? there are no cracks there ,the cracks are only on the floor in the corners that meet the wall. any advice would be greatly appreciated .
J-P an old tile setter’s son …
Hey J-P,
I would remove the grout in the corners, dry it out, then replace the corners with silicone. It’s cracking due to differential movement between the floor and wall. If you regrout it you will have the same problem in about a year. Silicone can compensate for that movement, grout can not.
When my husband and I got married 5 years ago, I moved in to his house that was built in 1955. It was last updated in 1970. I couldn’t stand it anymore and had to redo everything. We did the whole house, but we started with the kitchen. I come from a DIY family and my husband does not. He opted to have someone (who is not tiling anymore if that says anything) tile our kitchen for us instead of letting me do it. We did, however, put the subfloor down and I know it is solid. It is 1″ original lumber laid on a diagonal, then there is 3/4 OSB then there is whatever kind of tile backer and then the tile. The kitchen is 12’x20. There is one crack that goes the entire 20′ length and then three cracks that are perpendicular to the long one. I assume the cracks are along the backer joints. Not being there to see how the tile guy put down the backer. about 8 months after it was originally laid, the tile guy came back and regrouted. He said that we put the tile down too soon after putting down the subfloor and it didn’t have time to settle properly. I find that a bit rediculous. I have regrouted it myself 4 more times. I am so sick of regrouting, I just leave it cracked out. My question is…. can I replace all of the grout with epoxy grout? or will I have the same problem? Thanks
Hi Kala,
What you call a bit ridiculous I would call pure bullshit.
If you replace it with epoxy grout you may not have the same problem (cracking grout), you may have cracking tile instead. But you will have a problem. Epoxy is actually stronger than many ceramics and may crack the tile before the grout comes unbonded from it.
The issue is that your floor is moving. I would be willing to be a HUGE sum of money that there is not thinset beneath your backerboard, that’s what’s casing the movement. It needs to be redone – and I know that wasn’t the answer you wanted. Sorry. There is no way to fix that floor without removing it first.
Thank you for such a quick answer. We have decided to tear it all up and just run the same hardwood that we have in the rest of the house. Yay!!!! more demo!