When there is a significant amount of movement on the substrate of a tiled floor or wall it may lead to grout cracking. When this happens it will leave what looks like a crack in the grout where it has come away from the tile. Unless your grout was installed very recently this is always due to movement in the tile. If your grout is new it may be caused by incorrectly mixed grout. With grout that has been doing this for a while it may lead to whole chunks of grout coming loose and leaving large voids in your grout lines.
While it may be tempting to simply mix up some more grout and fill these voids you need to know that it will not last. If you do this it will fill the grout lines just like new but over time will lead to the same problem. Grout over grout is not a permanent solution.
Why it won’t last
The first reason is that when you go over the top of grout that is already cured with new grout, there is no adhesion to the old grout. It will instead simply create a layer of grout on top of the old grout. These layers have no way of sticking to each other. When you grout tile the grout actually sticks to the sides of the tile rather than whatever substrate is beneath it. While it will stick to the substrate at the bottom of the grout lines to an extent, it is not a permanent bond. Attempting to grout over the top of old grout is simply stacking two seperate layers of grout. It will always remain two seperate layers.
The second reason is no matter how much of the old grout you may take out to install new, if you do not fix the actual reason the grout failed in the first place, eventually the same thing will happen again. As with any problem you may encounter with a tile installation, you must figure out the initial cause and fix it to prevent repeated problems. This is an involved process which I will cover in a different article. For now I’ll stick with the solution for the grout problem.
What to do
Rather than simply filling the grout line where the grout is missing, you must remove the old grout at least 2/3 the depth of the tile so the new grout has a feasible surface to grab onto. The easiest way to do this is with a grout saw. Ideally you would remove the old grout all the way to the substrate before regrouting it, but 2/3 will be sufficient if it is difficult to remove.
You need to remove any of the old grout that seems loose or has come loose from the sides of the tile. You also need to make sure the spot where the new grout butts against the old is a 90 degree angle, or close to it. In other words from the top of the grout line straight down. You do not want a slope. Eventually a slope must be feathered to a very thin edge. That will be the first place it will fail again, any very thin layer. A 90 degree angle prevents that.
It is also better to make the transition from old grout to new in the middle of a grout line rather than at one of the corners of the tile. The grout line at the corner of the tile has six different spots it can fail, the middle of a grout line has only one. It lessens the chance of failure.
After you remove the sufficient amount of the old grout just mix some new grout and fill the lines. You must make sure you force the new grout into the grout lines very well. You want to make certain there are no voids and the lines are full.
The above method will work to temporarily fix your cracking grout. As I pointed out above, you must find the initial reason for the grout failure before a permanent fix will last. It’s difficult to say how long this fix will work, it may be two weeks, it may last a year. That depends on the severity of the problem that caused it. It also depends on the application (wall or floor) and how much use it gets. A floor in your main entryway will not last as long as a shower that is never used.
You should also take into consideration the age of the grout. If you are repairing grout that has been installed for five years, the new grout, even if it is the same brand and color, will not likely match perfectly. The best solution, of course, would be to fix the cause of the cracking and regrout the entire floor. Depending on what you’re fixing and why this method may solve your problem.
Roger,
I tiled my shower walls 3 or 4 years ago and have noticed hairline fractures recently in the grout. Is it possible that these fractures in grout would crop up years after grouting due to improperly mixed grout or is it more likely movement in the wall?
Thanks.
Hey Mac,
It’s likely movement in the wall. After 28 days that grout has done everything it’s going to do, after that the only thing affecting it will come from something else.
I am in the process of remodeling my bathroom and have recently tiled and grouted the floor and tub/shower surround. The grout that I selected (it was the pre-mixed type) is just too dark and I really don’t like it. There is a lighter color available that I would like to use. Since my installation has been done within a 3 week time period, would it be possible for me to just cover the current grout with the new? I would appreciate any assistance you could offer. Thank you!!
Hi Terri,
You need to remove the grout that is currently in there. The grout adheres to the sides of the tile in the grout lines – with grout currently installed it will not be able to do that. It may stick to the face of the current grout but it will likely not last long-term.
Hi Roger,
oops! :-) Wow, you are fast! Thanks so much for your response. Although it certainly wasn’t the answer I wanted to hear, I do want to do this the right way, so, I guess I will have to get busy digging out the old grout!
Hi Roger I hope you can help! Had a guy re-tile the bottom part of my shower where I was having some leaking due to incorrect tub installed for shower use. He got that problem fixed but he re tiled and said wait 3 days but I was unaware he was supposed to come back and seal it – he said he told me it needed sealed – any how I showered after the third day and now I have a mess. grout is oosing between the tiles. I did try cleaning it up and re grouting and sealing to no avail. I hate to have the job done again what can I do to fix it. He used a gout and cement produt for small jobs.
thanks so much CHeryl
Hi Cheryl, please pardon the coming rant, it isn’t aimed at you…
How in the hell is grout oozing??? The only product I can think of that would do that would be pre-mixed grout. Urethane grouts take a long time to cure in certain applications but they do not need to be sealed. I’m not sure what you mean when you type “g(r)out and cement product for small jobs”??? So if it is a urethane grout your contractor apparently isn’t familiar with them, and if it isn’t urethane-based (pre-mixed) it shouldn’t be used in a shower. The only real viable options in that scenario would be epoxy or regular cementitious grout (powder mixed with water).
Part II
Sealer makes things stainproof – THAT’S IT. That’s all it does. So the short version is I don’t know what he’s used nor why he needs to seal it to prevent it from oozing. Not real sure what you have going on there. If you could send a picture to Roger@FloorElf.com I can take a look and see if I can tell what’s going on.
Hi Roger
I appreciate your rant believe me what I have been through with this
bathroom is worth ranting. The product he used is by Tec Invision it’s
called Adhesive and grout it’s for small jobs and repairs. It is premixed
and sanded and says ready to use. I cleaned out the ooosing grout yesterday
before thinking to take a picture (sorry) Used a spatula for dry wall and a
rag to wipe it up and went in between the tiles as much as I could to remove
this stuff.
Your suggestion of what to do now would be appreciated. My thought was to
remove as much of this stuff as possible ( it did hold the tile in) and
then use regular grout as you suggested.
I can’t tell you how much I appreciate your quick response,
Thanks you,
Cheryl
I’d just use regular sanded grout and grout it up. FYI – I just checked the data sheets for that product, it states right there that it is not for use in showers as well as stating that sealer is not needed for the grout aspect. Just as I suspected – it’s hi-tech mastic.
Depending on the size of your tiles you may want to pull them out and replace them with regular thinset – this product is not suitable for tiles over 8×8 inches square – just like mastic. That part is entirely up to you. You can read the data sheet here: http://www.tecinvision.com/pdfs/datasheets/PDS_Sanded_Adh&Grout_042610.pdf
Me and my Husband decided to DIY our small 1/2 bath. Everything has went Okay until yesterday we grouted the 12 X 12 Porcelin tiles. After we finished we left for the weekend. When I returned home I notice that the Grout has dark streaks in it. The dark areas look the same color as the grout did when it was wet but it is dry. I think I understand by reading the posts that we either didnt mix the grout good or we got it to wet while cleaning off excess. What should I do now. Do they make some type of product you can put on grout to make it a uniform color. I havent sealed it yet. Thank You.
Hi Tammy,
Can you scratch the very top surface of the lighter areas and see if it is the darker color? If it is then the problem is due to too much water either in the mix or while cleaning. If that is the case you may be able to lightly scrub the grout with white vinegar and water or use a drywall sanding sponge very lightly over it to try and get to the darker areas. If it does not show the darker color under the scratching then it is probably from inconsistent mixing of the grout. Was the grout polyblend from HD by chance? If so it is probably the first solution – that stuff is horrible with water.
They do make grout colorant. You can google it or you may be able to find it where you purchased the grout. It is, however, essentially a stain or paint for your grout lines intended to change the grout color. But if you can get the colorant in the color it’s supposed to be it should work for you.
I may not have described this correctly, the color the tile should be is the light color. I looks like it has this dark color marbelized in it. But you are correct if I rub on those dark areas i can get to the correct color. I just didnt think i should do that. Could I get that acid stuff and use it to bring off that top color. Thank You
Yup, It’s called sulfamic acid and should take care of it for you. You can find it at most big box stores in the tile section. I would try the vinegar and water scrub first – that will likely take care of it. If that doesn’t work the sulfamic acid is the next step.
Thank You! Ill let you know how it works out. Thanks Again!
Hi Roger,
I recently had a bathroom remodeled. The wall tiles in the tub surround area have a crackle finish that had to be sealed before grouting. My installer said he used three coats of the penetrating sealer before it stopped absorbing the product. I don’t know how long he waited in between coats or how long he waited before grouting. There are areas where the grout has obviously absorbed into the cracks in the tile, mainly located in the tiles near the ceiling. The biggest problem is that the job was grouted on Monday and today is Wednesday. There are areas of dark grout and light grout. I have been waiting for the grout to cure so that I could apply the final layers of sealer. I was planning to do this after 72 hours cure time. The variations in the grout shades are extremely noticeable as the darker areas look like the grout is still wet. I am so disappointed. The tile was very expensive. There is a mosaic band of linear tile that is a mixture of glass and marble that he sealed as well. I was planning to seal the marble with a marble sealer and not the penetrating sealer used on the ceramic tiles. The grout used was an unsanded Laticrete product. I called the guy I’ve been dealing with at the tile store and he immediately gave me the phone number for Laticrete. I haven’t heard back from them yet. I believe the grout will have to be removed and the job regrouted. I don’t have the box from the grout to know the lot#, so I am cautious of only removing the dark grout and replacing with a newly mixed batch. I am very concerned about chipping the glaze off of the ceramic as the grout is removed. I’m afraid of having the same guys correct the problem. One more thing, the bathroom floor tile (a porcelain product) was grouted Monday as well, and there are areas that need more grout (the same problem is evident on the walls, around the window, etc.) Is it too late to add grout to the floor tile?
Hi Kirsten,
Yes, it is to late to simply add more tile to the grout. The new layer will initially look fine, but will end up chipping off a little at a time. It sounds as if the grout job was simply done poorly as well as incomplete sealing of the wall tile before grouting. The lighter areas may be due to using too much water when cleaning the grout or incorrectly mixing the grout with too much water. The whole thing may need to be regrouted but you should wait to see what laticrete says. They will also likely be able to tell you the best way to clean out the tiles which were incorrectly or incompletely sealed.
Hello Again Roger,
Thanks for your previous reply. Due to the number of errors in the grout application, my husband and I determined to remove the grout and regrout. I have almost completed removing the Laticrete non-sanded grout from my new crackle-finished ceramic tile tub surround install. I would like to wipe down the tile with a damp cloth to remove any remaining grout haze and then use sulfamic acid to try to get grout out of a few areas that hadn’t been properly sealed and grout seeped into. Then I will reseal the tile before grouting. Is this an acceptable order of doing things? After reading the info you have on your website I would like to use the Laticrete SpectraLOCK grout. Can you lead me to a great grouting tutorial (book, or website) for a do-it-yourselfer, or if that is not advisable(doing it myself, I have never grouted before) can you recommend a way to find an expert in the field like yourself? I’m willing to pay, I just don’t want to have to remove the grout again!!!!!
Hey Kirsten,
Yes, that is the correct order. I really don’t know of any grouting tutorials but if you follow the directions of the spectralock you should be just fine. And when they say you have 80 minutes of working time – they mean 80 minutes. After that it is basically a colored rock in your bucket.
Just mix up small batches at a time and take your time. If you can find a pro that will grout only that’s always a better option, but it’s hard to find someone that will only do that. What part of the country are you in? I may know someone in your area if I knew where you were.
Thanks, Roger. I would rather have a pro put in the grout, but how do I know if they’re ‘really’ a pro? I live in the Tampa, Florida area.
Hey Kirsten,
Give Brian from Ceramictec a call. You may have to wait a bit, I’m unsure what his schedule looks like currently, but he is a professional and him or any of his guys will take care of you very well.
Thank you Roger!
We are having our bathroom tub wall redone. the guy i hired tiled the wall and the other day stopped by to grout. He spread grout all over the tiles and then left and told my husband it could stay on there for 24 hours. I have never heard of leaving grout on without cleaning your grout lines, he just spread it all over and left. well, after a few hours my husband panicked and went in and started cleaning off the tiles with the sponge and water but that grout is sealed and the grout lines look like crap. can that be fixed? have you ever heard of such a thing? I was always told you had to do you grout lines real soon after you apply the grout if you want even lines. I am very upset, this was very expensive tile and he had made it look like crap, and when I called him on it he acted like he does this all the time. I don’t believe that grout would of come off those tiles if my husband hadn’t went and wiped it off. I think it would of been hard as a rock, he is coming back monday, he did the grout thursday. would love to know what you think!
Never heard of a technique where grout is left on the tile for 24 hours – ever. Do you know what type of grout he used? Specifically – which brand? That is not a proper installation technique with any grouts that I’m familiar with (most). Anyone can act like they do something all the time. What brand of grout did he use?
Tec Accucolor sanded grout, the color is black (actual name Raven), i bought through and through black tiles very expensive. I can see where he missed many spots that don’t have grout in it. He said he could fix it, that he uses fine steel wool and he also called the tile store and he is bringing some sort of chemical, not sure what it is. I think he knows he messed up. The grout lines look terrible. So, I take it that my husband was right in getting in there and getting that stuff off the tiles? it probably would of been worse. thank you though, i knew grout can’t be just left on. I am so disappointed in this project and the bathroom isn’t finished yet. He has alot to do and I don’t know if he can do it.
If you are unhappy with the given results of your grout give him a chance to fix it on Monday. Make sure he knows that you will be inspecting the work BEFORE he leaves. Inspect every square inch of that assembly, and I do mean every square inch. If you are unhappy with any of it make him fix that part. Become anal about it! If he does not fix the entire shower to your satisfaction then boot his ass out the door and get someone that knows what they’re doing.
The bottom line is that you are paying for a service – why would you pay for something you are not 100% satisfied with? You shouldn’t. If your project is beyond his capabilities then you need someone that knows how to do it correctly. Leaving accucolor on tile for more than an hour or so is an absolute sign of inexperience with at least that product. It has very specific installation instructions RIGHT ON THE BAG! Inexperience aside, he should at least be able to read – no?
Do not accept, nor pay for, something you are not satisfied with – period.
Thank you Roger, I will do just that. You made me feel better, I needed reassurance that I knew what I was talking about, he made me doubt myself. I will see if he can fix it. thanks again……
Roger, in pursuit of some tile literacy today I’ve found my way here. Last week we had our tub and shower remodeled. The evening after the work my wife and I could see fine-lined cracking throughout the grout application. I think this falls under the grout (MAPEI, Ultraflex 1) being incorrectly mixed which you mentioned in the lead paragraph. The contracting agent dispatched the same person out to “make the job right.” The remedial step was to apply a second coating of grout over the first coat. When I pressed the agent and craftsman on the quality of the craftwork, all three of us standing in front of the job, they insisted, staking their reputations and expertise, that I ought not worry about its integrity because it was common on new jobs to see such cracking, and, it was “standard industry practice” on new jobs to fix this by “skim coating” the grout. When I asked how often cracking occurred in grout applications like mine, they estimated 20 to 30 percent of the time. The agent refused my request for any extended written warranty for craftsmanship only on the grout application.
So, I’m wondering how this story squares. Did I experience standard industry practice, in which case I have no worries about the work, or something else entirely?
Jeff Crunk,
Austin, TX
Hi Jeff,
It is not common to see such cracking nor is it common or standard industry practice to ‘fix’ anything – correctly mixed and installed grout does not need fixing. 20 to 30 percent is, to me, a ludicrous figure. It’s happened to me once and it was my fault, and it was because I mixed the grout incorrectly.
With all that said, it can and does happen from time to time. I live in Northern Colorado so really dry air or low humidity, extreme heat, most of the climate or temperature issues that lead to problem with grout properly curing are not issues here for the most part like they would be in, say, Texas.
Skimming the grout with fresh grout, provided they were only hairline cracks, should resolve the problem. If, after two or three weeks, cracks begin to appear again it may be indicative of a larger problem caused, mainly, by movement in the substrate. If it still looks good in a month you should be fine. I know that’s not an immediate solution but there isn’t anything significant to worry about at present from what you’ve described.
Hi Roger,
I just finished grouting my bathroom tub surround and the grout is very uneven (dah!)
It has been a couple of hours..can I add more grout in the spaces I missed or will the grout not adhere? It looks awful the way it is. The tile themselves are not overly even either. I don’t want it to set if I can fix it now somehow. Some of us just shouldn’t try DIY. Any comments will be greatly appreciated.
Hey Bob,
If it has only been a couple of hours you may be fine adding more grout to it. It would be better to simply scrape out those areas first with a screwdriver or something similar and re-install the grout. You have to mix it up anyway and that will guarantee the grout will adhere and last.
Hi Roger,
thanks for all your comments, I was able to narrow down the problem in my bathroom shower. I have experienced grout cracking for several weeks, before using the shower.
It turns out the mortar bed may be uneven. I had put down a kerdi shower pan. I believe I simply
mudded too much mortar above the pan, which may not have dried completely, before tiling. The shower floor still had some movement days after preparing, and before tiling.
In digging up a number of the grout lines (the shower spans 4 by 3 and the area with the most cracking is mostly in the center near the drain), I saw some movement in the small 1 by 1 tiles. I was able to rock them back and forth with my fingers.
I fear you are going to tell me to take up the entire shower pan. I certainly do not want to attempt to life up the mortar and redo. Presuming you agree with my diagnosis, is there a way I can effectively DRY the mortar bed, so there is no further movement and then re-tile? If you disagree with my diagnosis and/or approach can you give me your thoughts?
Thank you!
Hey Julia,
I seriously doubt you would be able to dry the mortar out. I’m assuming you used a modified mortar beneath the pan? It should have been unmodified due to the requirement of modifieds needing air to fully cure. If it is modified beneath the pan that is likely your problem. It will never fully cure beneath that product. Unmodifieds cure strictly through a chemical process – no air needed. If the movement is around the drain that is indicative of uncured mortar beneath it – that’s right in the center.
1×1 tiles are a bit small to try and set around a kerdi drain without first skimming and leveling out the ‘dip’ around the drain. 2×2 tiles are a pain, I can’t imagine 1/4 that size. (Yes, 1×1 tiles are 1/4 the size of 2×2’s). I also believe schluter doesn’t like tiles less than 2×2 over their pans – I could be incorrect about that, though, I don’t use them. The smaller the tile, however, the larger the point load being placed on any particular area beneath a tile. In other words if you place 100 lbs. on a 2×2 tile the point load would be 25lbs/square inch. On a 1×1 it would be 100lbs./square inch. Multiplying your stresses on a given product by four is rarely a good idea.
If your mortar is too thick and there is movement it is likely cracking, which leads to more movement. You DO NOT want movement around that drain – it may eventually compromise the waterproofing or the drain itself. Bottom line is you need to find out exactly how the movement is occuring, or why it began. If it began as a result of movement beneath the pan then it needs to come out. If it is simply a mortar problem above the pan and above the kerdi you may be able to repair it provided you do not compromise the membrane on top of the pan and there is no movement in the pan itself.
Hello Roger,
thanks for your response. I just discovered the “unmodified” issue a few minutes ago. I mistakenly told you 1 by 1. They are 2 by 2s. But I certainly understand the weight issue.
So I understand I have two options:
1) Lift the pan
2) Lift the tile above the kerdi membrane.
Can you suggest what you would feel is a more appropriate tile size to work with the Kerdi drain and slope towards the drain?
Do you have any additional advice on how I can be really careful as I lift the tile?
Thanks again.
Hey Julia,
I would start by removing those loose tiles you mentioned. From there get something thin like a putty knife and CAREFULLY wedge it between the very bottom of the tile and the mortar. You want to sheer it off of the mortar. after that you can lightly tap the remaining mortar with a hammer (LIGHTLY, DAMNIT!) to chip it apart until you get down to your membrane. See if you can check for movement in the base without having to remove all the mortar from the membrane. If properly installed it will rip the fleece right off of the kerdi. If it is solid at that point simply try to reinstall the tile and give it plenty of time to cure. If there is movement it is below the pan and there is really no way to resolve that from above the pan.
2×2’s are fine on the shower floor – I use them all the time. No problems with that aspect at all.
Hello Roger,
I am on it, thank you. I will let you know how things progress in the next few days.
Julia
Hi Roger,
I have read all the great advice you have been giving about the tile grouting. I too have a problem and wanted to ask your opinion. My contractor just finished redoing my bathroom. I have put heated floor under the tile. When he tiled the floor after one day (before he grooved) I placed pressure on some of the tiles because I needed to get something on the side of the bathroom. Since the glue was not dry yet, he was able to re- align the tiles. Of note, it took a very long time ( a week) for the glue to dry). When he grouted the tiles, all the grout has been cracking in the main walking area, he regrouted again and same thing. I am not happy about this, obviously. My contractor is a very competent and honest guy and he told be the readjusts grout is breaking is because I placed pressure on the tiles which broke the glue (there is also still unevenness on a couple of the tiles).
My questions are:
1. could the grouted be breaking because of what he is saying
2. Could the grout be breaking because there is too much flexing due to the floor heating and not properly preparing the floor for this kind of. Installation
3. Is it possible to to only remove the tiles that are not holding the grout and re-install ( re- glue) them
4. would it be better to caulk instead of grout?
5. Any other suggestions other than redoing the whole floor?
Thank you in advance for your help.
Ferj
Hi Teri,
1. Doubtful, although not impossible
2. Yes, improper substrate preparation / incorrect products used to install are the likely reasons
3. Yes, but it will likely happen again, so not a long-term solution
4. no, never
5. Not really
With all that out of the way my concerns with what you’ve described derive mainly from the description of the ‘glue’ used to install the tile. The only acceptable product to install tile over radiant heating would be powdered thinset which is mixed with water – which will cure in a MAXIMUM of 48 hours under normal conditions. Now stating that you stepped on some before it was cured it is very possible that you did break the bond of those particular tiles. However, if he simply ‘readjusted’ the tile that was incorrect. The tile should have been lifted, cleaned (as well as the substrate) and reinstalled with fresh thinset.
But I don’t think he used thinset. I think he used mastic. Or ‘pre-mixed thinset’ which is mastic with sand in it. Was it pre-mixed in a bucket? If so then it is simply the wrong product. That garbage is not rated for tile over radiant heating – in my opinion it shouldn’t even be rated for floors. If the grout is breaking loose it is due to movement – period. Movement means your substrate was improperly prepared and/or the incorrect setting product was used. If it ‘took a week to dry’ then you either live in an igloo or it was simply the wrong stuff. Either way it needs to be replaced utilizing proper substrate preparation as well as the correct setting materials. It doesn’t make anyone less honest or competent – it may mean he is simply unfamiliar with this particular type of installation and did it incorrectly.
Hi Roger,
You helped me once before with a redgard question I had (I will send you a picture of the finished shower once I re-do the caulking…I learned that I despise TEC Accucolor caulking). Anyway, thanks for that, and now for my next question, which I am posting here because I don’t know where else to post it.
So, I tiled my kitchen backsplash with white subway tiles on mastic and grouted with TEC Accucolor (I think it has some additives for flexibility or something). Anyway, now that I’m using my kitchen, I think the upper cabinet above my work space is too low–I keep hitting it with my knife when I move food to the stove. I would like to replace that cabinet with a 30″, but if I move it, I will need to re-do the backsplash there. That would entail removing about 10 partial tiles, tiling the empty area, and re-grouting. So my questions are:
1. Can I/ how do I remove the tiles and mastic?
2. Apparently, different amounts of water in the grout mix create different colors in the end product. Is this a really visible difference? I don’t want it to look like a patch.
Thanks so much! Your website is the best and I tell all my friends and family about it!
Hey Valerie,
Yes you can remove the tiles. The easiest way is to remove that cabinet first so that you can get a thin blade similar to a putty knife or drywall knife between the wall and tile. Place the blade there and gently tap on the handle to wedge it in there. Just keep tapping it down to the point you need to remove the tile. You can place a piece of tape on the drywall knife to gauge where to stop, usually 1 or 2 tiles at a time. Rinse and repeat ’til you get them all out of there.
The ideal situation with the grout is to use the same grout you used the first time, provided you have some left over. If not just be sure to get the same brand and color (but you already knew that) With subway tiles and the small grout lines normally used any color difference, unless it is completely out of whack, will hardly be noticeable at first then as the grout ages it will blend in better and better. A small amount of water one way or the other rarely leads to significant color changes on smaller installations. Most of the warnings concern very large installations where you would be using multiple bags or boxes of grout and tying in the grout installation at several different areas. I think you’ll be just fine.
Thanks for telling everybody! Now git to work!
Hi Roger,
I had on old shower upstairs redone by a “professional” with 20+ years experience. The problem is that for some reason he didn’t use his helpers and did it himself. Apart from being a disater in every way and not measuring properly, forcing me to buy a new shower frame (all the glass and metal), he also made a backward leaning bench where water collects everytime. This in addition to the fact that that tiles aren’t even, some are so close that there’s very little grout between them others have about 1/3 of an inch of grout between them. And to top it all off, he must not have mixed the grout well. I’ve hade water collecting then dripping in the kitchen ever since. He came back and epoxyed the grout which seemed to work for about 3 days. He’s old and claims to be broke as well his sister is dying from cancer so I can’t and won’t wait on him because I’m afraid to see what he’ll do next. Is there anything I can do to even cover the wholre tile if that would help without having to take out the shower and everything?
Thanks
JC
Hey John,
If the shower is leaking it is simply improperly built. There is nothing you can do with the tile or grout to make it waterproof. The shower should be completely waterproof before one piece of tile is installed. I would have a true professional come in to rebuild it and have him document absolutely everything in that shower. Depending on your local codes and laws you may have grounds to have your last ‘contractor’ foot the bill.
You really should stop using that shower until it is rebuilt if at all possible. The water you see dripping in the kitchen is only the visible damage being done. It is normally exponentially greater in the wall cavity where you can’t see it.
Roger,
Thanks a lot. Great advice. You’ve confirmed what I’ve been suspecting.
As you pointed out, though, right now I need to focus my energy and money getting the shower redone properly then sue the incompetent installer.
JC
Hi Roger
I have some small crappy areas of grout that is porous and like a credit card thickness shallow. Can I wet the area and make up some wetish grout and go over the top to make a nicer appearance. Thanks
No cracks, just a poor job. Is still new with no sealer.
Hey Porky,
Nope, the grout won’t stick. You need to scrape the current grout out of there away from the sides of the tile. The grout sticks to the sides of the tile – not anything beneath it.
We have a large walk-in shower that was tiled by the previous owners roughly 2 to 3 years ago. The shower has a bench and somehow water has gotten into the grout near the front lip of the bench and caused it to crack, i.e. between the bull nose and the first row of tiles. I’ve removed all the grout but a lot of the mortar underneath the front edge of these tiles is soft and has crumbled.
The tile work itself still seems solid which is the good news, i.e. none of the tiles are loose. I am just debating whether I should try and get any cement down into these deeper cracks before I go ahead and regrout all of the affected areas and if so what kind of cement and technique I should use.
I believe part of the problem to be that instead of using one solid piece or slab of stone they tiled the bench seat with smaller tiles. I also suspect that they didn’t do a good enough job at forcing the grout down in between the tiles and they may not have mixed the grout just right. Water has been pooling on the bench and even though all of the tiles and grout lines were sealed, water has somehow gotten into the tile work.
Everything looks to be sealed with tile and grout sealer so I’m a little puzzled as to how this happened so quickly given that this work was only done a few years ago. Any advice you can provide would be of help. My inclination is just to fill it in with grout, seal it all again and see how it goes. If we get the same problem again in a few years we’ll have to look at redoing part or all of the tile work around the bench.
Regards,
Rob
Hi Rob,
We need to first start with some very basic (well, to tile guys anyway) things.
First: Sealer does not waterproof anything. It is necessary to assist in cleaning and prevent the grout from becoming stained. That’s it – it doesn’t waterproof.
Second: Thinset (mortar) does not become soft when subjected to water. Mastic does, thinset doesn’t, it is a cement-based product and will not soften.
Third: Tile and grout are not waterproof. The shower should be entirely waterproofed before a box of tile is opened. Grout does not assist nor compromise the waterproofing at all. You should be able to scrape out all the grout in the entire shower and soak it down and, if properly built, it will not affect your shower at all.
Given the last point it really doesn’t matter whether one piece of slab was used or one-inch mosaics – doesn’t change the waterproofness of your bench at all. And, given this point, they could have forced the grout into the lines with a steam roller and it wouldn’t change what it’s currently doing.
From what you are describing it sounds to me like there are a couple of different things going on. The tile may have been set with mastic, which is becoming soft because it is being subjected to water (is it white or dull gray?). It also sounds like the bench was not properly sloped (pooling). And most importantly it sounds like the shower was not properly waterproofed, at least around the bench.
9 times out of 10 (literally, probably more than that) when there is cracking of grout on the edge of a bench or curb at the change of plane – where you are describing – it is due to swelling. This means that water has penetrated into wood and it has begun to swell and press against the tile – the first thing to go is the grout – it’s the weakest link. Filling it with grout and sealing it will not fix the problem. It may slow it down to some extent but water will continue to wick into whatever wood it has come in contact with behind the tile and continue to swell. At the very least the tile and whatever substrate is present should be removed from the bench and rebuilt by properly waterproofing it so water cannot reach the studs or framing.
If you download my shower waterproofing manual (it’s free) it will explain how waterproofing a shower works. If you have any questions please don’t hesitate to ask.
Thanks for your advice. The tile and bullnose corner was set with something grey … it doesn’t appear to be mastic which I’ve used before.
So if I understand you correctly, water is getting in under the bench from somewhere else other than where the grout first started to crack? In other words, I likely have a leak somewhere else in the system or even a slow leak in the plumbing?
The bench does have a slope (side to side and not front to back) but the tiles were laid somewhat unevenly so you get small pockets of water pooling here and there.
I will be carefully reviewing your installation guide.
Thanks again.
Rob
you were right … it is white so it appears to be mastic which I gather is not the right product for this application. So even if the grout and sealant were applied correctly, moisture is still going to get underneath the tile and if mastic is used I guess this is the problem that you get.
Using mastic will cause the adhesion of the tile to the substrate to be compromised and, if the tile is moving, will cause the grout to crack. If the tile is not moving (it is still solid) it is due to movement, likely caused by swelling.
No matter which product you use to install your tile, no matter which sealer, no matter which grout – water will get behind your tile and grout.
Hey Rob,
If your grout is cracking after 2-3 years is has nothing to do with the grout, it’s due to movement in some form. In a shower it is almost always caused by swelling from water getting into wood. Once water comes into contact with wood, the wood will actually ‘wick’ it just like a candle.
The source of the water may not be from one specific source, but water is getting to the wood from somewhere. There is either one specific spot where the waterproofing has been compromised or the waterproofing was done incorrectly. Water will get behind the tile and grout – that’s never a problem. The entire substrate must be waterproofed to prevent it from getting any further into the wall cavity and to the studs or framing. Somewhere in that bench that is what is happening. It could very well be in the front of that bench where the grout is cracking – but it is not due to the grout cracking – that’s the aftermath. KnowWhatIMean?
Ive been redoing my whole bathroom for the last several weeks. I’ve installed a broken pattern with 13 1/8 inch tiles on 1/4 inch grout lines. I grouted two walls last night and noticed this morning that a few spots need a little more. I’m using a sand grout and like I said it was placed just last night, do I still need to scrape out the newly placed grout at these locations to add more? Also I have an accent stripe of glass tile going around the whole room. It has very fine grout lines (not sure the size) do you have any recommendations for placing grout into small spaces? I attempted to do some by using my fingers but it was very slow so and I didnt want my grout to dry up so I moved to a different location. Finally, retailer told me that I need to seal glass tile once finished grouting, just wondering why?
Hey Kyle,
Yes, you need to remove that area of grout before installing new. The grout won’t stick to the grout – it sticks to the sides of the tile. You need to scrape it down to at least 2/3 the depth of the tile for the grout to get a good grab. You can also use the sanded grout for the glass (carefully so you don’t scratch the glass). Or you can get the same color grout in non-sanded for the glass – that may be a better, safer option for your glass. Use your regular grout float that you used for the rest of the tile.
The reason your retailer told you to seal the glass is simple: Your retailer doesn’t know any better.
No need to seal the glass (although you may want to seal the grout installed in the glass).
My husband and I did our first DIY tile project. I layed the tile, my husband grouted. The problem is, he didn’t put enough grout in the gaps and now there’s “low” spots. We haven’t sealed it yet, can we reapply more grout or should we score the dried grout and then reapply?
Hi Christina,
Grout in the grout lines will actually stick to the sides of the tile – not the substrate or the grout below it. This is what gives the grout stability. If you need to apply more grout you should remove enough of the existing grout so that at least 2/3 of the depth of the tile is exposed – this 2/3 is what the grout will stick to. If you attempt to simply reapply the new over the old it will eventually separate and crack out of there.
my husband and have recently tiled our kitchen and laundry room.it is a 35 year old house that had kitchen carpet in both areas.we removed the carpet and old linolmn was underneath.we installed backerboard thinset extra like you suggested on this site,which i read just now to make sure.now we have something like a fault line running through our grout.we did remove the grout down to the thinset and cleaned out as much as we could.then regrouted of course it cracked again within 2 weeks of the repair.i do suspect a tile is moving but is there any sure way to know if it is just that tile or more and if so what is the best way to fix it.also i am not sure why it would move with backerboard under it could it be the floor its self
If there is a small amount of deflection (less than 1/16″) in a small isolated area of the subfloor, would the use of an epoxy grout lessen the chance of the grout re-cracking?
This regular format tile has grout spacing of 3/16 to 1/4 “.
The original grout was cracking.
The original grout was ground out and replaced.
The replacement grout is debonding from the tile edges and coming loose in large chunks in some areas.
The grout itself is only cracked across one intersection in the area with deflection.
Of course the installer does not want to remove the tile to fix the subfloor deflection due to it being slight and confined to one area.
Thanks in advance for your time and comments.
Wes
Hey Wes,
What you’ve described is definitely due to movement in your tile. Epoxy grout will not solve that problem. The deflection needs to be fixed and the tile needs full support without movement for the grout to last. Epoxy grout will be very solid along the plane of the tile floor (you wouldn’t be able to pull them apart) but you will still have only 3/8″ or so – however thick the tile is – worth of support and all of that would be along the edge of the tile. It would lend no support to the underside of the tile. Eventually the stress of the tile moving up and down will crack that grout away from the tile or worse, actually crack the tile.
It doesn’t really matter what the installer ‘wants’, if you paid for a correct tile installation you apparently have not yet received that. Tell him to fix it correctly or you will have someone else do it and send him the bill. Sorry but it’s contractors like that which give legitimate people who take care of their customers correctly a bad name. I have to first convince someone that I’m an honest contractor before I even start talking about tile – because of crap like this. *Sorry for the rant*
It needs to be done correctly. If he continues to put ‘band-aids’ on it he will need to continue that forever.
Hi, Just an update on my failing shower. I had it redone with an experienced professional. Apparently any jackass can lay a floor, but only a tileman knows how to do a shower right.
Many mistakes were made in the first install too numerous to mention, but mainly: no floor pan, threshold not covered in rubber mat, no drip edges, incorrect floor pitch, faulty electrical and plumbing.
My best advice: Get an experienced tile guy for a shower, or anything to do with water.
Thanks for the advice, and I’m very glad that I had it redone right away to minimize damage.
Hallelujah!
I am so glad you decided to have someone QUALIFIED take a look at it and fix it.
And as a bonus you have the quote of the week!
“Apparently any jackass can lay a floor, but only a tileman knows how to do a shower right.”
Absolutely correct! Glad to hear it worked out even if it was the hard way.
Dear Roger,
) but I noticed one small void (less than two centimeters long and a millimeter wide at the most – sorry don’t know the ‘inches’ measurements 
) where I didn’t fill it with enough grout. Before I put on the tile grout sealer should I scrape all the grout out and regrout or could I simply scratch it open a little wider, just enough to give the new grout some purchase and regrout? I also got some grout on top of silicone (I siliconed the changes in plain first then grouted), will it just crack and fall off over time or should I scrape it off now?
I did a little first time DIY tumbled marble tiling and am really pleased with my results (rub fingers on chest
Thank you in advance for all your assistance.
Tami
Hey Tami,
You can just scrape out a little and fill it back up if you’d like. It shouldn’t be a problem at all with a spot that small. I’m actually metric literate so you’re okay.
Oops, missed part of the question. You may as well get the grout off of the silicone before you seal it – it’s gonna crack off eventually anyway. You may as well have it look the way you want rather than like it cracked off, eh?
Already stopped using shower. He didn’t realize that he had to caulk the intersections where the planes meet. He is going to remove most the grout there and silicone these joints. Should grout ever be placed OVER silicone? My other old shower doesn’t have silicone in corners, just grout, and doesn’t leak. This must be a newer code than my 50 yr old house.
He is also checking the plumbing, removing and replacing some adjacent floor tiles, and regrouting where needed.
What wall waterproofing are you reffering to? He had some black, tarp like paper in addition to the backerboard.
Thanks for all your help Grace
Hi Grace,
I apologize, I apparently am not making it very clear. The silicone in the corners IS NOT GOING TO STOP YOUR SHOWER FROM LEAKING. Your shower is leaking because the waterproofing membrane is compromised in some fashion. Grout should never be placed over silicone – it will not adhere and will crack and crumble to pieces. The black, tarp like paper to which you refer was (more than likely) used as a moisture barrier behind your backerboard. That is acceptable installation procedure for shower walls.
My concern here is that you have mentioned things such as ‘checking the plumbing and removing adjacent floor tiles’ ‘regrouting where needed’, ‘grout keeps cracking out’, ‘grout remains wet 2 days after shower’ and, of course, the biggest ‘water leaking into downstairs (from this shower)’. You have yet to acknowledge that the source of your leak is due to (short of a plumbing leak) a compromised liner. It sounds to me like you and your contractor seem to think that if he gets enough grout and silicone in all the right places that this will solve the problem. IT WILL NOT SOLVE THE PROBLEM.
The fact that your other shower doesn’t have silicone in the corners, just grout, and doesn’t leak has absolutely nothing to do with why it does not leak. It does not leak because it does not have a compromised liner in the base beneath the tile. When properly built you can take a shower in it without grout, silicone, caulk, anything, and it will be waterproof. I build showers with grout in the changes of plane – they do not leak. What substance is in the corners has nothing to do with how waterproof your shower is.
I’m not doing this to admonish your contractor, shit happens. It may not be his fault. I don’t know. I don’t care. The fact remains that, unless your plumbing has a leak, your shower is leaking because your waterproofing membrane in your shower floor is compromised. Everything you’ve described to me points right to it (cracking grout, wet grout, LEAK). Tearing out adjacent floor tiles, checking the plumbing, replacing grout at the plane changes with silicone, all these are fine. But short of the aforementioned plumbing leak, they do not change the fact, nor will they, that your shower floor is leaking.
I apologize for being an ass but there does not seem to be concern to an extent that warrants properly solving the problem. I’m saying there needs to be. If there is not this problem will compound into something much larger. The solutions that are being suggested are akin to cutting your arm off with a chainsaw and placing a band-aid over the wound. It’s not going to hold – knowwhatimean? The solutions being suggested are not going to solve the problem – period. You have water leaking downstairs, would you place a garden hose in your window and turn it on very low for 10 minutes twice a day?
I really don’t know how else I can say it. Your shower waterproofing membrane is somehow compromised – leaking. Short of diagnosing exactly how and fixing that problem everything you do is for naught. The rubber waterproofing membrane below your mud deck in your shower floor needs to be repaired or replaced. I don’t know how else I can explain that. Sorry if I sound like an ass. If it saves thousands of dollars worth of damage to your house – I’ll be an ass.
My problem is similar to Vickis. New shower & floor. 2 months in, grout keeps cracking in corners and now leaking water to downstairs. Contractor used backer board, mud mix on floor and some kind of rubber floor mat under tile. Sanded grout, and it is greater than 1/8″ wide. He “repaired” it once, by grouting over the cracks, but that didn’t last. What do I need to know here? This is a 50 year old house, first time bath re do. Also, maybe this is important, the grout that gets wet during a shower, takes 2 days to return to a dry appearance. Its really noticeable because it is beige and then turns and stays dark beige when wet. Is this bad grout? It was sealed twice before use.
Hi Grace,
Stop using that shower! Seriously.
I’ll start with the easy answer – no, it is not bad grout. Grout and tile are not waterproof. They never were and were never meant to be. Your shower should be absolutely waterproof before a box of tile is opened. Your shower, obviously, is not.
The fact that your installer attempted to repair cracking grout by grouting over cracks speaks volumes about his (lack of) knowledge on the subject. Applying sealer to tile and grout do not make it waterproof either – see above.
It sounds as if there is actually a waterproof membrane (the ‘rubber floor mat’) beneath your floor tile but it obviously is either cut and re-glued in the corners or simply installed incorrectly.
The fact that your grout remains wet 2 days after a shower and that he used backerboard beneath the liner tells me that there is more than likely no pre-slope beneath that liner. Water sitting at or below the top of the drain will do just that – sit there. As it slowly evaporates (not all of it ever will) it will force your grout lines to remain wet as this is where it evaporates through.
Is your grout only cracking in the plane changes? That is the floor-wall connection, where the walls turn, and any other change of direction of your plane of tile. By code any changes of plane need to be caulked – not grouted. If your grout is cracking on or around your curb that is a moot point.
Now I get to be the ass again. I hate that…
You have stated that you have water leaking to the downstairs. Your shower is built improperly. The membrane has failed in some respect allowing water to penetrate below the liner through the floor or into the wall behind it. If you continue to use the shower the problems will get worse, compound, and my dog will burst into flames. Please don’t do that to my dog. The wall framing around your shower (I’m assuming they are wooden 2 x 4’s and not metal studs) will actually ‘wick’ water just like a candle. It will swell, deteriorate, and cause unseemly amounts of damage to not only the tile and shower, but to everything else around and below it.
Think Grand Canyon – water carved it. I understand that is an exaggeration of possible damage but I do not want you to underestimate the amount of damage that can be done by an improperly built shower.
You need to have a qualified professional look at and assess the shower and what will be required to properly fix it. At the least I would guess the floor and at least two feet up the wall will need to be torn out and properly replaced. You haven’t stated how, or if, he waterproofed the walls but that needs to be taken into consideration as well.
Sorry to be the bearer of bad news (again). I’m getting real good at telling people what they need to hear rather than what they want to hear. Feel free to leave any additional information or questions here or, if you’d rather not discuss it in front of the entire world, you can email me at FloorElf@FloorElf.com to discuss what you will need to do to get this resolved. You can also read through my site to discover what should have been done in the process of building your shower.
And, as a bonus, if you send me your ‘contractors’ address I’ll send Guedo after his ass to have a little talk with him.
I just had my master bathroom completely redone, and today I was flipping through channels and they were talking about a vapor barrier, I know the contractor put tile on top of green board for walk in shower w/ backer board for floor as I checked progress everyday for the 5 months it took him. What do I do now? The bath is finished about 3 weeks old, Can I seal every month to avoid water problems or it is this a lot bigger problem, spent about 18,000+ on this also just noticed today that the raised edge to the walk in shower the grout is cracking I believe has non sanded grout what to do now?? My husband was so upset this took so long, and now will be really upset if we have to have redone.
Hi Vicki,
Sorry to hear about the problems. I’ll need to clarify a few things first before I can (hopefully) effectively help you out.
1. What part of the country are you located? I ask because in most (and it should be all) areas by city or county code, as well as anywhere by TCA standards, green board is not an approved substrate for tile. I assume that the ‘green board’ that you are talking about is in fact the (almost) regular drywall with green paper backing? That is green board but there are also two products that people call green board that are, in fact, not green board.
2. What did he use to adhere the tile to the wall? Was it a powder mixed with water (thinset – correct) or a pre-mixed product in a sealed bucket (mastic – absolutely incorrect)?
3. I assume (and hope to high hell) that you mean he used backer board on the regular bathroom floor AND NOT for the floor of the shower which requires a dry-pack mud mix. Is that correct?
4. How big are your grout lines? If they are 1/8″ or smaller it may be unsanded grout in which case it may just be shrinking. If they are larger than 1/8″ he used (incorrectly) unsanded grout in which case it is probably still just shrinking but should be replaced with the correct type of sanded grout.
Sealing your tile (even every month) will NOT make your shower waterproof. A shower should be waterproof before a piece of tile is touched. If it is not it is incorrectly built. Sealer is made only to prevent tile, stone and grout from staining. Not only that – if you paid $18000 to have your bathroom remodeled you should never need to ‘waterproof’ your tile – ever. Let alone every month.
If you could answer the above questions for me I can help you determine what your next logical step should be and whether or not I need to send Guedo
after your contractor.
Roger, is it possible/practical to remove a grout that is considered too light for the slate and replace it with something of a similar colour to the stone? I grouted the stone a few days ago, but I’m not happy with the colour.
When I bought the slate for my bathroom, I asked for grout samples, but they couldn’t provide them, so I asked their technical guy which one they would recommend if I wanted one to at least roughly match the slate in colour to give a homogenous look. They advised PCI groutfast 8 grey, so that’s what I bought. When mixing the grout I did notice that the grey was quite light, but I just assumed it would darken when dry because I trusted that they would have advised me correctly. However, it only got lighter, and it’s not from surface laitance because if scratched it’s a similar colour deeper down. The grout is so light compared to the slate that you hardly even see the stone, you notice the light grout lines, which is the opposite look from the one I was going for, unfortunately.
I’m concerned that if I dug out the grout and regrouted in a new colour, light bits would still show along the edges of the tiles where old grout still remained. Your advice would be appreciated
Hi Al, sorry to hear about your problem.
There are a couple of solutions to your problem, one being to remove and regrout. Before doing that, though, you may be able to darken the grout by using an ‘enhancing sealer’ made for stone.
This particular type of sealer is made to bring out the different shades and natural color of the stone and will usually do this by simply darkening it. If you wipe your slate with a sponge the slate will darken and enhance the natural coloring – enhancing sealer does the same thing but locks in the color change if that makes sense.
In doing this it will usually darken most cementious grouts at the same time. If you don’t want that look for your stone you can apply the sealer to only the grout and see if it will darken it. It may or may not, that depends greatly on the chemical makeup of the grout as well as the sealer.
If that does not work your next best option would be to regrout it. After you remove your grout you can get a ‘rubbing stone’ made for tile. It is made to ease the edges of cut stones. It basically ‘sands’ down the edge so it isn’t sharp. It will, however, remove grout as well. You can place the corner of the stone (get a square or rectangular stone rather than the round) into your grout line after you remove what you can and lightly rub it back and forth to remove any grout that may remain in the upper portion of the grout line.
That won’t remove any grout further down into the grout line but it should remove enough so that when you regrout it with the darker grout none of the lighter stuff will show.
Hope that helps. Let me know how it turns out so I can perhaps help someone else in the future with the same problem. If that doesn’t work let me know that, too. Knowing what doesn’t work is just as helpful as knowing what does.
Thanks for the advice! The bathroom is finished and looks sensational.
The sealant made the grout darker when wet but it was the same colour when dry. No-one seemed to sell rubbing stones. I read someone on a forum say he now uses diamond sandpaper instead. I didn’t get any of that either though, instead I just used a grout rake to make a deep v shaped groove in the grout, then I’d angle it by resting on one edge to grind the grout off the other edge. The tiles ended up looking scratched, but when wiped with a damp cloth I could see that the grout had been sufficiently removed.
I did not reseal the scratched tiles yet, because I wanted the new grout to have every opportunity to stick in what little cracks the old grout was still hiding in along the edges. When regrouting, I tried to keep it as flush as possible with the tiles. They, when it was finished, I resealed and the scratches in the slate ‘disappeared’ once darkened the same colour as the rest of the slate. Not one piece of white showing, success! Thanks
P.s. why not put a little bar of google adverts at the top or bottom of your site? That should give you some extra revenue to help reward your efforts, without ruining the look of your wonderful site.
Hey Al, Glad to hear it worked out! Sometimes the sealer will work and sometimes it doesn’t, like I said it depends on the chemical makeup of the grout and the sealer. Good to hear you got the finish you were looking for.
I’ve thought about google adwords but the problem is I have absolutely no control over what products are advertised on my site. I don’t want ads for crap products and have people somehow think I’m endorsing them. And there are a lot of crap products out.
I am going to open up a little online store here when I get everything together. People will be able to order the stuff from me that I recommend here – you know, stuff like a rubbing stone. Seems that for some reason it is not as available as I thought – I may as well make it so.
What I would like to do is to obliterate the grout lines between ceramic tiles enabling me to combine four tiles and paint over them creating one large square tile where previously there were four. I want a more contemporary look to the bathroom wall. I would even like to rough up the tile surface before painting for a two-toned effect. Is all this possible?
Hello Virginia,
I’m not sure what size tiles you currently have or whether they are already installed (I’m guessing yes). To “obliterate” the grout lines you would need to essentially float the surface of the tiles to be consistent throughout. It is not simply a matter of filling the grout lines with something.
If you notice the edges of your ceramic tile they actually taper down as they approach the edge. When installed this leaves a smooth taper down to where the grout line is created. To do what you want you would have to fill this portion of the tile as well to get a surface that looks like one large piece. Not sure how practical that would be but yes, I guess it is possible. (on a wall) I wouldn’t be able to recommend what to use for it, though. You need a product that would actually permanently adhere to the tile face. The only thing I can think of would be an epoxy based product. Bondo maybe? I wouldn’t do it but it’s not my house, eh?
If the wall you are speaking of is in a shower – don’t do that. It will not last.
You will need to rough up the face of the tile to paint it anyway. Make sure you use a paint that will properly adhere to your tile as well as withstand the environment.