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.

{ 628 comments… add one }

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  • Laurie

    My kitchen counters were made with cracked tile. The grout was not put in deep enough on one counter. Now my dish rags catch on every point of the tile pieces. What is the solution?

    • Roger

      Hi Laurie,

      The countertop needs to be replaced – with non-cracked tile. And it was likely movement that cracked the grout out rather than it not being installed correctly (just an educated guess). It was likely not installed with cracked tile, either, the movement over time likely cracked it after it was installed.

  • Marie

    Question… what if the epoxy grout has only been in place for 24 hours but has sunk in, can i re-apply?

    • Roger

      Hi Marie,


  • Robert

    What if I have a 1 inch deep crack along wall where the wall pulled away about a 1/4 inch and need to fill with grout? Just fill with a lot of grout or fill half way with caulking then grout ? Thanks.

    • Roger

      Hi Robert,

      Fill it with backer rod, then silicone.

  • Mary Schutte

    We had our old fiberglass shower pan and wall tile removed and a new shower floor and wall tile installed about a month ago. I have noticed that the corners of the floor tile, which has a dark grey grout, take about 48 hours to dry. Could our installer have missed putting grout on these areas since they had similar colors? I’ve put a level on the floor and it does not seem to be sloping toward the walls. I am concerned about the continuous moisture, do you have any other ideas of what this could be and/or a recommendations for us to fix this?

    • Roger

      Hi Mary,

      Water behind the wall tile will run down the wall and onto the floor, flow beneath the floor tile and into the drain. It’s normal. Once it hits the bottom of the wall it needs to make that 90 degree corner, that may take a bit. Gravity pulls it down, but it takes longer for it to run down the floor slope. Since you said it’s only doing it in the corners (I’m assuming the four wall corners and not the floor to wall corner) there may be a sealant of some sort along the bottom of the wall tile forcing water into the corners. Find out from your installer if there is.

      • Mary

        Here is a photo of the areas remaining wet.

        • Roger

          Hi Mary,

          For some reason the photo did not show up. You can email them to me at Roger@FloorElf.com if you want to.


    Hi Roger

    First of all, thank you for having such website. A newbie like me, could definitely benefit from such information and having access to resources as such. I had the issue of cracked grout in my bathrooms. I apologize for any repeated question (and Im pretty sure there is already) or problem.

    7 days ago, after some weeks of excruciating pain (yes I did dramatized it a little) of upgrade work, I thought it was completed. but when i was doing the final cleaning (because the contractor was sloppy, and did not clean up some edges or excess grout on the tiles) i found out there are some cracked grout. I did a bunch of research and narrow down to a few possibilities (or ALL)… 1) the mixing was incorrect, too much water. 2) the grouting skills (although to some this is a no brainer) is bad and being care less…. 3) it could be the recent mad weather (extreme cold -28c/ -18.4f and “warm” +8c/46.4f) that result in expand or contract of the wall. there are several walls that i checked that is cracked or you could simply spot those grouts that is badly done, but this particular wall that backfaced outside wall (still in a insulated, and recent upgrade, my contractor confirms it. could be wind direction it could be structural but was assured that it was insulated and no holes from external) and explains why this wall’s bathroom is always colder than the others. 4) the line/ gap is too tiny even for unsanded grout. if this could also be the possibility, then what grout shall I use and is there such thing that is too tiny gap or line? And this is for the wall tiles.

    Anyway, basically my contractor’s assistant just did a sloppy job and now, besides the aesthetic side of things, it is also the potential water leak that made me have even a stronger urge to regrout this again. but like many others, I do have limited resources (be it time or money, and in my case, including tools). I have gone through a bunch of tutorials, and got myself a few simple basic tools, and I think I am ready to do this again. But before doing this, I have some questions and I need to seek your advise on

    FYI- We have white beveled subway tiles with no spacing (I don’t know exactly what that means too, our contractor was explaining that in the tiling “world”, it is the smallest spacing which to some it is consider no spacing but will still have a little gap but it is just not numbered like the rest). Like I mentioned, the last day of completion for all bathrooms are around 7 days ago? And since then, we have showered in those areas but it’s minimum as there are only 2 person uses these bathrooms. and the irony is, we did this upgrade work, is because the of the grout was failing and moldy and of course, the look needs to change as this house is 8 years old and no upgrade was done since.

    1) for this instance, can we grout it over the old grout. Yes I understand in an ideal situation, it is preferred to remove the old and then patch in the new. But unfortunately we have limited resources. But that said if is absolute no choice then we would. Also if we cant grout it, can we just remove the surface portion of it maybe 1/2?

    2) if we decided to use sealant on the grout, can we use sealant that is meant for tiles because it will again be time consuming to seal the grout line by line.

    3) some corners of our wet areas, we reinforce the lines with some silicon. Below are that particular type we used. A) is there a problem to leave it on top of the grout, as in effecting the existing grout’s integrity and B) as we are redoing the grout, we have no choice but to remove the silicon correct? If we do, will we effect the bottom layer (existing grout), and if not, can we just resealed those ares with the same type of silicon or a regular transparent silicon?


    3) how can we validate the grouts integrity. Reason why I am specifically asking this is because one of our shower room has granite hexagon tile. As it is shower room, we would like to make sure the grout is at it’s full capability, but yet knowing the contractor, we might need to check again. However like I said, we have limited resources and also it is a hexagon Tiles, it won’t be the easiest I am sure… from the look of it, it doesn’t look as bad as the wall tiles because the floor has bigger gap and the contractor can easily cover that part. also for grout as such, once stained from shampoo or dirt it has a layer of white spot (as per the pic but since this pic was taken, I manage to clean it to the minimum) but what’s the best way to clean it out and will I have to make sure the stain or dirt is out from the grout before sealing it?

    4) For redoing the grout, we intend to redo those wet areas. and for the dry or dryer areas such as around vanity or behind toilet, we may just either grout it over existing or simply scrape the excess off to make it aesthetically visible…. is that something OK to do?

    Lastly I have attached some of the pictures for your references and yes it upsets me everytime I look at the tiles or the pictures :( and yes I do know having beveled tiles is harder to grout, and yes understand having black grout and white tiles, the look or the lines are somewhat less forgiving due to the contrast in colour.

    Roger, once again thank you for your help, it is very much appreciated. Any further advise you have and willing to provide, please feel free and we are open to know or learn. And I am sorry for all these questions :(


    • Roger

      Hi Danny,

      First off – I know this is likely too late. Sorry for the delay. It sounds to me as if the grout was simply not installed correctly. I do not see any photos, so I’m going off of what you described. With smaller grout lines, or tiles with ‘lugs’ (very, very small grout lines) an unsanded grout needs to be used, and it needs to be FORCED into those grout lines in order to fill it. If it is just skimmed over then it will be weak, what we call a grout bridge, just covering the very top of the open space. In that instance you need to at least scrape out a portion of the grout to ensure you aren’t just grouting over a small, unsupported area, which will eventually fail. You need to ensure the line is being filled.

      As far as the changes of plane (where you have caulk), that needs to be removed, and the grout needs to be removed, then caulk ONLY. Having grout beneath the caulk may cause problems. The grout will crack, the caulk will not. You’ll have pieces of cracked grout behind your caulk.

  • Jen

    Had my shower floor regrouted a week or so ago. The contractor had his floor man remove all the grout and replace it. Let it set then came back two days later and said the job was complete. Was left with a lot of grout haze on the tile and what felt like loose sand on top of the tiles and in the grout lines. I took a sponge to it and find solid grout underneath. Is it normal to leave some loose on the top? Should I clean all of the shower out and seal? Or was it left purposely on top and should I just let it wash out naturally as I shower?

    • Roger

      Hi Jen,

      It should have been completely cleaned off.

      And yes, I realize this reply is likely too late, but the info will be here for others in the future. Sorry for the delay.

  • Deborah Herrick

    A few years ago my hubby hired what turned out to be a couple shysters to remodel an old cistern into a decent bathroom – shower, stool, sink. I was having serious ankle issues from a fall and couldn’t get down there until they were almost done. Boy, did we get screwed. Real marble sink is resin. Real wood is plastic. We bought nice tile for floor and walls. They put it in but by the time I got down there, they were sweeping some black stuff into grout space instead of grout. I refused to finish paying until job was done right. They never came back and we’re left with crap. My hubby obviously isn’t handy, I’m handicapped enough that I can’t fix it and we don’t have the money to redo it. What could the black powder be? I go down there about once a month so I usually take a look. White cottony mould grows in with that black stuff, not only on the floor but also in places on the tiled walls. I have to use the shop vac to get it off. I tried to find these guys through the city inspector, but he didn’t have an address and I think they skipped town. I want to cry every time I go in that bathroom. It’s useable but not by me. Shower floor isn’t finished around the drain, along with trim around the door. I’m still disgusted, but worried about that mould. Suggestions?

    • Roger

      Hi Deborah,

      I have no idea what that black stuff may be. There is nothing I am aware of that you would ‘sweep’ into a grout line. It MAY be polymetric sand, used for spaces between pavers, but given what you’ve described they likely don’t even have any idea what that is. It would be porous enough to where it would grow mold easily. Your best bet is to contact a reputable tile contractor to at least come out and take a look at it, then go from there once you find out what the hell is going on.

      And yes, I realize this reply is likely too late, but the info will be here for others in the future. Sorry for the delay.

  • Amanda

    Hi Roger, i hired a coworker to do a sidejob, gut and remodel my bathroom. Hes done tons of them. He left for a Thanksgiving break after working his main job then coming here for days. Im looking at his work after grouting the walls and floor. Im not happy. The tub walls are uneven in a sense of they are not flat and even. Theres ledges on top of the main tiles in places, more so under the accent tile stripe. The accent stripe seems to be inset morethan the regular tile. Also theres little thin vertical hairline cracks in grout around wall tile. The floor, deeper grout lines and theres light gray marks on top of the darker gray grout. What do i do. Hes coming back to finish in a day or 2. Can he grout over top of exsisting grout? And he has spacers still in wall tile in some areas. No grout yet around tub, just spacers. Is there supposed to be grout or just silicone between the tile and tub if its an actylic tub. I know they move/give a little. Not sure what he plans to do there.

    • Scott

      My advice to you would be to let the man do his job. Sounds like you are getting a bit antsy. Wait until he finishes, and then if you are not happy with the finished product, then you have an issue to complain about. I am a professional in this field and know that in the middle of the job, it will not look pretty.

  • Gary

    I just did the first bit of Spectralock Pro grout on my deck, maybe 1/7th done. It went okay, but I didn’t really get the grout lines full (well, not after I scraped off the excess with my epoxy float), and then seem to have washed out quite a bit more during the first wash. Will another coat of Spectralock adhere? If so, how long do I have, as it will probably need to be ordered?

  • Suzette


    Really hope someone can help me. We just had 12×24 plank floor tile grouted today by our installer. Three hours later I see pinholes in the 1/8 inch grout lines. He used a grout and mixed it with Aqua Tight sealer additive. Why is this happening? It wasn’t a water and grout mix, so too much water wasn’t the issue. He’s only grouted one small bedroom and bath and hallway. I’m so upset and don’t know what to do and am paranoid to have him grout anymore of our existing tile that needs grouting.

    Can this be re grouted if it’s within three days without taking out all existing grout? Could the additive have caused this, I think it’s highly unlikely. Please help, in tears!

  • Elizabeth

    Hi Roger- We have a glass block wall which is the length of our tub and extends about 5 feet up. It is on the outer wall on the side of our mid-century ranch. I assume it is original to the house. The grout is crumbling, chipping and discolored, especially in lower areas which are exposed the most to the shower stream. It looks like the grout was originally light gray and I would prefer white. I have no idea if the glass block has ever been regrouted, but it’s hard to believe the grout has held up for more than 60 years. I was hoping this could be an easy DIY and I could clean out the grout down an inch or so and fill in with pre-mixed urethane grout for glass block. But after reading your advice in this thread, I have concluded I’m being naive about this project. What are your suggestions? Should I rely on professionals or is there anyway I can do this myself? Thanks

    • Roger

      Hi Elizabeth,

      You can get a grout saw and saw the grout out of the glass. Once you get down about 3/8″ or so it should begin to have open areas (the space between the blocks) unless they set and grouted them at once, in which case the grout/mortar will be all the way through. Regardless if you remove the grout down about 3/8″ you can grout over what is left without issue.

  • Michelle

    Hi,I had my floor tiled 3 weeks agony a filet, it looked great but the light grey grout is now already very discoloured in places, it is like it is too porous and despite regular cleaning anything that is spilt will not clean off, is this normal? I am waiting on the tiler returning, thank you.

    • Roger

      Hi Michelle,

      It is normal for regular cementitious grout which is not sealed. It is porous, that’s why you want to seal it if it’s in an area that will see a lot of dirt and grime.

      • Michelle

        Thanks for your reply, I’m not sure what was used and understand that over time it would stain but after 3 weeks it is so much different colours, there was 70 sq meteres done through kitchen and living area even when the plumber fitted new radiators the dust has left it paler despite sweeping and washing the same day, is there anything I can do, thank you.

        • Roger

          You can clean it with a grout-specific cleaner then seal it well so it won’t be so porous. That will make it easier to keep clean.

  • Diane

    Hello and thanks for taking my concern?my floor tile was done 3 weeks ago. I need more grout added to the grout lines. Also, when they washed the floor when they were finished, they left like towel marks on the tile itself. I used plain water for cleaning the floor. Still has pattern on the tile as to where they wiped the floor after words. They dragged a large wet towel across floor

    • Roger

      Hi Diane,

      I would contact your installer and let him know about your concerns. If the grout lines are not full enough that is something he will have to do. You can likely get the wipe marks off with a little dawn dishwashing soap and warm water, depending on the type of tile (provided it wasn’t epoxy grout).

  • Stephanie Fleming

    Grout is cracking around a window in shower. I want to replace grout with ceramic tile caulk. Do I need to remove all grout before applying caulk ? Or can I remove loose grout and then use caulk?
    Thank you so much! I obviously hired the wrong contractor for this job!

    • Roger

      Hi Staphanie,

      You’ll need to remove all the grout first. Whether it’s loose now or not, it eventually will be. If that’s behind silicone it will debond the silicone.

  • Timothy CK

    I recently installed a backsplash with 1/4″ thick stone tile with 3/8″ spaces between each tile. I used a premixed grout as I didn’t need that much. After 48 hours I applied a liquid sealer and noticed cracks throughout. I didn’t think if was that big of a deal , but now I am thinking it is. It will be about a week out before I can get to it again. Can/should I just apply more grout? Thanks

    • Roger

      Hi Timothy,

      With premixed grout it WILL shrink as it cures, and 3/8″ grout lines are huge. It’s likely just due to the shrinking during cure. Yes, you can just go over it again with more grout.

  • Kathy

    I installed a mosaic tile in a shower floor. I used the shower kit for the floor under the tiles and applied my tiles on top of membrane just as the instructions stated. After using the shower the grout was cracking and chipping out. Some of the mortar seeped up through the grout after it started to crack out. I tried fixing and replacing the grout. I waited 3 weeks before using the shower again. The grout cracked out again. I need help in fixing this issue. It would be too much work to remove all the mosaic tile and I would probably damage the membrane below. What can I do to fix this issue. It appears to only be doing this in the area the water hits from the shower head and where we stand in the shower. Help!!!

    • Roger

      Hi Kathy,

      What ‘shower kit’ did you use? It’s difficult to answer that accurately unless I know the specific shower pan you installed.

      Cracking grout is indicative of movement in the substrate beneath your tile – either the bond of the membrane to the pan or the bond of the pan to the substrate. Water is not causing the issue.

      • Kathy

        I used a kit that I purchased from Menards. I can’t remember the exact name but it had a pre formed hard stroaform base and a red waterproof membrane that was applied on the top.

        • Roger

          And how was the shower base installed? Did you have thinset beneath the shower pan as you installed it? And is the waterproofing membrane a liquid or was it a waterproof sheet?

          • Kathy

            Yes thin set under pan and on top of pan. Then sheet membrane installed over that. It was like a really thick paper of some kind.

            • Roger

              That is the redgard shower kit. If you have cracking grout in the shower base tile then you likely have a bonding problem somewhere. Biggest cause is the pan not being bonded properly to the substrate. The other two causes may be the membrane not being bonded to the foam on the pan or the tile not being bonded to the membrane.

              Causes for that may be thinset being mixed incorrectly, Spreading the thinset and letting it set too long or simply not embedding whatever you’re attempting to bond into the thinset correctly. Movement of some sort is causing your cracking grout.

  • Austen Rose Thompson

    I had a contractor install marble mosaic floor tile (small) and he unfortunately wiped out too much of the grout. He then walked off the job and it’s been sitting unused for a year. I cannot rip out the entire floor and the grout lines would take decades to scrape out since it’s mosaic tile. I want to add more grout but I hear that’s bad. I need all the help I can get. Is my only option living with it or ripping out the entire floor?

    • Roger

      Hi Art,

      You can not use regular cementitious grout on it. You’ll need to have it grouted with either epoxy or a urethane-based grout. Either one should work to fill what you have. Ideally you would get it in the same color it is currently grouted (same manufacturer).

      • Austen Rose Thompson

        Thank you so much! I’ll look into it.

  • Lori

    My contractor had the walls painted in our bathroom addition during the time we were waiting for the tile to cure before sealing. The painter got blue paint and dirty water on our brand new white unsealed grout. I had asked the tiler to use an additive for extra stain protection and it appears that he didn’t. He used un-sanded grout with water. Some of the grout will need dug out but some can stay as is. It was grouted 10 days ago. We had been waiting for the epoxy shower floor to cure before sealing the entire shower all at the same time. I want him to go over the entire shower with another coat of grout. Can I have him use the additive this time, or will it not adhere to the grout that was done using water?

    • Roger

      Hi Lori,

      Sorry for the delay – website issues. You do not really want him to mix up the new stuff any differently than the old, it may look different.

  • Tom

    I put grout on a place stone shower floor today. It’s sands grout with some pretty big grout gaps. I cleaned to much grout from them and I also see my thin set poking through in some places.
    Can I just clean those spots out and regrout the whole floor?

    • Roger

      Hi Tom,

      Normally yes.

  • Heggy Gonzalez

    Hi roger my tile guy just grouted today and there are a bunch of holes is the grout. Reading through your posts it sounds like I can just go over it again since it has only been a day?

    • Heggy Gonzalez

      Here Are some pictures plus I thought it would be a lot darker can I stain it or just go over with a darker grout?

      • Roger

        Going over it with a darker grout will not work, you’ll see both colors. You can stain it if you want, but you’ll need to wait at least 28 days for a full cure.

    • Roger

      Hi Heggy,

      Yes, you can. But I’d make him do it, you know, since you’re paying him to do it correctly and everything… :D

  • Kevin Stock

    Hi Roger. Four days ago, my contractor grouted my new floors, but washed away too much of the grout. Is it too late to just add another layer to make it more flush with the tile? Btw, the day after it was done, I asked the contractor if it can be done, and he said no, that the grout was already rock hard. Thank you.

    • Roger

      Hi Kevin,

      Anytime up to 28 days when the cement crystals are fully hydrated.

      • Kevin Stock

        Wow! Thanks Roger. I thought the window for adding more sanded grout was only 2-3 days. Shall I tell my contractor he has just under a month to add another coat of grout? That would be much preferable than trying to take it all out. The lines are 1/16″ so I was told it would be next to impossible to remove the grout without damaging the glazed porcelain tile. Thanks again!

        • Kevin Stock

          Oh ya, yes I said he used sanded grout on 1/16″ grooves. Even the bag says it’s for 1/8″ or wider. It feels not only too deep (washed out) but also very coarse. The grooves are a complete dust trap. I used black grout, but it looks like I used white because of the dust! Should he have used non-sanded grout or is he ok to choose whatever he’s comfortable with? On the day of grouting, I suggested non-sanded grout and he said no.

          • Roger

            I always use sanded grout on 1/8″ and 1/16″ grout lines. But I know how to do it correctly, he doesn’t seem to.

        • Kevin Stock

          Here are a couple of photos. I repeatedly asked for high grout lines in order to achieve a unified, almost poured concrete look. The tiles are beautiful and they were laid well, but the grouting was clearly an afterthought. The contractor is willing to do another coat, but he says it’ll probably chip off. He asked me to research what coating I’d like to put on top. I was thinking maybe epoxy grout, since it’s like plastic and tends not to chip. What would you do if you were me?

          • Kevin Stock

            This one shows the black grout looking white.

          • Roger

            He used WAY too much water when cleaning the grout.

        • Roger

          You should tell your contractor to get in there now and fix his screw up. :D

          • Kevin Stock

            Thanks so much Roger! The tiler recently discussed with the contractor the possibility putting on one more layer of grout, but this time using non-sanded. He said he can’t guarantee it will not chip off, though. What I would like them to do is fix the situation in a way that will not void my warranty. I don’t care how they do it as long as they’re willing to stand by their work. If a second layer of something chips off, I need them to come back in and try something else. Their position is that it’s not an option to remove the grout and start again because that process will chip the tiles. He said he’s not willing to take that chance. Do you think it’s possible to remove the grout so they can start over? Or do you think they should just add another layer of unsanded? How about a layer of epoxy grout? I heard it’s super strong and smooth. They just think I’m being fussy and unrealistic in my expectations. But I don’t think so. I’ve made it very crystal clear on multiple occasions prior to the grouting that I wanted a seamless, unified look to the floor with high grout lines. I don’t like it that even when I sweep the floors, my black grout lines look white. I don’t want to have to mop the floors or vacuum the grout lines in order to make the lines look black. Your help in this has been invaluable. Thanks again!

            • Roger

              The unsanded may last, depending on the cause of the problem. If it’s simply low grout lines it should be fine, if there’s movement in the substrate it won’t last. Unsanded is a better option than epoxy in this situation. The epoxy will bond tenaciously to the sides of the tile, not so much to the existing grout. Being that there is currently more grout area than tile area to bond to the epoxy will likely not work well.

              Grout can absolutely be removed without chipping the tiles if it’s done correctly by someone who knows how. If he said that – he apparently doesn’t have anyone who knows how. If they’re willing to stand behind the unsanded option I would let them give that a go.

              • Kevin Stock

                Thanks again, Roger. You’ve been invaluable in this process. I’ve attached a photo I sent to the contractor and sub-contractor that indicates the kind of seamless effect I was looking for. I was surprised to recently notice that it is, in fact, impossible to clean my grout lines enough to make them look black. They always look white. It seems that not only was too much grout washed off, but the dark colour was washed out as well. Thanks again!

      • Jeanne-Marie Lovell

        I just grouted using polymer-enhanced sanded grout, but the tiling job we laid is kind of uneven. It was really hard to get the grout as deep as I wanted it. But you say I can lay more on top within 28 days?! It’s been less than 24 hours. Should I go for adding more? My only previous experience is making small mosaics.

        • Roger

          Hi Jeanne,

          Sometimes it works, sometimes it doesn’t. It depends on a lot of factors. Give it a shot, worse case you’ll need to dig it out and do it again anyway.

  • Jamie

    I just did one layer of grey grout to my backsplash with the new trend of grey color….I hate it.

    Can I just go over the grey grout with white? Or do I have to grout saw it? Will this ruin my new subway tile??


    • Roger

      Hi Jamie,

      You can, but it won’t be white, the gray will show through in areas and it will likely flake off over time. You need to remove the gray. No, it won’t ruin your subway tile.

      Stop following trends. :D

  • Christina

    I need some help. My husband and I just paid a lot of money to have a flooring company lay wood plank tile through out our downstairs (1200 sq ft). Needless to say they did an awful job and I’ve basically fired them. The tile isn’t completely level at the grout lines, there are holes in the grout where there were probably bubbles while they were grouting, and the grout lines aren’t the same sizes – plus some of the grout is sitting on top of our tile. In some areas I can still see the side of the tile itself and to make it worse I ordered brown grout to match the tiles and they put down gray. Now its on us to fix this mess.

    Besides tearing it up and redoing the tile – do I need to drill out all the current grout lines before i regrout the tile? The floors have only been down for about 2 1/2 weeks so its still new. Any advice you have is greatly appreciated.

    Thank you


    • Roger

      Hi Christina,

      If it is over about three days old you should scrape out the existing grout before filling it with more grout. Grout bonds to the sides of the tile, not the substrate beneath it, which means it has trouble bonding to existing grout and remaining stable. You can try to grout over it, but I’m afraid it will begin to sheer off after a couple of weeks.

  • Andrea

    Hi Roger,

    Our 1953 casita was remodeled with 12 x 24″ tiles through the 700 sq ft. The LR is on cement, but the bedroom was on a subfloor (after we ripped off the carpet and then the old, laminate, original tiles). The tile was installed, looked great, but nobody stayed there as it took awhile to pick out new furniture.

    After a few months, someone stayed there for two weeks and two of the tiles had cracked grout around them. That is when I asked the contractor to come over and they said that there is movement. When you stand shoulder width apart and shift your weight you can feel the floor move. We have cracked grout on a few tiles. The tile guy said he’d re-grout and if it happened again, he’d come back. As you predicted it has broken down again and looks like crap…and the tile guy is ignoring my calls.

    It sounds like you’re saying that I have to rip it up and retile! That’s the only option? Ugh! This tile wasn’t cheap. Maybe I’ll have to carpet the whole bedroom to cover up the crappy tile job instead. Hugely disappointed! How about a grout that has rubber in it? A malleable grout? Something else besides “rip it up”?

    • Roger

      Hi Andrea,

      Sorry, no such animal. Unfortunately that is the only long-term solution.

  • Josh

    I grouted a river rock shower floor 2 1/2 weeks ago. I haven’t done anything with it since as I have been waiting for the shower door to arrive. I have noticed that there are a couple of areas where I wiped too much grout out, causing low spots. Is it too late to just add additional grout over the top? If not, how do you suggest doing it? Just the low spot or the low spot and surrounding area for it to blend better?

    • Roger

      Hi Josh,

      You should be able to go over it just fine. Do the low spot and a portion of the surrounding area to blend it.