How To Seal Grout

Experts recommend thoroughly sealing your grout after any new tile work is done, but even those who have sealed it (or have had it done professionally) back when their floor, shower surround, or backsplash is newly completed should break out the sealer regularly (anywhere from every six months to a year) to keep that nice protective coating on your grout. You don’t absolutely have to, but it really cuts down on maintenance and keeps it looking mint for years to come.

What does sealed grout have over non sealed grout? Well, by not allowing moisture or dirt to penetrate the grout, it relegates these things to the surface, thereby protecting the look of your lines. In other words: white grout stays nice and clean and white. And any other colored grout looks as good as new (all while warding off mildew and other gross stains). And one tip that we heard from several tiling experts was that not only should we thoroughly seal our bathroom’s floor and wall grout two months back when we completed our big bathroom overhaul (learn more about that project here) but that we should go back in and reseal everything about six months afterwards- just to be sure we didn’t miss a thing and that we have a nice thick seal on everything (which can literally be the difference when it comes to having to scrub dirty grout lines to rid them of mold and mildew).

So far our initial sealing efforts have definitely paid off. I can proudly admit that I’ve had to scrub the shower grout exactly zero times since we initially sealed everything over five months ago (and I haven’t had to touch the floor grout either). Thanks to that nice impenetrable seal it looks like we actually accomplished the lower maintenance bathroom that we dreamed of- and we didn’t even have to give up white subway tile or the coordinating white grout to do it. Whew.

And because we heard from more than a few pros that sealing grout is a great idea around six months after the initial sealing job- we figured we’d take you guys along for the ride in the form of a simple step by step tutorial so you can seal your grout right along with us if you so desire. Of course we should mention that if you start with dirty, cracked, discolored, or mildewed grout, sealing that will do nothing to keep it looking clean (since you’ll just be sealing those flaws in). So you might want to go to town scrubbing the heck out of your grout to get it back to its original glory before taking on this project. And those who are dealing with especially nasty grout can actually dig it out with a grout knife and regrout the whole tub or floor- which you can learn more about here in this post and by asking the experts at your local home improvement center.

But back to sealing the deal grout. The first step is to clear the room. That means everything on the floor or the shower walls (or your kitchen backsplash) must be removed so you can seal without worrying about getting it on the shower curtain, the floor mat, or the blender. We even removed our shower caddy to be sure there was not a centimeter of grout that was left inaccessible. So after we tossed a nice little pile of bathroom stuff in the nursery we were well on our way to step two.

The second step is to ensure that the grout (and surrounding tile) that you’re about to seal is clean and dust free. Since our grout was most definitely not stained, cracked, discolored, or mildewed we just ran a microfiber cloth over the surface of the shower walls to grab any spare dust particles that we didn’t want to seal into our sparkly white grout lines. And as for the floor, we did some sweeping to be sure that we picked up every last spec of dust and hair so that surface was also good to go. Again, if your grout is not in stellar condition, this would be the time to clean the heck out of it (note: be sure to read the back of your sealant instructions to see how long the grout must be dry before it’s sealed- aka: don’t scrub your tile and then try to seal it while it’s still soaking wet).

Once you have your grout nice and clean and dust free, the next step is to whip out your sealant of choice. There are tons of sealants that you can choose from at your local home improvement store, so just read the bottle to see what materials it’s meant for (some will specifically say “for use on marble or granite tile” or “specially formulated for dark tile” so it’s nice to find one that works best with your surface- and you can always ask the experts in the tile area if they have any recommendations if you find yourself standing there scratching your head over all the options). We opted to use this sealer from Home Depot for the white subway tiled walls of our shower/tub since the description sounded perfect for the job:

And when it came to our precious dark marble floor with mocha grout lines, we purchased this specialty sealer from The Tile Shop since it not only said that it works on all surfaces but was specifically formulated for marble (we felt it was safer than relying on something that lists a wide range of materials, only one of which is marble). It was pretty pricey at around $50 (although the special marble sealer at Home Depot was around $40 so it’s not usually cheap stuff anyway), but the box not only included the sealer- it also had a sponge, a grout brush applicator (for anyone with thicker grout lines), and a special cleaner formulated just for marble tiles that keeps them sparkling between annual sealing adventures. Plus we had more than enough for the initial sealing job back in January and still have tons left for touch-ups to keep things nice and protected throughout the years.

Next it’s time to crack any windows that you can for a bit of nice ventilation- and turn on any and all fans (like the vented bathroom fan, or your ceiling fan or range hood if you’re working in the kitchen). The reason that we mention doing this now is because once you’ve sealed something you’re not supposed to walk on it or use it again for a few hours, so if you’re sealing your way out of the bathroom or the kitchen, the last thing you want to do after you’re all done is walk back across your freshly treated floor to open a window or turn on the fan.

Then you should decide how you want to apply your sealant. Some people like to just seal their grout with a grout sealant applicator brush (which is sort of like a wire-y nail polish brush that can be traced along a grout line to distribute sealer along that groove. We prefer to rely on the sponge because we have very thin grout lines so we like that it feels a bit more thorough than just tracing each grout line once with an applicator brush- plus it has the added benefit of sealing our tiles while we’re at it (which can also be sealed to keep them more stain resistant and to protect them from moisture penetration as well). In other words by applying our sealant with a sponge we’re sealing entire sections of the bathroom, like the entire tub and shower surround and the entire floor. This is nice because natural stone like marble and granite can be very porous and therefore a lot more prone to staining or damage if they’re left unprotected.

Next it’s just time to sponge on that sealer. I prefer to pour small amounts of sealant straight from the bottle onto my sponge by tipping it to get a good splash or two on there. Then I work in small sections to be sure that I don’t lose track of what I’ve sealed and what I haven’t and I apply the sealant in a circular motion, sometimes working back and forth or up and down to get the edges of things. This isn’t exactly a gentle process, you have to apply a good amount of pressure to work the sealant into those cracks. As you go you can subtly see what has been sealed and what hasn’t because the sealed sections of tile should look slightly wet and the grout usually looks a bit darker where it has been saturated.

Another reason it’s smart to work in smaller sections is because five to ten minutes after you’ve begun to apply your sealant, you’ll have to start wiping it off. Of course we recommend following the specific directions on the sealer that you purchase, but both of ours had a time limit within that range that they recommended as the wait time before wiping. This meant that I could seal one out of the three shower walls (which took about seven minutes) and before I moved onto the second wall I used a dry rag to wipe down that first wall since any excess sealer should be removed within that 5-10 minute range. Then I moved on to the middle wall, which I sealed and then wiped down after around seven, and finally got to my third wall which I also sealed and then wiped down within about seven more minutes.

You really only need to do one or two passes with a clean dry rag (I like to do a light pass to get any obvious droplets off and then I do more of a “buffing pass” where I gently buff the surface of the tile so it sparkles, which more thoroughly removes any excess.

Then you just leave everything undisturbed for the amount of time that it says on the bottle. Our shower sealant said it needed 48 hours to fully cure before it could get wet (so we strategically applied it on a Friday night when we knew we’d be out of town for the weekend so it wouldn’t cut into our showering time). By contrast our floor sealant only needed 24 hours to fully dry (but could be walked on in just two hours) so be sure to read those labels to see what yours calls for. Either way it should only be a day or two at the most that your room is out of commission, and that’s a small price to pay for months or a full year free of grout scrubbing and mildew battles.

Then you’ll just want to repeat this whole sealing thing every six months to a year if you can, just to head off nasty discolored or mildewed grout before it gets a chance to rear its ugly head. It’s just a smidge of maintenance to keep your bathroom looking mint, so we definitely think it’s worth the effort. We’re thinking every year from here on out will work just fine for us. What about you guys? Are you overdue for a grout sealing adventure? Has anyone already sealed theirs and noticed the easier maintenance perk that we’ve mentioned? Dish the grout sealing dirt.


  1. says

    this post couldn’t have come at a better time! i am about to start kitchen renovation and i’m doing a white subway tile bakcsplash and i was getting very high strung about it getting dirty! kitchens get dirtier than bathrooms, you think it will keep my kitchen tiles nice and clean if i do this right from the beginning? thanks guys you are real lifesavers!

    • says

      Hey Maria,

      Yup, doing it right from the beginning and every 6-12 months thereafter should protect your tile and grout so it stays nice and clean!


  2. says

    A tip we learned from a friend in the biz is to put the sealant in a spray bottle and just mist it on then wipe off. He also gave us a spray-on car wax to use on our granite counters (we never put food on the counter) and you wouldn’t believe the difference in shine. I’ll have to check on the name of it when I get home.

    • says

      Amanda- Industry standards dictate that a line of tub and tile silicone caulk is best for the edge where tile meets the tub (far superior over grout for that crack) so that’s what we did when it came to our bathroom reno. We didn’t have any issues with ours! Hope it helps.

      Megean- We’ve heard that loose tiles can be chiseled out and reattached with thinset (and then regrouted). You can probably google around for a simple tutorial or even find a how-to video on YouTube. Hope it helps!


  3. says

    Thanks for the tips! I am getting ready to tackle some regrouting, and this is very useful informaiton.

    In your expansive DIY research and renovation endeavors have you come across loose tile issues? Some of my bathroom tiles are starting to come loose from the walls (the grout is pretty much intact, but if you put pressure on the wall you can feel some give), and I’m wondering why. It’s pretty sporadic, though there is one whole section in the shower that could give way at any moment.

  4. Kate says

    Perfect timing! I’m on vacation next week with no plans…looks like the kitchen floor is going to be sealed! When did my life take this turn?! Vacations used to be spent at the beach drinking rum runners…now I get excited about grout! I wouldn’t have it any other way though!

  5. says

    Wow! This is great! I didn’t realize that you need to seal the grout too. We’re getting ready to clean up some grout on a new rental house we’re purchasing. For some reason, I thought the sealer was already in the grout… maybe there are some grouts that have sealer in them??? I guess I need to read more about this. Thanks for bringing it to my attention. You probably just saved me a lot of time in a couple of years!

  6. Elizabeth says

    Thanks for this post. A quick question for you.

    We recently purchased a house where the bathroom had been retiled probably 3-4 years ago. They did not seal the grout and it has gone from being white to a not-so-lovely shade of gray.

    I would like to return it to its original white color and then seal it. However, I’ve not had good luck in getting it clean. I’ve even broken my no-harsh-chemicals rule and scrubbed it with a bleach-based cleaner, with little effect.

    Any advice on this? Or do you think it’s beyond hope? Is the next step to consider regrouting the whole thing?

    • Amanda says

      For anyone else in this situation (I currently am, but with atrocious mauve-y pink grout! and I’m renting so I refuse to regrout), The Lettered Cottage had a post about what they did to their grout that was extremely helpful to me (with links to the products they used):

      They used Antique White, so if your tiles are white you might want to go with one of the other whites they carry. Just search Grout Renew for all of the color options.

      There are even video tutorials on youtube that I checked out to make sure this would work for me.

      Hope this helps anyone else in a similar situation!

    • Chris says

      I know this is really dated, but, I thought I would share my current experience with both cleaning and sealing grout. Hopefully others find this just as useful.

      All of our grout (floors, back splashes and shower walls) is originally an ivory color. Our home is just over 6 years old. The grout was never sealed (yeah, I know). The wall grout is generally fine. However, as you can imagine, the floor grout, especially in high traffic areas has become atrocious regardless of how much floor cleaning one does! As embarrassing as it may be, my grout was a very dark gray along quite a number of grout lines.

      I finally had the time to deal with this problem. My goal is to restore the ivory grout lines to as close to the original as I can get. Over the years I have tried a multitude of products, home brewed, commercial and industrial strength, none of which worked. I was at my wits end and recently decided that I would simply have to re-grout entirely (I have A LOT of tile in my over, over 600 square feet of floor tile alone). A friend of mine offered a suggestion, and, that is what I am here to share now with everyone.

      The product suggestion from my friend was Soft Scrub with Bleach. Apply liberally to your grout lines and let it stand for 15 minutes. If you have very dirty grout (like myself) I grabbed a grout brush and lightly scrubbed along the grout lines. Wipe clean with a cloth or paper towels (in fact, might as well spread that excess on your ceramic tile). No need to get the product on the grout lines entirely dry. My grout was very close, if not a little brighter, than the original ivory grout! After a few hours any remaining Soft Scrub will form a powder residue. Do not bother with a wet sponge as it will not help. Instead, grab a clean microfiber towel and wipe along the grout lines while applying some slight pressure. This will remove any and all remaining Soft Scrub residue on your newly restored grout lines.

      Being that grout is highly porous you want to wait until 24 hours after the initial Soft Scrub application and its corresponding removal. Time to seal the grout! My product of choice is Miracle Sealer 511 Impregnator (I in no way am affiliated with the manufacturer, I just did my research) and is available in most home improvement stores. This is a professional and high quality sealer for a multitude of materials, reduces the static coefficient of the surface (reduces skidding), is a penetrating sealer and not a surface sealer (which is what you want), will not discolor the material after a full cure, has an antimicrobial agent already mixed in and is backed by the manufacturer for 20 years (although, in reality, you will get somewhere between 7 and 10 years without having to reseal). I opted to use a brush applicator attached to a 4oz bottle rather than a sponge, a specialized applicator or towel so that I could precisely trace along the grout lines without wasting any product on my ceramic tile (my ceramic tiles do not have any staining or discoloration issues after all this time and really do not need to be sealed). Apply it (no real need to wipe off excess with a towel unless you are using some other application method) and let it dry. Normal traffic can resume in 1 to 3 hours and a full cure takes 24 to 72 hours. Depending upon the porosity of the surface you just might have to apply a second coat (this stuff goes a long way).

      The way to test for whether you need an additional application of the sealer (actually, any sealer for that matter) is after the specified curing time to execute the water test: drop some water on the sealed surface and if it beads up you are good to go! Otherwise, you need an additional sealer application.

    • missy says

      I used baking soda and mr clean with febreeze till it made a paste then scrubed with a denture brush thier alot harder then a tooth brush then just mopped it with hot water youll want to change your water and go over it a second time or it will leave a powder when it dries but i did the bath floor in about20 min and its all clean now

  7. Shelly says

    Great tip!! Thanks guys…look like at the end of July our shower will be getting re-sealed.

    p.s. We have the same shower caddy.

  8. AJ says

    Thanks for the tips! You guys are great.

    I have a sort of related question. Our new home has marble tiles in the bathroom, both on the floor and as the shower surround. What products do you use to clean those lovely mocha marble tiles in your bathroom? I’ve heard that some cleaning products can eat away at marble.

    • says

      Hey AJ- That’s true, anything acidic or too heavy-duty can etch the marble permanently, so you definitely want to be careful with what you choose to clean with. We love mild natural soaps like Ms. Meyers All-Purpose Cleaner (which we water down before using) and vegetable based soaps like Dr. Bronner’s (also watered down). There are also cleaners specifically made for marble that you could pick up.

      Elizabeth – if you’ve already tried the harsh stuff then it may be beyond hope, unfortunately. Our only last ditch suggestion is to see if you can find a special grout bleaching pen at a home improvement or specialty flooring store. Good luck!


  9. says

    I didn’t know you were supposed to reseal that often–good to know! I love it when you guys post house upkeep tips like these. It’s the kind of stuff that’s so helpful to know if you don’t want to hire someone to do every single little task that you could really do yourself. Thanks!

  10. Lauren says

    I would love some tips on how to CLEAN grout. We have white tile floors with white grout in our kitchen (bad bad idea-but it was done by the previous owner and we will not live in this house long enough to make replacing the floor worthwhile) and in some places it looks terrible. The only two things I’ve tried are magic erasers (SUPER tedious) and bleach (not an option with an infant around now).

    I would love to get it super clean and resealed. Again, redoing isn’t an option unless you have some super DIY ideas!

    • Kate says

      So, I realize that I’m about 2 years late in leaving this comment, haha, but I’m reading over all of this as we prepare to clean and seal our grout! For your sake, I hope you were able to figure out a solution, Lauren. But if not, have you tried a steam cleaner? I’ve heard awesome things about using steam for grout in floors. I’m going investigate further to see if it will work for my tile surround in the shower. (Anyone have any experience with the steam cleaners?) I think companies like Stanley Steamer will do it if you don’t want to DIY it!

    • Karen says

      I have tile in my laundry room and three of my bathrooms. I scrubbed until I was exhausted to keep the white clean, finally I called the flooring company and was told that they could color the grout. I contacted them and purchased grout color – easy application and I changed my grout to grey! No more worries about keeping it spotless white!

  11. says

    so…. we just moved into a new house and thought that the grout was sealed by the contractor – but at our 30 day walk through we learned it was not :( can we seal it now? do we have to regrout because it has been exposed to water? we have white tile and grout and I want to keep it shiny!

    • says

      Nicole- Yes! Clean it well and seal it as soon as possible to protect it from here on out!

      Lauren- Good point! Everyone feel free to chime in with grout cleaning tips! Share and share alike!


  12. Tracy Adele Jones says

    It was recommended to me (by a contractor I met in the hardware store) that you should seal your old grout before adding a new layer of fresh grout (and sealing). That way the yucky stains don’t penetration through to the new grout. Makes sense. Has anyone else heard this?
    Also, I used the aerosol sealer and I can tell you you need LOTS of ventilation! I’m normally not very cautious and that stuff gave me huge headache even though I had the window open. Next time I’ll use a box fan to pull out vapors and take lots of breaks.
    By the way, the line of caulk around the tub allows the tub to move freely (microscopically anyway) from the wall of tile. Otherwise you’re likely to get a crack in this area.

    • Colette says

      I have never heard of putting new grout over old grout. To do the job correctly, remove the old grout first. That is a project I will be taking on soon. Great info on this site.

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