Seal Grout, step by step

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 pleasant protective coating on your grout. You do not absolutely have to, but it truly 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 pleasant 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 pointer 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- simply to be sure we did not miss a thing and that we have a pleasant 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 certainly paid off. I can proudly admit that I have had to scrub the shower grout exactly zero times since we initially sealed everything over five months ago (and I have not had to touch the floor grout either). Thanks to that pleasant impenetrable seal it looks like we in fact accomplished the lower maintenance bathroom that we dreamed of- and we did not 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 strong idea around six months after the initial sealing job- we figured we’d take you folks along for the ride in the form of a plain step by step walkthrough 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 will simply 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 in fact 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 took out so you can seal without worrying about getting it on the shower curtain, the floor mat, or the blender. We even took out our shower caddy to be sure there was not a centimeter of grout that was left inaccessible. So after we tossed a pleasant 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 are about to seal is clean and dust free. Since our grout was most certainly not stained, cracked, discolored, or mildewed we simply ran a microfiber cloth over the surface of the shower walls to grab any spare dust particles that we did not 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 is sealed- aka: do not scrub your tile and then try to seal it while it is still soaking wet).

Once you have your grout pleasant 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 simply read the bottle to see what materials it is meant for (some will specifically say “for use on marble or granite tile” or “specially formulated for dark tile” so it is pleasant to find one that works best with your surface- and you can consistently 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 ideal 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 fairly pricey at around $50 (although the special marble sealer at Home Depot was around $40 so it is not typically low-cost 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 simply for marble tiles that keeps them sparkling between annual sealing adventures. Plus we had more than sufficient for the initial sealing job back in January and still have tons left for touch-ups to keep things pleasant and protected throughout the years.

Next it is time to crack any windows that you can for a bit of pleasant ventilation- and turn on any and all fans (like the vented bathroom fan, or your ceiling fan or range hood if you are working in the kitchen). The reason that we mention doing this now is because once you’ve sealed something you are not supposed to walk on it or use it again for a few hours, so if you are sealing your way out of the bathroom or the kitchen, the last thing you want to do after you are 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 simply 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 quite thin grout lines so we like that it feels a bit more thorough than simply tracing each grout line once with an applicator brush- plus it has the brought in benefit of sealing our tiles while we are 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 are sealing whole sections of the bathroom, like the whole tub and shower surround and the whole floor. This is pleasant because natural stone like marble and granite can be quite porous and therefore a lot more prone to staining or damage if they are left unprotected.

Next it is simply 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 do not lose track of what I have sealed and what I have not 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 is not 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 has not because the sealed sections of tile should look slightly wet and the grout typically looks a bit darker where it has been saturated.

Another reason it is smart to work in smaller sections is because five to ten minutes after you’ve begun to apply your sealant, you will 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 took out 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 at last got to my third wall which I also sealed and then wiped down within about seven more minutes.

You truly 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 simply 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 would not cut into our showering time). By contrast our floor sealant only needed 24 hours to fully dry (but could be walked on in simply 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 is a small price to pay for months or a full year free of grout scrubbing and mildew battles.

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

Update: We at last created this Shop Our House page to assist you hunt down any furniture/accessories that you see in our house, along with all of our paint colors.