Quick Answer: How to Seal Grout – First and most important, clean the grout completely, using a DIY hydrogen peroxide and baking soda paste, Zep Grout Cleaner and Brightener for tougher jobs, or a steam cleaner (use only the steam cleaner on natural stone). Let the grout dry fully, ideally overnight with a fan. Then apply a water-based grout sealer like Miracle Sealants with a brush-tip applicator, laying down a good bead so the grout can absorb it, and wipe any sealer off the tile. Stay off the surface for 2 to 4 hours, and reseal high-traffic areas yearly and everywhere else every 2 to 3 years.
One thing that’s often forgotten when you have tile and grout in your home is sealing the grout. If you skip it, you make the grout so much harder to keep clean. So let me show you the best way to seal your grout so it’s easier to clean and lasts longer.
This post is sponsored by Lowe’s. Always follow the usage directions on any product label.
Tools You Will Need to Seal Your Grout
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Before you seal anything, you have to get the grout completely clean, and if you ask me, this is the most important step of the whole job. Don’t skip it, because any dirt left behind gets locked in place under the sealer, and it just won’t look as good.
My first go-to is a simple DIY mix of equal parts hydrogen peroxide and baking soda, stirred into a paste about the consistency of runny toothpaste. Scrub it into the grout lines with a toothbrush or grout brush. The baking soda cuts through buildup with its gentle abrasive quality, while the hydrogen peroxide helps remove discoloration and kills bacteria. They work amazing together, they’re cheap, and you may already have both at home. Just remember that baking soda is very fine and can be tricky to rinse off, so go over everything a few times to get a truly clean slate.
If your grout is really dirty and the DIY mix doesn’t cut it, step up to Zep Grout Cleaner and Brightener. This stuff works incredibly well, but it’s very powerful, so wear your PPE, get good ventilation, and wear old clothes since it will pull the color right out of them. It’s a strong acid that cuts through buildup, and the brightener side helps even out grout that’s gotten discolored over time, which matters before you seal. As with the baking soda, rinse it thoroughly so none is left behind. Your third option is a steam cleaner, which uses highly pressurized hot water to blast out the grime with no cleaners at all, and many have a grout brush attachment to scrub as you go.
⚠️One important note: if you have natural stone, don’t use the baking soda and hydrogen peroxide mix or the Zep cleaner, because both are too powerful and can cause damage. Stick with the steam cleaner instead.
I know you came here to learn about sealing, but I can’t stress enough how much the cleaning and drying matters, because getting the grout clean and dry is what makes the sealer go on properly and look great. So once it’s clean, the next step is to get it completely dry.
I like to do this job over two days. It takes a little planning, but on the first day I clean the grout, put a fan on it, and let it dry overnight. That way the next day it’s completely dry and ready to seal, which ensures you’re not locking any moisture inside where it could cause damage.
The sealer I recommend is the basic water-based grout sealer from Miracle Sealants. I’ve used it all around my house, in friends’ homes, and in my business, and it just works great. Being water-based makes it easy to apply, it dries completely clear so you won’t see any spots you missed on the tile, and it has a nice low odor.
For application, I like an applicator bottle with a brush tip, since it’s all in one. Pick a point in the room and systematically work your way across the grout lines, leaving a good bead of sealer behind. Grout is essentially a sponge, so it soaks up the sealer and lets it penetrate, which means you need to leave enough behind for it to actually do its job. Keep a few microfiber towels nearby to wipe up any sealer that gets on the tile. It does dry clear, but I still like to wipe up as much as possible.
On vertical surfaces, the applicator can be tricky since you’re fighting gravity, so you can use a paintbrush to apply the sealer instead, or hold a microfiber towel right against the wall below where you’re working to catch any drips. It takes a bit of work, but it’s so valuable for keeping your grout clean and easy to maintain.
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Does One Coat Do It?
In most cases, one coat of sealer is all you need. But if you have a really dirty area or a spot like your shower with hard water buildup that could use extra protection, you can add a second coat. Just wait 30 minutes between coats.
Sealing doesn’t mean your grout is maintenance-free forever, though. If you ever spill something like red tomato sauce, still clean it up as quickly as you can, because the sealer buys you time but won’t protect the grout indefinitely if a spill sits there. The rule of thumb is simple: if you see it, clean it, and everything lasts longer.
After You Seal
Once you’re done, stay off that floor or surface for at least 2 to 4 hours. If you walk across it too soon, any dirt or hair you track can stick in the sealer and make a mess, so it’s best to keep people and pets out of the space while it sets.
For how often to reseal, I recommend sealing the grout in high-traffic areas like your bathroom and shower about once a year, and everywhere else every 2 to 3 years. If you’re not sure whether your grout has ever been sealed, here’s a quick test: dry the grout well with a towel, put a few drops of water on it, and watch. If the water beads up and sits on the surface, it’s sealed and good to go. If it soaks in, it’s time to reseal. And there you have it, the best way to protect your grout and keep it clean longer.
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