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Grout, which is a mixture of cement, sand, and water, often with color added, serves to fill the gaps between tiles. But whether those tiles are on your floor, kitchen counters, or bathtub surround, one thing is inevitable; eventually, splashes or water or other liquids cause discoloration, mold growth, and damage. There’s a solution, however: grout sealer. Applied annually–or even every six months if the tile often gets wet–you can lock moisture out of the grout, keeping it looking its best far longer.
Applying grout sealer is a simple–albeit tedious–procedure, well within the abilities of even a beginning DIYer, and typically accomplished in just a few hours when the right products are used. We’ve made it even easier by researching the many types of grout sealer available and then whittling them down to those that do the best job for various applications around the home.
Here, the best grout sealers on the market:
Best Overall: Aqua Mix Sealer's Choice Gold Quart
Grout is both decorative and protective, and acts as a filler to cover any space between tiles to form a solid surface. Since grout contains a portion of sand, it needs protection from a sealant to last. Sand is porous, having small holes where dirt and bacteria can remain. The best sealers block these holes as much as possible.
The Aqua Mix Sealer's Choice Gold Quart takes the top spot for its natural looks and extensive protection. This product is a water-based sealer that provides ample protection over the entire surface, including grout and tiles. It also dries with a no-sheen finish for a natural look. For ceramic tiles, this will provide additional protection, and can be used with stones such as granite, marble, masonry and limestone. Use this as a pre-grout sealer on your tiles for extra protection in areas such as bathrooms or kitchens.
Best Budget: Black Diamond Stoneworks Ultimate Grout Sealer
Not all budget grout sealers will do a good job of protecting the grout from dirt and germs. While an inexpensive option is a good choice for larger projects or for tighter budgets, you need to be sure the sealer gets the job done. The Black Diamond UGS PT Ultimate is the best choice for this since it’s meant to fight mold and mildew growth.
The sealer is designed to repel oil and water, which can lead to extensive damage in the grout over time. In places where moisture is common, such as the kitchen or bathroom, this type of protection will reduce the amount of maintenance your grout and tiles will need after extensive use. The sealer will also repel food, grease, mildew, as well as mold to prevent harmful bacteria from developing.
Best Impregnator: Miracle Sealants 511 Impregnator Penetrating Sealer, 32 oz.
The challenge with grout sealers is depth. Since sand is porous, deeper holes need to be addressed depending on the thickness of the grout. Most sealers use a water-based solution that stops near the surface to protect the outer layers. To reach further in, an impregnator like the Miracle Sealants 32-ounce bottle is necessary.
This sealer uses a solvent-based formula that penetrates deeper into the grout layer. The deeper penetration means extra, longer-lasting protection for the grout and surrounding tiles. The sealer dries into a slip-resistant finish, so it is safe to walk on treated tile floors without worry. The extra protection will also keep stains from forming, preserving the look of the tile surface.
Best Spray-on: Miracle Sealants 511 Spray-on Grout Sealer, 15 oz.
Applying grout sealant can be a tricky process depending on the method of application. Bottles require extra time and attention, along with a tool, sponge or rag, to create a solid layer. Spray-on sealers are a great alternative since it is easier to get a level and complete finish over the grout and other surfaces.
The Miracle Sealants 15-ounce spray bottle uses a consistent pressure spray for equal coverage on the surface. The formula can be applied to grout, concrete, brick and other natural stones (should you want to have a single protective layer over the surface as well). For floors, you can use the spray inside and out since it will resist the common moisture levels found in outdoor environments.
Best Tube: Custom Building Products TileLab
Tube grout sealers allow for precise control over the sealant as you work. Since their supply is often more limited than bottles and spray-on alternatives, tubes are best used for small projects or for touching up leftover spots. Over time, you can keep a tube like the Custom Building Products TileLab for spot repairs to keep the sealer intact with extended use.
The tube contains 6 ounces of sealant, which should last a long time for the occasional touch-up or repair. Once fully dried, the sealer will resist mildew and bacterial build-up, making cleanup in bathrooms and kitchens easier and safer. The sealant also provides stain protection on tiles.
Best for Large Jobs: Tuff Duck Natural Stone & Grout Sealer
Larger projects require more sealer to get a quality coat and deep penetration. Gallon sealer bottles are the most cost-effective for this size. With a gallon bottle, you will have enough to finish larger projects up to 800 square feet (and still have some often leftover). You can then store the additional sealer for later touch-ups.
Tuff Duck’s Natural Stone & Grout Sealer gallon bottle is a multipurpose sealant formula designed for both grout and tile surfaces alike. Being non-acidic, the formula is safe to use on natural stones and concrete to protect the appearance of the surface. For grout, the sealer will penetrate to the bottom so all of the natural pores are covered up for better moisture and bacteria protection.
Best Multipurpose: Black Diamond Stoneworks Granite Sealer
Sealant formulas vary depending on the brand and manufacturer. Some formulas are specifically for grout and nothing else. If you have a project where other hard surfaces need protection, a multipurpose sealant like the Black Diamond Granite Sealer may be a good alternative.
This sealer comes in a 16-fluid-ounce spray bottle designed for small projects or light touch-ups. The formula is non-toxic and non-corrosive, making it safe for granite, concrete, as well as other stones in addition to grout. As a water-based formula, it is also safe for food contact if you want to apply extra protection to things such as granite countertops in the kitchen. Application is easy: spray and wipe away any excess.
Aqua Mix Sealer's Choice Gold (available at Amazon) takes our top spot thanks to its no-sheen, natural appearance, suitability for use over many types of natural stone and tile as well as grout, and superior protection against moisture and staining. But if price is a major concern, turn instead to Black Diamond Grout Sealer (available at Amazon). This product is only for sealing grout—it won’t help protect your tile or stone surfaces—but it’s easy to use and does protect white or colored grout from moisture and oil.
What to Look for in a Grout Sealer
Grout sealer is available in spray-on formulas, ready-to-apply tubes, or larger quart and gallon size containers that require rag or sponge application. Take your pick of how you’d like to apply a sealant to your grout, keeping in mind the square footage you need to cover. While a tube of grout sealer is convenient, it probably isn’t a practical choice for larger jobs. Spray-on formulas help achieve a consistent, even layer of sealant over the surface, but gallon-size containers will offer the most bang for your buck.
Water vs. Solvent Based
Some grout sealers are water-based formulas, while others are solvent-based. Water-based grout sealers offer more surface-level protection and won’t penetrate as deeply into porous grout, but they also don’t produce as many odors or VOC’s as some solvent-based formulas. For deep protection of your grout, however, a solvent-based impregnator-sealer is the best bet since it’ll fill spaces and protect your grout from deep within.
While some grout sealers are intended for grout only, other formulas can be used on cement, granite, and other types of natural stone. Look for a non-corrosive formula to ensure that it won’t damage your treated surface. And if you plan to use it on a food prep or dining surface, like kitchen counters or a bar top, then look for a product that's non-toxic and safe for contact with food.