What’s the Difference? Sanded vs. Unsanded Grout

Which type of grout is best for marble floors, and which should you when tiling walls? Learn the ins and outs of sanded and unsanded grout before starting your next DIY project.

By Tony Carrick and Katelin Hill and Bob Vila | Updated Jun 30, 2022 2:00 PM

sanded vs unsanded grout

Photo: istockphoto.com

Any homeowner undertaking a DIY tiling project will work with grout, a putty-like mixture that fills the space between tiles and keeps them securely in place. But while grout is commonly used for home improvement, many do-it-yourselfers don’t realize that it comes in two varieties: sanded and unsanded.

Whether you’re installing a kitchen backsplash or laying an entryway floor, read on to compare these options head-to-head—sanded vs. unsanded grout—so that you can make the right decision regarding what grout to use when it comes time to select your supplies at the home improvement store.

Sanded grout is more resistant to cracking and shrinkage than unsanded grout.

As its moniker suggests, sanded grout is held together with fine particles of sand. The sand gets suspended in place as the grout cures, leading to increased stability, better resistance to cracking, and less grout shrinkage. Sanded grout, like Custom Building Products’ Simple Grout, is easy to find both online and at home improvement stores and online. Sanded grout comes in a wide variety of colors and is budget friendly because sand is an inexpensive filler.

Sanded grout is the preferred grout for tile floors.

sanded vs unsanded grout

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Sanded grout is more durable than unsanded grout, which makes it the best grout for floor tiles. The sand filler in the grout creates a tougher bond and shrinks less than unsanded grout when it dries. Because sanded grout is stronger than unsanded grout, it’s better suited for the wider joints typically found between floor tiles. Whereas unsanded grout is appropriate for joints only up to 1/8-inch thick, sanded grout is strong enough to fill joints up to 1/2-inch thick.

Sanded grout is a better choice for tile projects that have wide joints.

Since sanded grout bonds better and shrinks less than the unsanded variety, it’s the preferred mix for tiles with joints ⅛- to ½-inch thick. Trying to squish bulky, sanded grout into thinner joints often results in a messy, imprecise finish that’s prone to cracking.

While water can be added to sanded grout to achieve a thinner consistency for smaller joints, we advise against doing this. Thinning sanded grout can result in pinholing, which occurs when the excess water evaporates and compromises the structure of the grout. Also note that for joints that are ⅜ inch or wider, you will need a wide-joint mixture grout that is more heavily sanded.

Unsanded grout is smooth, flexible, and held together with polymer.

Even though sanded grout is stronger, unsanded grout is sometimes more appropriate for a job. Unsanded grout’s smooth texture makes it a better choice for tile projects with thin grout lines, or situations in which sanded grout may scratch the tile’s surface.

When deciding when to use unsanded grout, it’s important to keep in mind its price and limitations. As we’ve said already, unsanded grout is not as durable as its sanded counterpart. Unsanded grout products, such as Custom Building Products’ Non-Sanded Grout, also use pricey polymers as bonding agents and can thus run up a renovation budget quickly.

Unsanded grout is best for joints that are less than ⅛-inch wide.

sanded vs unsanded grout

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Unsanded grout is thinner than sanded grout because it doesn’t contain the silica that bulks up sanded grout, and is thus easier to work into narrow joints. This thinner consistency makes unsanded grout the best choice for any joints that are narrower than ⅛ inch. Sanded grout, in comparison, won’t compact down to properly fill these narrower grout lines, making it more likely to slump, crack, or leave gaps.

Unsanded grout is your best bet when you’re working with soft, polished tile like limestone and marble.

Always use unsanded grout when working with a soft, smooth, polished tile like limestone or marble, since abrasive sanded grout will likely scratch its surface. Unsanded grout does not have silica aggregate filler found in sanded grout, which means it won’t scratch the smooth surface of such materials as ceramic, glass, metal, marble, or natural stone during the application process.

If the joints between the tiles are ⅛ inch or wider, look for an epoxy-based unsanded grout, which is extremely durable and better suited for larger joints. Keep in mind, however, that epoxy-based options are less pliable than the cementitious varieties and will generally be pricier.

For better staying power, finish vertical surfaces with unsanded grout.

The absence of sand, very low porosity, and a high polymer content makes unsanded grout especially sticky, so it will stay put when tiling a shower wall, backsplash, or other vertical surfaces where gravity can impact the grout.

Sanded grout, in comparison, is also more likely to slump when used on a vertical surface. And, since vertical installations don’t need to stand up to the pressure of foot traffic, they don’t need to have the strength qualities found in sanded grout.

sanded vs unsanded grout

Photo: yunava1 from Getty Images

Sanded grout should always be sealed, but does unsanded grout need to be sealed? The answer is yes. Whether you’re using the sanded or unsanded type, use a good grout sealer when the job is done and the grout is dry.

By sealing grout, you create a waterproof layer that prevents moisture from soaking into the grout and under the tiles. The grout absorbs the sealer, which then dries, preventing the grout from absorbing other liquids. All sanded and unsanded grouts should be sealed with the exception of epoxy-based grout, which is a waterproof grout.

Sanded grout is generally less expensive than unsanded grout.

A major difference between sanded and unsanded grout is price. Sanded grout is typically more than twice as expensive as unsanded grout. The cost difference between the two types has to do with the fact that sanded grout uses inexpensive sand as a filler, and unsanded grout uses more expensive polymers. For this reason, if budget is an issue and the project’s specs allow for it, sanded grout is the better option.

Both sanded and unsanded grout can be cleaned with degreaser and a stiff brush.

sanded vs unsanded grout

Photo: makasanaphoto

Whether you’re cleaning sanded grout or unsanded grout, the process is the same. You can use a grout cleaner or create your own grout cleaning paste by mixing 3/4-cup baking soda with a 1/4-cup of hydrogen peroxide and 1 tablespoon of mild dish soap. Apply the paste to the grout using a stiff grout brush and scrub, then rinse with water.

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