While the tiles themselves are usually the star of a tiling project, equally important is what goes between them: the grout.  

Grout is a vital component of any tiling job, and selecting the right one can be a complex process with multiple factors to consider. There are practical considerations such as the sizes of your grout joints, where the tile is being installed, and how you want the grout to look next to the tile. It is important to choose the right grout based on all these factors to ensure the grout does not damage the tile, that it stands up to the environment around it, and that it adds to the aesthetics of your space in just the right way.  

In this article, we will help you navigate all of these factors to help you find the right grout for your tiling project.  

Understanding Grout Types

The vastness of options for tile materials requires a wide variety of types of grout. There are many factors to consider, such as the size of the gaps between the tiles, the tile material, and the environment where the tile is being installed. For residential installations, cement-based grout is the most common choice.  

Cement-Based Grout

Cement-based (cementitious) grout is the most common type of grout and can be used for just about any tiling project in your home. It's easy to work with and comes in a variety of colors. To keep it looking its best, cement-based grout should be sealed periodically.    

Cement-based grout comes in sanded and unsanded varieties. The type you choose will depend on a few factors.

Sanded Grout

Sanded grout is best for joints of 1/8 in. or larger. The sand gives sanded grout a grittiness that can help improve traction when used on floors and gives extra stability when installing heavier tiles on walls. This exceptional strength also means sanded grout offers superior resistance to shrinking and cracking. It is best for grouting porcelain, ceramic, and rough stone tiles such as slate and travertine.  

Unsanded Grout

Unsanded grout is a non-abrasive version of cement-based grout. Although it still finishes quite strong, the lack of sand to reinforce its hold means unsanded grout is best for joints that are under 1/8 in. It is also ideal for use with tile materials that are likely to scratch easily, such as metal, marble, and glass. The absence of sand also means this grout will finish smoothly, giving a clean, polished look.

Other Grouts

Although cement-based grouts are the most common, they are far from the only option. There are multiple options for specific use cases where cement-based grout will not work well.

Epoxy Grout

Epoxy grout is the best choice for tiling projects that will be exposed to high amounts of water, such as swimming pools. While most professionals will use cement-based grout for a shower, that grout will require frequent re-sealing, which may make epoxy grout a better choice for ease of maintenance.  

Keep in mind, however, that epoxy grout will have a higher upfront cost and some homeowners may think the finished product looks plasticky compared to cement-based grout. It also dries more quickly than cement-based grout, which can make it more challenging for a DIYer to work with, so you should plan to hire a professional to apply epoxy grout.

Furan Resin Grout

Furan resin grout is a specialized type of grout designed to stand up to harsh chemicals. This makes it a good choice for industrial facilities, laboratories, and food production plants. It is rarely used in residential tiling projects because it is significantly more expensive than standard cement-based grout, less aesthetically appealing, and requires a high level of skill to work with.  

Ready-to-use Grout

One way to simplify the grouting process is to opt for ready-to-use grout. As the name implies, this grout comes pre-mixed and is ready to apply right out of the container. This offers many advantages, especially for less experienced DIYers, including color consistency throughout the project and no need to seal the grout when you're finished.  

But this convenience comes at a price, as ready-to-use grout will generally be more expensive than grout that requires mixing. It will also take longer to cure than dry grout and is not recommended for large format tiles, natural stone, or in high-moisture areas.

Choosing Grout Based on Tile Type

While most residential tiling jobs will call for cement-based grout, you will still need to understand which type of grout is right for your project. It is important to consider the tile size and material, planned layout, and whether the tile is being installed on the wall or on the floor.

Ceramic and Porcelain Tiles

Ceramic and porcelain are the most popular tile materials, and they are typically paired with the most popular grout: cement. Cement-based grout can be easier to apply compared to epoxy grout, which is the other most common type used for these tiles. It is also more affordable and maintains its color for longer. But remember: when using cement-based grout, be sure to use sanded grout for large format tile and on joints 1/8 inch or larger, and use unsanded grout for softer material tiles and for joints smaller than 1/8 inch.  

That said, it is also worth considering epoxy grout for your ceramic or porcelain tiling project.

Epoxy grout is resistant to staining and mildew growth--all without sealing. This makes it a good candidate for kitchens, mudrooms and bathroom tile projects. It is also typically stronger than traditional cement-based grout. This makes epoxy grout a good choice if you value a highly durable, low-maintenance grout in an environment that is otherwise likely to require frequent cleaning.

Natural Stone Tile

Natural stone tile comprises a wide variety of surface textures, so there is no one-size-fits-all grout recommendation. Instead, you need to consider the characteristics of your preferred natural stone material to ensure you pick the proper grout.  

For porous stone tiles, such as marble, you should go with an unsanded grout. The sand from sanded grout can collect in the pores of these tiles, which will lead to deep, unsightly scratches during and after the grout application process. If you intend to use large format tiles or plan to have grout lines over 1/8 inch, you can seal the tile before applying the grout to avoid abrasion.  

Rough, unpolished natural stone tiles, such as pebble stone or limestone, can be installed with either sanded or unsanded grout. The only consideration for these materials is the width of the joints: for joints under 1/8 inch, go with unsanded. For joints over 1/8 inch, use sanded grout. (A notable exception to this rule: slate tiles. Because of their texture, we recommend using sanded grout only with this unpolished natural stone, regardless of the width of your grout joints.) 

Glass Tiles

The inherent translucence of glass tiles means the grout lines will appear more prominent. This also makes it especially important that they not be scratched during the grouting process, as the scratches will be easily visible and may require the tile to be replaced. You can use either unsanded cement-based grout or epoxy grout for your glass tiles.  

Unsanded cement-based grout offers a smooth finish, and epoxy grout finishes even smoother, which can be an excellent complement to the smooth glass tiles. It will also prevent mildew growth and provide significant water resistance, which is ideal if you are installing the glass tiles in a shower or tub surround. However, it is generally more expensive than unsanded cement-based grout.  

You may also want to consider ready-to-use unsanded grout for your glass tile project. It is generally more affordable and easier to apply than epoxy grout and is not susceptible to yellowing as epoxy can be. However, ready-to-use grout will not be as resistant to direct exposure to moisture in areas such as showers, laundry rooms, and entryways, so it is better suited to areas away from a direct water source, such as kitchen backsplashes or accent walls. 

Grout Color Considerations

After you have taken the time to select the perfect tile for your project, you should be sure to select the perfect grout color for your tile. There are two approaches to choosing grout color: matching and contrasting.  

Matching Grout to Tile Color

Applying grout that matches the color of the tile is a great way to create a seamless, modern look on walls and floors. This approach also has the benefit of making your space feel larger, since the definition of the tiles is de-emphasized. A less prominent grout line can be especially helpful if you are installing smaller tiles over a large area or if you want to emphasize a continuous, slab-like visual with large-format tiles.  

With lighter color tile, matching the grout and tile colors can also up the brightness factor in the space, making it feel airier and cleaner. For darker tiles, using a matching dark grout masks the separation between the tiles, making the surface feel even more grounding, which can be a benefit when installing tile in a large space.  

For tile surfaces with more than one color, such as multi-color mosaics or stone tile, try matching the grout to the most prominent color. This will help the grout blend into the background so that the tile is the star.    

One important thing to remember is to keep up with cleaning your grout if it is prone to getting dirty. If dirt, grease, or other messes are allowed to accumulate, all the hard work you put into matching the color of the grout to the color of the tile will have been in vain, as the dirty grout lines will start to become discolored and more apparent. 

Contrasting Grout to Tile Color

For a bold, dramatic look, consider going with a grout color that contrasts with your tile color. One classic combination is white subway tile paired with black grout: this look is full of visual interest and makes the space feel intentional and vibrant.  

But diametrically opposed colors are not the only option: you may also consider coordinating the grout with another visual element in the room, such as the wall color, furniture, or some other prominent visual element.  

No matter how you choose to contrast, it's important to make sure the difference in color is significant. A slight contrast can sometimes come off as dirty-looking or muddle the effect you are after. When in doubt, as a tile expert for guidance.

Grout Maintenance

Grout maintenance is more than making sure it looks its best. Yes, keeping your grout clean will help ensure it does not become discolored, but it will also prevent mold and mildew from developing and will keep the bond with the tile strong.  

The care your grout requires will depend on where it is installed. Grout in high moisture areas needs regular wiping down to prevent damage from excessive water exposure, whereas grout installed on a backsplash or accent wall will only require the occasional dusting every few weeks with a spot clean here or there as needed.

Water Resistance

No matter what surface your grout is on, it's a good idea to make sure it is able to stand up to water. Epoxy grout is non-porous, so it can withstand direct, sustained exposure to moisture without any extra care.  

Cement-based grout, on the other hand, is not naturally water resistant, so it is important to seal it regularly as recommended by the manufacturer's instructions, even if it is not used in high-moisture areas like showers or tub surrounds.

Stain Resistance & Treatment

The porosity of cement-based grout means it is at risk of staining if not properly maintained. For both sanded and unsanded cement-based grout, regular sealing is required to prevent spills from seeping in and staining the grout.  

If your grout does happen to become stained, you can use a grout colorant to restore the desired color. The application process for grout colorant can sometimes pose a threat to materials like natural stone, so be sure to read the manufacturer's instructions and be careful when applying it. 

Durability

When choosing grout, you should consider the durability requirements of the area where it is being applied. For grout applied to floor tiles, opt for a grout that can stand up to heavy foot traffic, which will typically be a sanded grout applied into grout joints of 1/8 in. or larger. If you are grouting pool tiles, epoxy grout is your best bet for preventing breakdown and cracking. Before installing any grout, consult the manufacturer's instructions and be sure its durability is appropriate for your specific application.

Grout Joint Size and Application

The grout joint is the space between each tile. While very small mosaic tiles will usually come on a mesh backing, most tiles are typically installed one at a time and need to be manually spaced using tile spacers. This requires some consideration about what size the joints should be, which will depend on factors both practical and aesthetic.

Narrow vs. Wide Grout Joints

The size of the grout joint will depend on the type of tile, where it is being installed (floor or wall), and aesthetic preferences.  

Smaller grout joints are suitable for smaller tiles that are common in less demanding environments such as kitchen backsplashes or accent walls. Grout lines as small as 1/16 in. help emphasize the uniformity of smaller tiles and can help create a seamless look. When grouting joints this small, it is best to use an unsanded grout, since it is smoother and much better suited for fitting into very small joints.  

Handmade and handmade-look tiles will typically look neater with a larger grout joint of 1/8 in. or larger, because this will help blend together size inconsistencies. However, you can also opt for a smaller joint for handmade or handmade-look tiles if you want to emphasize a rough, DIY look.  

Larger floor tile will require wider grout lines (1/8 in. or larger) to accommodate the slight shifting that all flooring material experiences without breaking the grout. For grout lines of this size, it is recommended that you use a sanded grout. The sand reinforces the strength of the grout, preventing it from cracking or separating from the tile.

Flexible Grout for Movement

The sturdiness of grout is usually considered a desirable asset, since that rigidity keeps the tile firmly in place and prevents it from chipping or cracking. But on some surfaces, a little flexibility is needed to prevent the grout from breaking. For those instances, we recommend you use a flexible polymer grout.  

Polymer grout is designed to allow a little give when tiles shift. This is especially important for tile layouts with especially large joints, when tile is installed over a particularly large area such as the floor in an open floor plan room, or when the surface will experience more extreme heat and moisture conditions. Polymer grout is available in both sanded and unsanded, so you can apply the precise type of grout your job requires without sacrificing flexibility.  

For changes of plane, such as corners, edges, and expansion joints, you may want to opt for something even more flexible such as caulk or a silicone sealant. While it may not be suitable for grouting the entire area, both caulk and silicone will provide the flexibility these areas need. Look for a color-coordinating caulk that will blend with the grout used in nearby areas. 

Resources for Expert Installation & Grout Care

Ready to grout? Read on for all the resources you'll need to approach your grouting project with confidence.  

Grout Like a Pro

Our grouting experts have put together a guide specifically for grouting projects. You can refer to this step-by-step tutorial, How to Grout Like a Pro, for everything you need to know to complete your grouting project.

Cleaning and Maintaining Grout

Keeping your grout looking its best and preventing the growth of mold and mildew while maintaining its strength requires special care. Although it is generally a simple process, it does require specific instructions to prevent damaging the grout. Our tile experts have put together a comprehensive guide on how to clean grout that will help you keep your tile surface free from discoloration and germs.

Repairing Grout

Even the most fastidious grout care can result in cracked or discolored grout. In those instances, you may decide it's time to regrout your tile surface. Our tile experts have put together a guide on how to regrout tile, which will take you step by step through the process of repairing your grout.

Conclusion

Your choice of grout has nearly as many factors to consider as your choice of tile. The type of grout, whether or not it is sanded, the size of your tile, the size of the joints, the color and its performance requirements are all important to weigh when choosing the right grout for your project. If you are uncertain about which grout is right for you, our tile experts are available to help you navigate each of these variables and will help you pinpoint the precise grout for your project.  

And remember, regular maintenance is the key to keeping your grout strong and vibrant.

Choosing Grout FAQs

Can I use the same grout for walls and floors?

Yes, it is possible to use the same grout for walls and floors. However, the considerations for when to use which type of grout will vary between each application. Floor tiles will typically require the enhanced durability afforded by sanded grout, which is also the grout of choice for heavier tiles applied to walls.  

However, you should not try to simplify your supply list by purchasing one type of grout for floor and wall tiles without consideration for each tile's needs. For example, a large format floor tile and mosaic glass wall tile will require different types of grout, and trying to save money by using the same grout for both projects will only result in one needing to be redone.

How long should I wait before walking on newly grouted floors?

The amount of time you need to wait before walking on newly grouted floors will depend on the manufacturer's recommendation. Usually freshly grouted floors are fine to walk on after 24 hours. For heavy traffic areas, you may need to wait as long as 48 to 72 hours to prevent damaging the grout.  

Some grouts are formulated to be ready to walk on in significantly less time. For example, Superior Excel Sanded Grout is "walk on" ready within four hours. Always follow the manufacturer's instructions when calculating how long to let it set.  

Can I change the grout color after it’s been applied?

Yes, in some cases it is possible to change the color of grout after it has been applied using topical methods such as a grout pen and grout colorants.  

The simplest way to change the color of your grout is with a grout pen, which is a tool you use to paint a coat of coloring over the top of your existing grout. This only works when the paint closely matches the original color of the grout, so it is not a good solution for drastic color changes. It is also not a suitable replacement for cleaning grout, because it does not kill bacteria, mold or mildew; it will simply cover them up.  

For a deeper and more permanent change, you can use a grout colorant. The colorant can be applied carefully using a polybrush to work it into the joints. For best results, apply two coats.  

However, not all grout can be changed to any color. The process of changing grout color only works when going from a lighter color to a similar color or to darker color. If you want to change from a dark grout to a light color, you will need to remove the old grout and apply new grout in your preferred shade.

Related Content: How to Regrout Bathroom Tile in 7 Easy Steps

What's the difference between sanded and unsanded grout?

The difference between sanded and unsanded grout is the presence of actual particles of sand in cement-based grout. Sand provides extra strength and durability to the grout, which is a necessity for joints that are 1/8 or larger. Sanded grout also provides additional holding strength for large and heavy tiles being installed on walls.  

But with that added strength comes added coarseness, which means sanded grout should not be used with tiles made of delicate materials such as glass or marble. For those tiles, unsanded grout will provide the strength necessary to keep the tiles in place without risk of abrasion. Unsanded grout is also ideal for any type of tile with a joint less than 1/8 inch because its finer texture is easier to work into the joint compared to sanded grout.

Do I need to seal my grout?

We highly recommend sealing your grout, especially if it is cement-based, and/or likely to be exposed to any sort of moisture, dirt, or anything else that might stain it. Even wall-mounted tile can benefit from the grout being sealed, because the ambient humidity and risk of splashing or spilling means unsealed grout on your walls will be vulnerable to stains.  

Sealing your grout helps prevent stains, damage from moisture, and mildew growth. This will keep your grout lines looking fresh and clean for longer and will make cleaning them a much simpler process.

Can I use grout on outdoor tile installations?

Yes, grout is necessary wherever tile is installed, including in outdoor installations. However, it is important to make sure you select a grout that is specified for outdoor use such as Superior Excel or Ardex X3 Plus grout. If the grout was not designed to withstand extreme weather conditions such as extreme temperature and moisture fluctuations, it will break down and your tiles are more likely to be damaged.

How do I clean grout that has become discolored?

Discolored grout can be cleaned in a few ways. The most effective way to clean it is by using a specialized grout cleaner. These products are specially formulated to be gentle on tile while also being tough on grout discoloration. Follow the manufacturer's instructions to ensure the best results.  

There are other approaches that make use of materials you may have around your house, such as vinegar, oxygen bleach, or a paste of 1/2 cup baking soda, 1/4 cup hydrogen peroxide, and 1 tablespoon of dish soap. Solutions using vinegar or oxygen bleach can be highly effective, but they should be used sparingly, as they can cause the grout to degrade if used with even slight regularity. The paste will be the gentlest on your grout.  

Once the desired color has been restored, you should plan to regularly clean and seal your grout. This will prevent future discoloration and will extend the life of your grout.

Is it necessary to use grout between tiles?

Yes, it is always necessary to use grout between tiles. For starters, a tile installation without grout will simply look messy and incomplete, with large gaps showing the mortar on the wall behind the tile or the floor under it. But perhaps more importantly, grout is key to keeping the tile in place and protecting it from chips and cracks. It also helps prevent moisture from getting under the tile and developing mold and damaging the wall or subfloor.  

Grout also makes tile floors more comfortable to walk on since there will be no risk of scraping toes on bare tile edges.  

Can I install grout myself, or do I need a professional?

Installing grout is a moderately challenging project for DIYers, but it is one that many find satisfying. It requires attention to detail and the right tools, but it can be accomplished by anyone with sufficient diligence and patience.  

If you have a complex project or you feel unsure of your ability to get it done right the first time, it is probably best to hire a professional to ensure the grout is applied properly. But if you're ready to get started on a grouting project, we have a step by step guide on how to install grout like a pro to help you along your way. 

When should I use silicone or caulk instead of grout?

Grout, silicone sealant, and caulk are all used in certain circumstances to fill gaps between tiles. For the spaces between the tiles themselves, grout is usually the right choice. But for places where extra flexibility is required to accommodate normal movement or expansion of tile and other surfaces, caulk or silicone are the best choice. Using grout in these places can lead to cracking, which can allow moisture to penetrate the tile and form mold or mildew, ultimately damaging the substrate.  

Silicone sealant and caulk are recommended for areas around sinks, tubs, and showers where the tile meets the bathroom fixture. These materials provide a flexible, watertight seal that is vital in areas frequently exposed to high moisture because they are highly effective at keeping water from seeping behind the tile.