Grout is the mortar that fills the joint spaces between floor and wall tiles, brick, and other masonry work. Grouting is performed after the tile has been laid with thinset or mastic and is the final step for locking the tile into place. Grout is available in a wide variety colors and can be mixed with other additives to achieve better stain resistance, increased strength, or other properties.
Choosing the best type of grout for your installation will depend on the style and color of the tile, the size of the joint spaces, and where the tile installation is located. There are both cement-based grouts and epoxy grouts. The cement-based grouts are available as sanded and non-sanded.
Non-Sanded Grout is a cement-based grout that does not contain any sand. It is typically used for smaller tile joints that are 1/16th to 1/8th inch wide. It should not be used for larger joints because as the grout cures, it shrinks. With wider joints, more grout is need to fill the space, but the more grout that is used, the more shrinkage that occurs. In wide joints, the grout can crack due to the lack of bonding strength or can even pull away from the tile if the joint is large enough.
Non-sanded grout is often used with ceramic tile, glass tile, polished marble, and other easily scratched materials because it will not scratch the surface like sanded grout might. When using these types of materials with larger grout joints, an epoxy grout is often a better choice. Because non-sanded grout tends to be stickier than sanded grout, it works well for vertical applications such as shower walls. It is also easier on the hands than sanded grout.
Available in either dry powdered form or premixed, non-sanded grout is applied with a grout float and sponge. Once fully cured, non-sanded grout becomes very hard like concrete. The grout, however, is still very porous and should be sealed with a good quality penetrating sealer to help prevent stains and dirt from entering into the pores of the grout.
Sanded grout is the most common type of cement-based grout. As the name suggests, sanded grout has fine grains of sand added to it. The addition of the sand helps prevent the grout from shrinking too much as it cures, allowing it to be used for grout joints that are larger than 1/8th inch wide. Additionally, many sanded grouts will also have a mixture of polymers already added for increased strength and flexibility.
While sanded grout is used for wider grout joints, it can become problematic for certain materials including polished marble, travertine, and other polished stone. The sand in the grout can scratch polished surfaces as the grout is wiped over the material during the grouting process. For these situations, an epoxy grout is often the best way to go.
Epoxy grout has increasingly become more popular among tile installers and contractors. Unlike typical cement-based grout, epoxy grout is a two-part system composed of an epoxy resin and hardener. Without the addition of water, the two components are mixed together to form the epoxy grout. In some cases, such as with Laticrete SpectraLOCK, a third, color powder component, is also added to the epoxy grout mix.
Epoxy grout offers several advantages over cement-based grouts. Once cured, epoxy grout is extremely hard and durable, and because the epoxy is non-porous, it offers superior stain and water resistance. The high stain, chemical, and water resistance properties make epoxy grout easy to clean and an excellent choice for bathrooms, showers, kitchens, commercial applications, and anywhere that is prone to stains, mildew, mold, and contact with water. Additionally, the non-porous nature of epoxy grout means that a penetrating sealer is not required for stain resistance. Most premium epoxy grouts will also offer consistent color.
While there many advantages to using epoxy grout over cement-based grout, there are also some disadvantages. Typically, epoxy grout is more difficult to work with than traditional grout. It has a faster cure time, tends to be stickier, and can be harder to work into the grout joints. There may also be sag in vertical installations. Epoxy grout can also have a plastic appearance that may not be ascetically pleasing to everyone.