This type is most commonly used for ceramic, porcelain, stone and glass tile installations where the joints are 1/8-inch wide or larger. Sanded grout helps support the weight of the installation. It is weaker than epoxy-based grouts but stronger than unsanded cement grouts. After drying, which takes approximately 24 hours, these grouts are as hard as cement. The main drawback, however, is that sanded grout absorbs water, which can ultimately cause cracking.
To create latex-modified sanded grout, latex polymer is included as an ingredient in the dry mix used to make grout. Acrylics are also included in the mix. The polymer may also be added during the mixing process. Some manufacturers also include anti-fungal and mildew resistance properties to latex-enhanced grout. Latex adds strength and improves color retention in tinted grouts, but most important, it decreases water absorption. Even with latex additives, however, cement-based grouts will continue to retain water, thus sealants should be applied.
Caulking grouts are silicone-based sealants available in caulking guns or in tubes that may be squeezed by hand. They are used to seal joints between adjacent surfaces such as tile and a wall, tub, shower, kitchen sink, counter tiles and the 90-degree corners where tile meets tile. Silicone caulking grouts are manufactured in colors close, or identical to, sanded grouts.
These are applied over sanded and unsanded cement grouts to prevent absorption of water or other liquids. Silicone grout sealants not only prevent water from leeching into the grout, causing it to crack, they also prevent staining from other substances. Seal also helps protect the substrate of the floor or wall from water damage. At least two days or as long as two weeks must pass between the time tile and grout is installed and the time that silicone sealant may be applied. This time frame allows grout to cure properly. Before applying silicone sealant, clean tile and grout to prevent dirt from being sealed into the grout. Apply sealant with a brush at least every two years to keep grout looking new.