This grout sealer is composed of silicon and seals your tile?s grout for better water resistance. Whether you?re considering your garden?s tiled birdbath or your shower, both need their grout protected from extreme moisture. This sealer provides excellent water protection and works against dirt penetration. Mold and mildew stains are not attractive in your bathroom or your birdbath. This easy-to-use silicon sealer will protect your grout from moisture damage inside and out.