Grout is a versatile composite material that is used in construction to fill gaps and seal openings in surfaces. The basic elements of grout are cement, water, and sand, making it similar to mortar, which can also be used with other binding agents besides cement. While grout is most commonly associated with tiling, where it is used to fill the gaps between tiles, it has other applications as well.

Grout is an excellent filling material that is used to firm and reinforce the installation of building materials that have inherent voids, such as hollow concrete blocks. Grout is also used for the installation of rebar for reinforcement of block-based walls, ensuring that the metal rods are permanently set. While grout has numerous applications, the composition of the grout differs depending on the application. Tile grout, floor grout, and structural grout are all slightly different in composition.