Grout is a strong cementitious mix or chemically-setting mix used for filling voids, joints, or cracks in concrete or masonry. There are two main categories of grout: cementitious grout and chemical grout. Cementitious grout has been used in the U.S. since the mid-1800's to create grouted reinforced masonry. This construction is normally used on buildings limited to a few stories. Cementitious grout is also used for embedding reinforcing bars, which increases the amount of load-bearing material in a masonry wall; for filling hollow metal door frames; for repairing cracks; and for connecting pre-cast concrete panels. Chemical grouts are fluid and are used for filling under the bearing plates of columns and machine bases or for injection to fill cracks. Grouts used for tiling, flooring, resin grout, flowable fill, stone restoration, and foundation and slab jacking are examples of more specialized grouts.

This topic includes information related to non-shrink grout used during construction. A hydraulic cement, non-shrink grout, is commonly used as a setting bed between structural members. The components of a non-shrink grout prevent loss of material volume or shrinkage, making it suitable for structural grouting.

This topic includes information related to epoxy grouting used during construction. Epoxy grout is a stable volume grout used between ceramic, porcelain and quarry tile. The material is impervious to water, stains and chemical reactions.