Block Jointing Mortar is a specialized mortar used for bonding and filling the joints between masonry blocks, such as concrete blocks, AAC (Autoclaved Aerated Concrete) blocks, or clay bricks.

It is primarily designed for the construction of walls, where it helps to hold the blocks together while providing a strong, durable joint. Block jointing mortar is often used in place of traditional cement-sand mortar for improved efficiency, speed, and performance.