Over time, the mortar in brick joints naturally cracks and deteriorates leaving mortar joints weakened and open.  This not only detracts from the aesthetics of your building but it detracts from the structural integrity of it as well.  The process of repairing a mortar joint in a brick wall is called "tuckpointing." The term comes from the process of tucking mortar into the damaged mortar joint with the point of a trowel called a "pointing trowel." Tuckpointing is a critical maintenance task and keeps water from entering the brick wall cavity. If water is allowed to get past the mortar and into the wall, brick failure may occur such as cracking or spalling (popping off of the brick face).