Cracking in buildings normally results from restrained movement. This movement may originate within a building material due to temperature change or shrinkage; or may result from movement of adjacent building elements. In most cases, movement is inevitable and must be accounted for during design if cracking is to be controlled. Control joints placed in concrete masonry walls are one method of crack control. Control joints are vertical separations built into a concrete masonry wall to reduce restraint and permit longitudinal movement. They are located where cracking is likely to occur due to excessive tensile stress.
