Normal maintenance of masonry walls, assuming that there are no defects such as bulging or cracking, consists of pointing the joints—at intervals of decades rather than years. The wall must first be carefully prepared by removing loose mortar, raking out the joints to a depth of 12 to 15 mm and removing loose fragments and dust. If there is loose mortar to a greater depth caution should be exercised over the area to be raked—perhaps to about three courses of brickwork over a length of three stretchers. Before placing the mortar the joints should be wetted to prevent undue abstraction of water.