The process of repairing a mortar joint in a brick wall is traditionally 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).
Unlike masonry walls, chimneys are exposed to the effects of wind, snow, ice, and rain from the four sides of the chimney and top. They are therefore subject to a continuous war of expansion and contraction due to the chimney masonry being heated by hot gases from the fire, and the cold, wet outdoor temperatures. This repetitive expansion and contraction creates a lot of movement, and consequently deterioration.
Have your chimney inspected periodically. Once a chimney begins to deteriorate, that deterioration grows rapidly if left unrepaired. Left untouched, deterioration can lead to brick replacement or complete rebuild of the chimney.
Caulking refers to the application of flexible sealing compounds used to close up gaps in buildings and other structures against water, air, dust and insects. Caulking seals the joints between masonry and other non-masonry surfaces by blocking against moisture. Doherty Tuckpointing uses only professional grade caulk for all projects around windows and doors, expansion joints and concrete.
All loose and deteriorating caulk is properly removed before new sealant is applied to ensure watertight seal.