Repointing (or simply pointing) is the process of repairing the mortar between masonry units in masonry construction. Over time, weathering and decay can cause voids in the mortar joints between brick or stone allowing the undesirable entry of water. Water entering through these voids has the possibility of causing significant damage through a freeze/thaw process. Removing any deteriorated mortar joints and replacing it with fresh mortar will extend the life of your chimney and prevent any costly water related damage to the chimney system.