repointing

Repointing is the process of renewing the pointing (the external part of mortar joints) in masonry construction. Over time, weathering and decay cause voids in the joints between masonry units (usually bricks), allowing the undesirable entrance of water. Water entering through these voids can cause significant damage through frost weathering and from salt dissolution and deposition. Repointing is also called pointing, or pointing up, although these terms more properly refer to the finishing step in new construction.