What is repointing?
Repointing is the process of removing deteriorated mortar from between bricks or stone and replacing it with new mortar to restore the joint and weathertightness of masonry.
When mortar joints in brick or stone masonry fail, they no longer seal out water and weather. Repointing is the selective removal and replacement of that failed mortar without disturbing the masonry units themselves. This targeted approach stops water infiltration, restores structural integrity at the joints, and prevents damage to the units themselves.
Old mortar fails for several reasons. Lime-based mortar from older buildings hardens over decades and becomes brittle. Freeze-thaw cycles in Connecticut's winters crack and disintegrate mortar. Water penetration dissolves the binder. Salt migration pulls moisture into joints. Wind-driven rain and ground salts accelerate breakdown, especially in chimneys, foundations, and parapets exposed to weather.
Repointing differs from tuckpointing in method and finish. Tuckpointing involves cutting out failed mortar and filling the joint with a matching base mortar, then adding a thin contrasting mortar line down the center for visual effect. Repointing simply removes old mortar and refills the full joint flush or slightly recessed with new mortar matched to the original.
Repointing also differs from full rebuilding. A masonry rebuild removes and replaces damaged units along with the mortar, tackling bricks or stone that have spalled or crumbled. Repointing addresses the joints alone when units are sound. An experienced masonry contractor can assess whether a wall needs repointing, tuckpointing, or more extensive work.