repoint

Repointing means raking out old, failed mortar from between bricks or stones and packing fresh mortar into those joints. Over time, mortar deteriorates faster than the masonry units themselves. Rain, frost, and movement cause it to crack, crumble, and wash away, leaving gaps that admit water into the wall. Repointing restores the weatherproof seal and structural bond that keeps a wall sound.

The work begins with raking out the old mortar, typically to a depth of two to three times the joint width. Hand tools like plugging chisels and raking tools are standard; pneumatic tools speed the job but risk damaging soft brick or adjacent mortar. The joint is then damped (but not flooded), and new mortar is forced in with a pointing trowel, pressed hard to achieve good consolidation and bond. The surface is finished flush, recessed, or with a weathering bevel depending on the original profile and exposure.

Mortar matching matters

The new mortar must match the original in colour, texture, and crucially, composition and strength. Modern cement-rich mixes can be too hard and hydraulically aggressive; they may damage historic brickwork or stone. A softer, lime-based mortar is often required for older buildings. Testing the existing mortar and its bond strength helps specify the replacement correctly.

Repointing is labour-intensive and therefore expensive, which is why it is often postponed until obvious failure occurs. Condition surveys help identify which walls or elevations need it first. Exposure matters: north-facing, windward, and low-lying sections fail sooner. Architectural details, string courses, and chimney stacks are frequent trouble spots where standing water or movement accelerates decay.

The term comes directly from the noun pointing, the finishing of mortar joints. Repointing distinguishes renewal work from new pointing on freshly built brickwork. In some trades it is also called joint raking and filling or remortar, though the latter is less common in standard usage.