What is chimney repointing?
Repointing removes loose or failed mortar from the face of masonry joints and replaces it with a compatible new mortar. It is different from applying a thin surface smear, which can hide deterioration without creating a durable joint.
Signs repointing may be needed
- Mortar is recessed, cracked or missing
- Joint material powders when lightly touched
- Small fragments appear in gutters or on lower roofs
- Damp is associated with exposed stack faces
- Previous hard patching has failed around softer masonry
Compatibility matters
Mortar must suit the existing brickwork, exposure and construction. Excessively hard mortar can concentrate weathering in softer bricks. The correct specification should be chosen after inspecting the stack rather than solely from its age.
What a quotation should clarify
Ask which elevations and joints are included, how deeply failed mortar will be removed, whether bricks or flaunching also need repair, and what access system is allowed for. Photographic documentation makes the scope easier to verify.
Repointing will not solve every damp issue. If the joints appear sound, review chimney flashing and other possible sources in our leaking chimney guide.
Preparation and curing
Durability depends on preparation as much as the visible finish. Loose joint material must be removed to a sound depth without damaging brick edges, dust must be controlled, and the replacement mortar needs protection from rapid drying, heavy rain and frost while it cures. These requirements also influence timing and scaffold duration.
Repointing all faces
Weathering may be worse on one elevation, but access should allow the relevant faces to be inspected. A quotation should distinguish between local patch pointing, one complete face and full-stack repointing so the homeowner knows exactly what is included.
Ask about chimney repointing