Chimney stack defects
The chimney is the most exposed masonry on the building and the hardest thing to inspect without scaffolding. It is also, along with flashings, one of the most common sources of persistent damp in an upstairs room.
What it looks like from above
- Open joints and washed-out pointing on the exposed faces
- Spalled or flaking brick faces where frost has got into the masonry
- A cracked or missing flaunching around the base of the pots
- A stack that is visibly out of plumb, or pots that are cracked or displaced
What happens if it's left
- Water soaks into the stack and shows as damp on the chimney breast inside
- Loose masonry and pots are a falling risk onto the roof and the ground
- Left long enough, repointing becomes a full rebuild of the stack
How it's normally fixed
Repointing in an appropriate mortar, renewing the flaunching, replacing damaged pots, and re-dressing the flashing where the stack meets the roof. A leaning stack needs a rebuild rather than a patch.
Common questions
How often does a chimney need repointing?
Typically every 20 to 30 years in Scotland, sooner on exposed properties. The exposed windward face usually goes first.
Can a drone inspect a chimney properly?
Yes — a drone can photograph all four faces and the pots from a few metres away, which is normally only possible with scaffolding.
Think you've got this on your roof?
We photograph every elevation, circle each defect and grade it by severity — £99 residential, £149 commercial, report within 24 hours.