Dulwich Roofing · Homeowner guide
Signs Your Chimney Flashing Is Leaking (And How to Fix It)
Damp around a chimney can originate from flashing, masonry, top weathering or condensation in an unused flue. The location of the stain alone does not identify the failed part. A repair should follow a diagnosis of the complete stack and junction.
Clues to discuss with the roofer
- Does the damp appear during rain or persist regardless of weather?
- Are there visible splits, lifted edges or gaps at lead terminations?
- Have previous sealant or repointing repairs changed the symptoms?
Have the chimney and roof connection inspected together rather than replacing leadwork on assumption alone.
Avoid treating a junction as a surface
A durable junction depends on where water is directed, how materials overlap and how they move. Covering a visible split with sealant may not address those requirements. Ask whether the existing detail is fundamentally suitable or needs re-forming. Repairs should also consider adjoining mortar, brickwork and roof coverings so a new weathering detail is not undermined by a nearby defect.