Chimney flashing

A chimney is the most complex penetration on a residential roof — four sides, varying masonry, and movement at a different thermal rate than the roof deck around it. A proper flashing system is two-part: base flashing (sheet metal bent up against the chimney face and over the shingles) and counter-flashing (mortar-embedded metal that laps over the base). When either layer fails, water runs down the chimney chase and shows up as a stain on a wall or ceiling inside the house — often six to ten feet from the actual entry point.

On storm claims, chimney flashing damage is frequently claimable but frequently missed by adjusters who inspect from a distance. High winds loosen counter-flashing from eroded mortar joints. Hail can dent base metal and break the seal at step-flashing laps. We inspect every chimney from roof level on every job. Flashing that can be resealed gets resealed; flashing that is bent, torn, or corroded goes on the supplement as a replacement line item with photos of the failed condition.