What is roof flashing?
Sheet metal installed at roof joints, penetrations, and edges to direct water away and prevent leaks at vulnerable points where water naturally collects.
Flashing is sheet metal (typically aluminum, galvanized steel, or copper) installed to seal the gaps where roof planes meet walls, chimneys, vents, skylights, and other structures. It directs water away from seams and penetrations where water intrusion is most likely to occur. Without proper flashing, these junction points become entry points for leaks that damage interior framing and insulation.
Common locations for flashing include the junction where the roof meets an exterior wall, around chimney bases, at roof valleys where two slopes meet, along eaves and gutters, and around plumbing vents and HVAC penetrations. Each application requires specific flashing angles and overlaps to ensure water sheds downward and outward rather than pooling or running underneath shingles or roofing material.
Flashing typically lasts 15 to 20 years depending on material and weather exposure, though ice dams, rust, or improper installation can shorten its lifespan. Rust stains, water marks on interior ceilings near seams, or visible deterioration are signs flashing needs replacement. Proper installation and maintenance of flashing are critical to roof durability. Connecticut contractors who perform roof repair work routinely address flashing as part of leak remediation and seasonal inspections.