Why is my metal roof leaking?
Short answer. Metal roofs usually leak at fasteners with worn washers, at panel laps, at trim and closures, or around penetrations, and the pattern of the leak points to which one. Leaks in any rain suggest fasteners or penetrations, leaks only in wind-driven rain suggest laps, ridge or wall trim, and dripping on cool, dry mornings is condensation.
Read the pattern
- Every rain, steady drip in one spot: a fastener, a pipe boot, or a rust hole above it.
- Only with wind from one direction: ridge closures, rake trim or sidewall flashing on that side, or side laps.
- Long, slow rains on low slopes: end and side laps, where water lingers and wicks in.
- Cool mornings with no rain, spread over a wide area: condensation on the underside of the panels.
- New leaks after a hot spell: fasteners worked loose by expansion and contraction.
Where to look on the roof
- Fasteners along the line above the leak: cracked, missing or crushed washers, and backed-out screws.
- Laps: gaps in the sealant tape or loose stitching screws.
- Trim: ridge closures, rake trim and wall flashing.
- Penetrations: boots and curbs.
- The eave: gutters backing water up under the eave trim.
The roof type matters
Exposed fastener panels, common on porches, barns and some homes, need periodic fastener maintenance by design. Standing seam roofs with concealed clips rarely leak at fasteners but can leak at trim, penetrations and damaged seams.