How far should a metal roof overhang the drip edge?
Why the overhang matters
Water clings to the underside of metal and will curl back along it if the edge stops flush. A short overhang gives it a clean place to drip. Too little and water wicks back onto the eave trim, the fascia and the back of the gutter. Too much and the unsupported panel ends can flutter in wind, sag over time, and overshoot the gutter in heavy rain.
Eaves vs rakes
- Eaves. Eave trim or drip edge goes on first, underlayment laps over it, then panels run past it by the amount the manufacturer's detail shows. Exposed-fastener panels usually sit on foam closures at the eave so wind-driven rain and insects cannot get up into the ribs.
- Standing seam. Panels are often hemmed and hooked onto a continuous cleat or the eave trim, so the overhang is set by the trim profile rather than measured by eye.
- Rakes. The panel is cut or bent to stop inside a rake trim that wraps the edge. A panel sticking out past the gable is a wind uplift point.
Gutters change the target
With gutters, aim for the drip line to land over the inside half of the gutter. Fast-moving water off a steep, slick metal roof can jump a gutter during Georgia downpours, so some roofs need a gutter set slightly lower, a larger gutter, or a diverter at valleys.
See how edge metal works in drip edge explained, the broader pros and cons in metal roofing in Georgia, and gutter sizing in gutter sizing and seamless gutters.