Do gutter guards work in heavy rain?
Why heavy rain is the test
Georgia thunderstorms can drop rain at very high rates in short bursts. A roof concentrates all that water at the eaves, and valleys concentrate it even more at inside corners. A guard has to let water in as fast as it arrives. If it cannot, water sheets across the top and over the front.
How each type copes
- Stainless micro-mesh: high intake when clean; slows down when coated with pollen, oak tassels or sap, so a light brushing each spring matters.
- Perforated metal: handles heavy rain well when the holes are clear.
- Reverse curve: relies on water following a curved nose; in high flow, water can leap past it, especially on steep roofs.
- Screens: large openings take water well but clog with needles.
- Foam and brushes: water soaks through slowly once debris builds up.
Often the problem is not the guard
When a guarded gutter overflows, the cause is frequently the gutter itself: too narrow for the roof, too few downspouts, a clogged downspout, or poor pitch. Valleys that dump onto a short gutter run overflow with or without a guard, and a diverter or a larger downspout at that corner is often the fix.
Watch your gutters during the next real downpour. Where the water escapes, and whether it is crossing the guard or overflowing from inside the gutter, tells you which fix you need. More in gutter sizing, seamless gutters and guards and pine needles and leaves on your roof.