Why Are My Gutters Overflowing and What to Check First

Gutters Overflowing When It Rains: Likely Causes in Rochester, Ranked

1. Clogs of leaves and shingle grit in the trough or downspout.
2. Wrong pitch that holds water until it spills.
3. Bent or loose hangers that let sections sag.
4. Too little capacity. Many homes have 5 inch gutters. LawnStarter says 6 inch gutters hold up to 50 percent more.
5. Too few downspouts, which that source spaces 20 to 50 feet apart.

Rochester averages 34.27 inches of precipitation a year. August is the wettest month at 3.47 inches, per US Climate Data.

Gutters Overflowing in the Middle Points to a Sag or Low Spot

Watch from the ground. Overflow at one spot means a low point or clog there. Overflow at a corner means a blocked or small downspout, covered in our downspout guide.

Gutter pitch wrong: the bucket test

Pour a bucket at the high end, as Lee Company suggests. It should run to the downspout without pooling. Guidance is about a quarter inch of drop per 10 feet, per EngineerFix. Hangers sit about 4 feet apart.

Clogs by Tree Type and Debris, and Why Rochester Falls Hit Hard

Leaves, pine needles and shingle grit are the usual blockers, per LawnStarter, and Mr. Roof also lists twigs, plastic bags and shingle granules. Debris is the first thing to rule out, since it can overflow a gutter even in moderate rain.

How it packs depends on what drops. Broad leaves mat flat over the outlet. Needles slip through mesh and settle in the trough. Twigs and seed pods snag at the downspout elbow. Shingle grit sinks and hardens into a silt that holds water after the rain stops. Wet debris also holds moisture. That Gutter Helmet links to mold and corroded gutters.

Trim back what overhangs the roof

Cutting limbs that hang over the roof cuts the supply, as LawnStarter advises. Do it from the ground, and call a tree pro for anything near power lines.

Undersized Gutters, Too Few Downspouts and Roof Valley Splash

A gutter overflowing in heavy rain only is often a capacity limit. If a clean system still spills in light rain, capacity is likely the problem, according to LawnStarter. Lee Company notes that standard 5 inch K-style gutters may not handle torrential downpours. Gutter Helmet adds that a steeper roof sends water in faster. Sizing should be redone after a reroof. Installers do miscalculate.

Downspout count and spacing

Lee Company puts downspouts no closer than 20 feet and no farther apart than 50 feet. A long run with one outlet at the far end can overload that outlet. Match downspout size to the gutter, as Lee Company advises.

Where two roof planes meet

A valley gathers water from two slopes into one stream. So that stream can shoot past the gutter edge at the spot below it. Overflow that always appears under a valley is a splash problem, not a clog. Lee Company describes vinyl splash guards on gutter edges, with curved versions at corners where water moves fast. A pro can judge whether a guard or a bigger outlet suits your roof.

Loose Hangers, Fascia Rot and Rust Behind Overflow

Worn fasteners let a run tilt away from the house, Lee Company says. A tilted run spills. EngineerFix gives standard hanger spacing as every 4 feet and every 2 to 3 feet on long runs. That stops low spots from forming. Replace damaged brackets rather than adding screws to the same weak hole.

Overflow also does harm of its own. LawnStarter says a weak gutter connection to the fascia lets water splash under the eaves and rot the board. Standing water can invite mold. Mr. Roof lists water backing up behind siding and damage to interior walls and ceilings. Lee Company adds that aluminum and galvanized steel gutters rust over time. So a rusted-through trough that keeps leaking is a replacement conversation.

Tell leaks from overflow. Overflow is water splashing over the edge. Meanwhile, a leak is steady seepage from a hole or joint, per LawnStarter.

Ice, Snowmelt and Overflowing Gutters in Rochester Winters

Winter gutters overflowing are a different problem. Lee Company lists icicles on gutters, ice at the roof edge and water that overflows or will not drain as signs of an ice dam. Mr. Roof names ice dams as a result of overflow. Frozen leaves left in the trough make it worse. Clear gutters before cold snaps, as Lee Company advises.

Staying safe matters more than a quick fix. Do not climb an icy ladder or roof. Never chip ice with a hammer, chisel or any tool, because shingles and gutters crack easily. Lee Company suggests a roof rake from the ground. It also suggests attic insulation and ventilation to even out roof temperatures. Our ice dam guide covers the rest.

Safe Checks, Then When to Stop and Call

1. Stand back in steady rain and note where water spills.
2. Look for sags and pulled hangers.
3. Check each downspout outlet is running.
4. Do the bucket test from a stable, low position.
5. Look for stains, soft fascia or soil washed out below the eave.
6. Note whether it spills in light rain or only in heavy rain.

Many cases need only a ground-level look and a hose. Stop and call for two-story roofs, ice or wet ladders. Call for nearby power lines or any sag you cannot explain. Never chip ice with tools. A clog needs a clean-out. A sag needs re-hanging. Undersized or rusted runs may mean replacement. See gutter repair and downspout cleaning and repair.

Rain Overflow in Rochester NY: Gutter Cleaning Rochester Can Take a Look

Gutter Cleaning Rochester serves Rochester NY and nearby Monroe County. See gutter repair and downspout fixes. You can also check the areas we cover or our Rochester gutter cleaning home page.

Sources and further reading

• usclimatedata.com: Usny1232
• leecompany.com: 7 gutter problems and how to fix them
• wxxinews.org: Cleanup continues after record setting rain