Gutters Overflowing in Heavy Rain: Clog, Slope or Size?
Gutters overflowing in heavy rain in Bloomington, IL come down to one of three causes: a clog, a bad slope, or gutters too small for the roof. Telling them apart matters because the fix is different for each. With the wettest months of May, June and July averaging 4.36, 4.09 and 3.99 inches at the Bloomington station, a gutter that overflows is a gutter not doing its one job during the heaviest rain of the year.
The Short Answer
If the overflow is at one spot, it points to a clog or a low spot in the run. If it is over the whole length, the gutter is likely undersized for the roof or pitched wrong end to end. Check the clog first, because it is the most common and the cheapest to fix. Then look at slope and size.
Cause One: A Clog
A clog is the first thing to check because it is the most common. When needles, leaves and shingle grit pack the trough or block the downspout, water backs up and spills over the front edge in a hard rain. The tell is water pouring over one section while the rest of the run stays dry, and a downspout that runs weak or dry when it should be gushing. The fix is a full cleaning: scoop the trough by hand and flush every downspout until it runs clear.
Cause Two: Wrong Slope
Wrong slope sends water to a low spot instead of the downspout. A gutter needs a slight, steady pitch toward its outlets, and when a run sags in the middle or was hung level, water pools there and overflows even when the trough is clean. The tell is standing water sitting in the gutter a day after the rain stops, always in the same spot. The fix is re-pitching the run on hidden hangers so it drains to the downspout. See gutter repair in Bloomington for how re-pitching is done.
Cause Three: Undersized Gutters
Undersized gutters overflow along the whole run no matter how clean or well-pitched they are. A 5-inch gutter on a large or steep roof simply cannot carry the volume a hard Bloomington storm throws at it, because one inch of rain drops about 623 gallons on 1,000 square feet of roof. The tell is uniform overflow across the length during heavy rain, with a trough that is clean and draining otherwise. The fix is upsizing to 6-inch gutters and 3x4 downspouts. See seamless gutter installation in Bloomington.
How to Diagnose It Yourself
Diagnosing it takes one rainy-day look and one dry-day look. First, during a hard rain, watch where the water spills, whether at one spot or along the whole run. Second, check whether the downspouts gush or trickle. Third, the day after, look for standing water and where it sits. Finally, note the gutter size and roof pitch. One-spot overflow with a weak downspout is a clog, standing water in one place is slope, and uniform overflow on a big roof is size.
Frequently Asked Questions
Why do my gutters overflow even though they look clean?
Gutters that overflow while looking clean have a slope or size problem, not a clog. If water pools in one spot and sits after the rain, the run has sagged or was hung level and needs re-pitching. If the overflow runs along the whole length during heavy rain, the gutters are likely too small for the roof, since a 5-inch trough cannot carry what a large or steep roof sheds in a hard storm. The downspout may also be clogged below the visible trough.
Can heavy rain overwhelm a clean, well-sized gutter?
A correctly sized, clean, well-pitched gutter handles normal Bloomington rain, including the four-inch-average wet months, without overflowing. Brief overflow in an extreme cloudburst can happen to any system, but repeated overflow in ordinary heavy rain points to a real problem: a clog, a low spot, or undersized gutters. If a clean, 6-inch system with clear downspouts still overflows regularly, the number or placement of downspouts is worth checking.
Is overflowing water bad for the foundation?
Overflowing water is bad for the foundation because it dumps the roof's runoff straight down against the wall. One inch of rain puts about 623 gallons on 1,000 square feet of roof, and an overflowing gutter sends that volume into the soil at the base of the house instead of out through the downspout. The soaked ground then pushes water through foundation cracks and the floor-wall seam, which is a common path to a wet basement.
Call Now for Gutter Cleaning in Bloomington, IL
If your gutters overflow every storm, call 123-456-7890 to reach a gutter cleaner in Bloomington, IL.