Gutters
The 5-Inch vs. 6-Inch Question, Answered With Math
Gutter size isn’t a preference — it’s a calculation your roof already made. Here’s how sizing actually works, and why “what the builder used” is the wrong spec.
Gutter size isn’t a preference — it’s a calculation your roof already made. Here’s how sizing actually works, and why “what the builder used” is the wrong spec.
Three inputs: how much roof drains to each run (the drainage area), how fast it sheds (pitch — steep roofs deliver water like a firehose), and how hard it rains here (our region’s storm record answers that one loudly). A gutter is a channel with a flow rating; when the roof outruns it, water sheets over the back edge, straight down the fascia, and into the ground at your foundation.
Five-inch K-style is the default because it’s the cheapest line-item on a spec sheet — sized for average rain on an average roof. Northeast Wisconsin cloudbursts aren’t average, and neither is a big or steep roof. A 6-inch gutter carries roughly 40% more water than a 5-inch — the difference between a system working through a July downpour and a waterfall feature you didn’t order.
The gutter only holds water; downspouts move it. Undersized or too-few downspouts choke a big gutter down to small-gutter performance — which is why our estimates figure roughly one downspout per fifty feet of run, oversized where the drainage area demands it, discharging away from the foundation instead of beside it. Half the “my gutters overflow” calls we see are really downspout math.
We calculate it: your actual roof area and pitch against rainfall intensity, run by run — not a one-size default. Sometimes the honest answer is 5-inch is genuinely fine; big or steep sections get 6-inch and oversized outlets. Formed seamless on-site in your color either way, with the sizing math explained in plain English on your written quote.
Yes — and it’s often the smart spec. The steep back roof that dumps two planes into one run might need 6-inch while the porch stays 5-inch. Sizing run-by-run is exactly how it should be done.
They don’t cause or cure ice dams — dams are a roof-heat problem — but 6-inch gutters with a guard handle the freeze-melt cycle better and give ice fewer chances to wrench the system off the fascia. The dam fix itself lives on our ice dams page.
It’s a per-foot difference, not a different universe — and it’s on the written quote next to the 5-inch number so you can see exactly what the capacity costs. Our estimate machine prices your home’s footage instantly if you want the ballpark first.
Seamless gutter replacement and gutter protection for Northeast Wisconsin — storm-sized capacity, ice-country hanging, free quotes, financing available.
Back to the hub →A drop-in aluminum guard with one job — end the ladder routine for good. Properly installed, GutterRx carries a 20-year no-clog guarantee. Not "fewer clogs." No clogs.
Read more →A hooded aluminum cover that works on physics — water hugs the curve into the gutter, leaves slide past it to the ground. Lifetime no-clog warranty, in 16 colors that match your home instead of announcing themselves.
Read more →Seamless gutters price by the linear foot; guards price by the eave. Here are our real ranges — the same per-foot rates the estimate machine uses on your actual roofline.
Read more →The industry oversells them and skeptics overcorrect. The honest answer depends on your trees, your ladders, and your roofline — here’s the actual math.
Read more →Sectional gutters come in pieces and fail at the joints; seamless gutters are formed to your house in one run. In freeze-thaw country, that difference isn’t marketing — it’s physics.
Read more →Overflow has exactly four causes, and each one announces itself differently. Here’s how to read yours — and what actually fixes it instead of treating the symptom.
Read more →Everything starts online — you pick the path, we bring the crew.
Whatever brought you here — storm damage, a leak, or a roof that's due — it starts the same way: HomeIQ shows your real range and puts our inspection calendar in your hands. About two minutes.
Get My Estimate →We installed it and something's not right? Send photos and details — "Done right. Or we make it right." Covered warranty work costs you nothing.
Request Warranty Service →Free inspection. Firm written price. Financing available.