Gutter slope and downspout layout — pitch to the downspouts, crown long runs
Gutters slope ~¼″ per 10 ft toward the downspouts (a long run crowns in the middle and falls both ways). Plan about one downspout per 30–40 ft — plus more wherever the roof area exceeds the gutter’s capacity.
What this diagram shows
An elevation of a gutter run along the eave. The gutter is not level: it pitches about a quarter inch per 10 feet toward a downspout so water drains instead of pooling. A long run is crowned at a high point in the middle and slopes both ways to a downspout at each end. Plan roughly one downspout for every 30 to 40 feet of run, and add another wherever the roof area feeding the run is more than the gutter size can drain.
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