How Many Downspouts Does a House Need?
Updated
Short answer
An average home needs four to five downspouts, about one every 30 to 40 feet of gutter, each 10 to 15 feet long (HomeGuide).
Why the count matters
Every downspout drains a share of the roof. By USGS arithmetic, one inch of rain on 1,000 square feet of roof is about 623 gallons. Split a 2,000 square foot roof between two downspouts and each has to move about 620 gallons per inch of rain; split it among five and it is about 250. In a summer downpour, the house with too few downspouts overflows first.
Signs you need another one
- A long run that overflows at the far end even when clean.
- Water sheeting off an inside corner where two roof planes dump into one gutter.
- Undersized 2 by 3 inch downspouts on an older house that clog every season.
Adding or replacing downspouts: HomeGuide lists replacement at $30 to $75 per downspout. See downspout repair and extensions.
Quick answers
How far apart should downspouts be?
HomeGuide's guide uses about one downspout every 30 to 40 feet of gutter.
Rather have someone else do it?
Tell us the address, how tall the house is and what you need. A local crew calls back with a price before anything is booked.