Use the chart below to figure out how many extra downspouts you need.
Calculate how many downspouts gutters need.
Doubling the number of downspouts halves the required capacity for each.
One 3x4 downspout will drain 1200 sq.
Now architects engineers designers and contractors can easily and accurately size downspouts and gutters according to the specifications in smacna s architectural sheet metal manual 7th edition 2012.
In terms of material options most seamless gutters roughly 80 of all installs are made from aluminum.
Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed.
Of gutters and downspouts you will be spending about 1 500 1 800.
Elbows miters end caps gutter outlets gutter wedges gutter offsets coil sheet goods gutter hangers downspout brackets gutter flashings gutter fasteners conductor leader heads aluminum soffit trim gutter decorations downspout guards accessories paint sealant solder polish tile.
Size downspouts to fit the gutter.
3 by 4 inches 1 200 square.
A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour.
Adding a 2 by 3 rectangular downspout for instance boosts your gutter s capacity by 600 square feet of drainage area.
So if you need to install 150 ln ft.
Particularly wet climates could require better drainage systems than relatively dry climates rainy.
Keeping gutters in good condition is more important than many people realize.
Aluminum is the most popular choice for gutter material because it s lightweight and durable.
Rectangular 2 by 3 inches 600 square feet 3 by 4 inches 1 200.
Prices range from 6 12 per linear foot for both gutters and downspouts.
Large gutters can hold more water and may not need as many spouts.
Gutters come in many sizes.
As with gutters a downspout s capacity must match or exceed the expected runoff.
As with gutters a downspout s capacity must match or exceed the expected runoff.
Smaller gutters may need extra downspouts to make up for their low volume.
Not only can runoff from a roof ruin landscaping next to a building it may cause erosion that will damage the foundation.
2 by 3 inches 600 square feet.
The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website.
On average two hundred feet of gutter and 50 feet of downspout will cost approximately 2250.
Use the chart below to figure out how many extra downspouts you need.
3200 square feet of roof is calculated as 3200 600 5 33 rounding up you would need 6 2x3 downspouts or 3200 square feet of roof is calculated as 3200 1200 2 67 rounding up you would need 3 3x4 downspouts one 2x3 downspout will drain 600 sq.
Adding a 2 by 3 rectangular downspout for instance boosts your gutter s capacity by 600 square feet of drainage area.
Cost of aluminum gutters and downspouts.
Cost of vinyl gutters and downspouts.
