Sizing Downspout To Gutters

6 inch 7 960 square feet.

Sizing downspout to gutters. A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour. Gutter downspout sizes are 3 to 6 inches. If a roof s various drainage areas call for different size gutters go for the biggest one k style. Size downspouts to fit the gutter.

Compatible with 2 in. The downspout size must suit. The capacity of a sloped rectangular gutter may be approximated by using a gutter cross section area not less than that of a semicircular gutter and. The gutter outlet capacity should suit the downspout capacity.

You should have enough gutter downspouts to effectively handle the size of your entire gutter system. 5 inches and 6 inches gutters are the most common sizes installed for residential use. They are made from aluminum vinyl zinc copper or stee l. 15 m is a practical maximum gutter length to be served by a downspout.

Then use the information below to see what size gutter you need. The size of the downspout should be constant through out its length. Downspouts should be constructed with conductor heads every 40 ft 12 2 m to admit air and prevent vacuum. The second most common style of downspouts in urban homes is the rectangular downspout coming under a range of sizes such as 2 3 3 4 and 4 5.

To limit the effects of thermal expansion in gutters 50 ft. However too large a gutter downspout can look unattractive. Most downspouts are rectangular but they can also be round or square. Gutters and gutter downspout sizes gutters are typically round shape or k style but other designs are available.

More product details close. Offset of more than 10 ft 3 0 m can affect drainage capacity. Downspout sizes must not exceed the bottom width of the gutter. 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.

Doubling the number of downspouts halves the required capacity for each. This durable downspout is maintenance free and has uv stabilizers to help prevent uv light degradation. Then use the chart below to see what size gutter you need. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website.

Metal or vinyl downspouts this versatile downspout has a lifetime guarantee. If a roof s various drainage areas call for different size gutters go for the biggest one k style. The larger a gutter downspout the more water it can drain quickly. Use the downspout to redirect runoff and help prevent garden erosion and foundation damage.

5 inch 5 520 square feet. 5 inch 5 520 square feet. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.