Sizing Downspout To Gutters

Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed.

Sizing downspout to gutters.

Then use the chart below to see what size gutter you need. 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. Gutter downspout sizes are 3 to 6 inches. To limit the effects of thermal expansion in gutters 50 ft.

Most downspouts are rectangular but they can also be round or square. 15 m is a practical maximum gutter length to be served by a downspout. If a roof s various drainage areas call for different size gutters go for the biggest one k style. 5 inch 5 520 square feet.

Now that we are well aware of the various gutter downspout sizes and styles let us dig deeper into the materials used for effective downspouts and how much they shall cost. More product details close. 5 inch 5 520 square feet. The larger a gutter downspout the more water it can drain quickly.

Size downspouts to fit the gutter. Doubling the number of downspouts halves the required capacity for each. They are made from aluminum vinyl zinc copper or stee l. 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.

Compatible with 2 in. 5 inches and 6 inches gutters are the most common sizes installed for residential use. A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour. Metal or vinyl downspouts this versatile downspout has a lifetime guarantee.

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. Then use the information below to see what size gutter you need. The downspout size must suit. You should have enough gutter downspouts to effectively handle the size of your entire gutter system.

Downspout sizes must not exceed the bottom width of the gutter. The size of the downspout should be constant through out its length. Offset of more than 10 ft 3 0 m can affect drainage capacity. If a roof s various drainage areas call for different size gutters go for the biggest one k style.

Gutters and gutter downspout sizes gutters are typically round shape or k style but other designs are available. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website. This durable downspout is maintenance free and has uv stabilizers to help prevent uv light degradation. Use the downspout to redirect runoff and help prevent garden erosion and foundation damage.

However too large a gutter downspout can look unattractive. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. 6 inch 7 960 square feet.