Sizing Downspout To Gutters

You should have enough gutter downspouts to effectively handle the size of your entire gutter system.

Sizing downspout to gutters.

Gutter downspout sizes are 3 to 6 inches. More product details close. 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. If a roof s various drainage areas call for different size gutters go for the biggest one k style.

This durable downspout is maintenance free and has uv stabilizers to help prevent uv light degradation. Size downspouts to fit the gutter. 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 downspout size must suit.

The larger a gutter downspout the more water it can drain quickly. Most downspouts are rectangular but they can also be round or square. Compatible with 2 in. Gutters and gutter downspout sizes gutters are typically round shape or k style but other designs are available.

Then use the chart below to see what size gutter you need. Metal or vinyl downspouts this versatile downspout has a lifetime guarantee. 5 inches and 6 inches gutters are the most common sizes installed for residential use. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website.

If a roof s various drainage areas call for different size gutters go for the biggest one k style. 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. 5 inch 5 520 square feet. Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed.

Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. The size of the downspout should be constant through out its length. Then use the information below to see what size gutter you need. Use the downspout to redirect runoff and help prevent garden erosion and foundation damage.

Doubling the number of downspouts halves the required capacity for each. Offset of more than 10 ft 3 0 m can affect drainage capacity. To limit the effects of thermal expansion in gutters 50 ft. Downspout sizes must not exceed the bottom width of the gutter.

5 inch 5 520 square feet. A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour. They are made from aluminum vinyl zinc copper or stee l. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.

However too large a gutter downspout can look unattractive. 6 inch 7 960 square feet. The gutter outlet capacity should suit the downspout capacity.