Sizing Downspout To Gutters

Use the downspout to redirect runoff and help prevent garden erosion and foundation damage.

Sizing downspout to gutters.

Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. More product details close. Size downspouts to fit the gutter. Offset of more than 10 ft 3 0 m can affect drainage capacity.

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. To limit the effects of thermal expansion in gutters 50 ft. You should have enough gutter downspouts to effectively handle the size of your entire gutter system.

5 inch 5 520 square feet. 6 inch 7 960 square feet. The larger a gutter downspout the more water it can drain quickly. 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.

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. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website. 15 m is a practical maximum gutter length to be served by a downspout. The downspout size must suit.

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. Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed. Downspouts should be constructed with conductor heads every 40 ft 12 2 m to admit air and prevent vacuum. 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.

They are made from aluminum vinyl zinc copper or stee l. Compatible with 2 in. A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour. If a roof s various drainage areas call for different size gutters go for the biggest one k style.

Most downspouts are rectangular but they can also be round or square. Then use the information below to see what size gutter you need. 5 inches and 6 inches gutters are the most common sizes installed for residential use. Then use the chart below to see what size gutter you need.

5 inch 5 520 square feet. Gutter downspout sizes are 3 to 6 inches. Metal or vinyl downspouts this versatile downspout has a lifetime guarantee. Downspout sizes must not exceed the bottom width of the gutter.

Doubling the number of downspouts halves the required capacity for each. The size of the downspout should be constant through out its length. If a roof s various drainage areas call for different size gutters go for the biggest one k style.