Rain Water Gutter Size

Adding additional sections of gutter reduces the length of each section and will reduce the gutter size.

Rain water gutter size.

Unless special provisions are made for flexibility in downspouts rain gutters and their support systems gutters should expand away from downspouts and downspouts should not be located near gutter expansion joints. See photos below most residential gutters will measure approximately 5 inches across the top with the actual opening being approximately 4 5 inches. Also the gutter width in relation to height may also be adjusted. If a roof s various drainage areas call for different size gutters go for the biggest one k style.

You should have enough gutter downspouts to effectively handle the size of your entire gutter system. 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 15 3 m is a practical maximum length of gutter to be served by a downspout.

The gutter and downspout size requirement depends upon the number of sections and length of the gutter sections as well as the number of downspouts. Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed. 5 inch 5 520 square feet. Measure your gutter across the top from the back where the gutter meets the home to the outer edge.

Use this handy guide to make sure your rain collection is up to the task during even the heaviest storm. Most downspouts are rectangular but they can also be round or square. 6 inch 7 960 square feet. Doubling the number of downspouts halves the required capacity for each.

Five inch k style gutters or 6 inch half rounds the most common residential sizes are able to handle the rainfall on most houses in most parts of the country. Size downspouts to fit the gutter. A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour. But houses with big steep roofs or those located in climates prone to heavy downpours may need wider gutters and extra downspouts to keep rainwater from overflowing.