Formula To Calculate Gutter Size

Remember two gutter lengths can share the same downspout so if you calculate the max gutter to be 40 feet you could put a downspout halfway in an 80 foot length.

Formula to calculate gutter size.

Total roof area also affects runoff. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website. Gather some basic weather information to calculate the proper size for gutters and downspouts for a house. To limit the effects of thermal expansion in gutters 50 ft.

Roof length x half roof width x roof height 2 roof area. Minimum top opening width max. Then use the chart below to see what size gutter you need. Calculate the area of a roof to work out how much guttering is required.

Please lower the maximum spacing between downspouts to see this effect. Enter larger gutter widths in the yellow boxes to find out how wide your gutters need to be given the length that you want to go between downspouts. If a roof s various drainage areas call for different size gutters go for the biggest one k style. Water pipe size calculator information video water pipe size calculators size every pipe in your project in seconds with just 3 clicks.

The gutter and downspout size required is highly dependent on the amount of gutter and the spacing of the downspouts. The total rainfall and how rapidly it falls will affect the runoff from the roof. 6 inch 7 960 square feet. Calculate roof area to be drained by your gutter system and note roof pitches.

Then use the information below to see what size gutter you need. 5 inch 5 520 square feet. Adding additional downspouts will require less gutter and downspout volume resulting in smaller gutters downspouts. Downspout sizes must not exceed the bottom width of the gutter.

Gutter sizing step 4 calculate water handling capacity for gutter downspout options. There are two things you need to know. Overflow calculator for eaves gutters. Simplified app for android phones.

To calculate the effective roof area you should use this formula. Downpipe and eaves gutter calculator valley gutters generic rain water outlets for flat roofs. Commercial roof structures can be complex consisting of many areas shapes and configurations. An inch of rain is not much but it if falls in half an hour it could flood a gutter.

5 inch 5 520 square feet. Gutter sizing step 1 determine roof area to be drained. 15 m is a practical maximum gutter length to be served by a downspout. 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.

The simple way to calculate gutter sizes. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. If a roof s various drainage areas call for different size gutters go for the biggest one k style. 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.