Formula To Calculate Gutter Size

Downspout sizes must not exceed the bottom width of the gutter.

Formula to calculate gutter size.

So for a roof that is 5 m long with a height of 4 m and the. Overflow calculator for eaves gutters. The simple way to calculate gutter sizes. 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. Roof length x half roof width x roof height 2 roof area. 5 inch 5 520 square feet. Gather some basic weather information to calculate the proper size for gutters and downspouts for a house.

Minimum top opening width max. 5 inch 5 520 square feet. Calculate roof area to be drained by your gutter system and note roof pitches. Simplified app for android phones.

Total roof area also affects runoff. The total rainfall and how rapidly it falls will affect the runoff from the roof. Gutter sizing step 4 calculate water handling capacity for gutter downspout options. 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. Gutter sizing step 1 determine roof area to be drained. 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. 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.

Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. Calculate the area of a roof to work out how much guttering is required. To calculate the effective roof area you should use this formula. Adding additional downspouts will require less gutter and downspout volume resulting in smaller gutters downspouts.

15 m is a practical maximum gutter length to be served by a downspout. Downpipe and eaves gutter calculator valley gutters generic rain water outlets for flat roofs. Then use the information below to see what size gutter you need. The gutter and downspout size required is highly dependent on the amount of gutter and the spacing of the downspouts.

Please lower the maximum spacing between downspouts to see this effect. If a roof s various drainage areas call for different size gutters go for the biggest one k style. To limit the effects of thermal expansion in gutters 50 ft. There are two things you need to know.

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 and gutter sizing calculator is located on the tools cad and apps page of the smacna website. 6 inch 7 960 square feet. Then use the chart below to see what size gutter you need.