Calculate Size Of Gutters

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.

Calculate size of gutters.

When you are completing a gutter replacement the first point to note is that gutters come in different sizes. 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. 5 inch 5 520 square feet.

You only need a ladder chalk tape measure level paper and pen. Total roof area also affects runoff. Gather some basic weather information to calculate the proper size for gutters and downspouts for a house. Downpipe and eaves gutter calculator valley gutters generic rain water outlets for flat roofs.

Adding additional downspouts will require less gutter and downspout volume resulting in smaller gutters downspouts. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. Simplified app for android phones. An inch of rain is not much but it if falls in half an hour it could flood a gutter.

Downspout sizes must not exceed the bottom width of the gutter. Overflow calculator for eaves gutters. If a roof s various drainage areas call for different size gutters go for the biggest one k style. To choose the right size gutters for a building that doesn t already have them you can quickly calculate the drainage area of the roof and adjust for pitch and rainfall to find the adjusted square footage.

The total rainfall and how rapidly it falls will affect the runoff from the roof. Then use the information below to see what size gutter you need. 15 m is a practical maximum gutter length to be served by a downspout. Downspouts also come in different sizes such as 2 3 inches and 3 4 inches in size.

So for a roof that is 5 m long with a height of 4 m and the roof width is 8 m which makes the half roof width 4m we can calculate the effective roof area like this. If a roof s various drainage areas call for different size gutters go for the biggest one k style. Please lower the maximum spacing between downspouts to see this effect. The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website.

They can be 4 5 or 6 inches. 6 inch 7 960 square feet. Then use the chart below to see what size gutter you need. To limit the effects of thermal expansion in gutters 50 ft.

The gutter and downspout size required is highly dependent on the amount of gutter and the spacing of the downspouts.