5 inch 5 520 square feet.
Calculate rain gutter size.
Determine the size of your downspout.
Then use the chart below to see what size gutter you need.
6 inch 7 960 square feet.
Find the width of the gutters.
For example a 5 inch gutter system requires at least 2 x 3 downspouts and a 6 inch gutter system requires 3 x 4 downspouts.
The code limit is 150mm for dp s and 26 800 sq mm for flat eaves gutters the program will calculate the size and number of downpipes downspouts leaders required and the eaves gutter sizes for any roof.
The total rainfall and how rapidly it falls will affect the runoff from the roof.
There is no limit to downpipe size or eaves gutter size.
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.
Then use the information below to see what size gutter you need.
Match your downspouts to the gutter size you chose in step 7.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
Gutters typically come in 5 or 6 in 13 or 15 cm sizes and can be k style or half round place a sturdy 20 ft 6 1 m ladder on 1 side of your house so that you can reach the gutters.
The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website.
The gutter and downspout size required is highly dependent on the amount of gutter and the spacing of the downspouts.
Adding additional downspouts will require less gutter and downspout volume resulting in smaller gutters downspouts.
5 inch 5 520 square feet.
Refer to the gutter packaging or specification for the recommended downspout size.
Calculations are based on level gutter capacity as experimentally determined by the national institute of standards and technology nist.
Simplified suitable for flattish roofs with little or no vertical faces or steep roofs draining to one side of box gutter only or any roof if you are in a hurry and make the necessary allowances for all catchments.
To limit the effects of thermal expansion in gutters 50 ft.
Gather some basic weather information to calculate the proper size for gutters and downspouts for a house.
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.
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.
Box gutter with rain water head at end of box gutter.
Please lower the maximum spacing between downspouts to see this effect.