The gutter and downspout size required is highly dependent on the amount of gutter and the spacing of the downspouts.
Gutter size irc.
If a roof s various drainage areas call for different size gutters go for the biggest one k style.
Maximum rainfall conditions will be used to determine downspout size ï it is decided to drain the building with 4 downspouts located at each corner of the building.
102 mm in width and shall direct water away from the vertical sidewall onto the roof and or into the gutter.
International residential code 2012 irc 2012.
Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed.
The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures.
Then use the information below to see what size gutter you need.
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 a depth to width ratio of at least 0 75.
To limit the effects of thermal expansion in gutters 50 ft.
Where siding is provided on the vertical sidewall the vertical.
If a roof s various drainage areas call for different size gutters go for the biggest one k style.
A standard 5 inch k style gutter can handle annual rainfall for a majority of houses in most of the u s.
15 m is a practical maximum gutter length to be served by a downspout.
Overflow drains having the same size as the roof drains shall be installed with the inlet flow line located 2 inches.
Please lower the maximum spacing between downspouts to see this effect.
A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process.
Then use the chart below to see what size gutter you need.
5 inch 5 520 square feet.
6 inch 7 960 square feet.
You can also add additional or oversized downspouts to improve drainage if necessary.
Box gutters are offered in colored kynar material 0 032 aluminum and 24 gauge galvanized steel 24 gauge galvalume plus 0 027 regular standard aluminum colors and in copper both 16 oz and 20 oz.
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.
5 inch 5 520 square feet.
These gutters are commonly seen in commercial and industrial applications but are also used in homes for a more clean and modern look.
