Most downspouts are rectangular but they can also be round or square.
Roof gutter sizes.
Half round gutter sizing is based on w 0 0182 la 2 5.
Downspouts also come in different sizes such as 2 3 inches and 3 4 inches in size.
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.
You should have enough gutter downspouts to effectively handle the size of your entire gutter system.
5 types of rain gutters to consider for your home find out if your home needs rain gutters and which materials are the most durable diy friendly and cost effective.
15 m is a practical maximum gutter length to be served by a downspout.
This is most common in the k style gutters.
Gutters come in different sizes.
To limit the effects of thermal expansion in gutters 50 ft.
5 inch 5 520 square feet.
Then use the chart below to see what size gutter you need.
Five inch k style gutters six inch half round.
I denotes rainfall intensity the roof area in square feet sq m.
There are two most common type of residential gutters that we will talk about in this post for reliable roof gutter sizing.
Half round 5 inch 2 500 square feet 6 inch 3 840 square feet.
Downspout sizes must not exceed the bottom width of the gutter.
However too large a gutter downspout can look unattractive.
If a roof s various drainage areas call for different size gutters go for the biggest one k style.
The downspout and gutter sizing calculator is located on the tools cad and apps page of the smacna website.
Gutter downspout sizes are 3 to 6 inches.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.
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.
For most homes this will be a large enough gutter to handle the amount of water washing off of the roof but if you live in a particularly rainy area you will want to opt for wider downspouts to be installed with your new gutters.
They can be 4 5 or 6 inches.
The larger a gutter downspout the more water it can drain quickly.