How to size gutters downspouts 1.
How to size gutters.
You ll also need to.
Spout drains up to 600 sq.
Make sure the ladder extends at least three feet.
Get 7 or 8 inch gutters.
Ft and a 3 in.
See photos below most residential gutters will measure approximately 5 inches across the top with the actual opening being approximately 4 5 inches.
How do you do the math to figure out how large your gutters should be.
Gutters come in different sizes.
Set up an extension ladder against one edge of your home s roof.
You have three options.
Increase the pitch of the gutter.
Area and flow in table 1 4 are based on 1 in 25 mm of rainfall per hour.
Find the width of the gutters.
How do you calculate gutter size.
Per ft and you can multiply the watershed by 1 4.
A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour.
Each square inch of downspout cross section can drain 100 sq.
They ll cost more and probably require a custom order through a professional installer.
What size gutters do you need.
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.
Divide these areas by the local rain fall rate in inches per hour to determine the actual roof area to be served by the gutter diameter.
Adjusting for pitch and rainfall.
Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed.
Gutters come in different sizes.
Increasing the pitch increases a gutter s.
Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted.
Downspouts also come in.
Spout drains 1 200 sq.
Pitch your gutters by 1 8 in.
Carefully climb up the ladder and measure the width of the opening at the top of the gutters.
Measure your gutter across the top from the back where the gutter meets the home to the outer edge.
Consider your drainage area.
Place the torpedo level on the roof with the level body sitting perpendicular to the roof peak.
The steeper a roof s pitch the more windblown rain it can collect.
Calculate your roof.
This determines the maximum watershed level gutters can serve between downspouts.
Size downspouts to fit the gutter.
They can be 4 5 or 6 inches.
From chart 1 2 it is determined that a 9 5 in 241 mm half round gutter should be used.
Measure the length and.
