Use the chart below to figure out how many extra downspouts you need.
How many downspouts for gutters.
For especially long gutter runs of 40 feet or more the slope or pitch should start in the middle diverting the water to a downspout at each end.
How many downspout installations should your gutters have.
For most homes this means installing spouts at either end of a gutter section.
2 by 3 inches 600 square feet.
The number of additional downspouts needed to increase the gutters capacity will depend on the size of the downspout.
When you look at a rain gutter system from the ground it looks like it was parallel to the roofline of the house but they are slightly inclined so rainwater can flow straight to the downspout without problems.
The incline should be approximately one inch for every sixteen feet.
On average two hundred feet of gutter and 50 feet of downspout will cost approximately 2250.
Doubling the number of downspouts halves the required capacity for each.
Use the chart below to figure out how many extra downspouts you need.
3 by 4 inches 1 200 square feet.
As with gutters a downspout s capacity must match or exceed the expected runoff.
This is a critical aspect in any rain gutter installation.
The number of downspouts can be determined by the surface square feet of your roof.
The next factor to take into account is the pitch of your roof because the pitch will cause water to flow in a certain direction.
First you must consider how many downspouts you will need.
Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed.
There are many more important factors that can change this broad rule.
For example adding one 4 inch round downspout will increase the gutter.
The highest tip of the guttering should gently slope downwards to end at the downspout.
Adding a 2 by 3 rectangular downspout for instance boosts your gutter s capacity by 600 square feet of drainage area.
Once you add up the square footage of your roof you can then determine the number of downspouts.
Rectangular 2 by 3 inches 600 square feet 3 by 4 inches 1 200 square feet.
Adding a 2 by 3 rectangular downspout for instance boosts your gutter s capacity by 600 square feet of drainage area.
A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour.
If we have to sum it up in a single rule gutters need a downspout around every 30 to 40 feet.
3200 square feet of roof is calculated as 3200 600 5 33 rounding up you would need 6 2x3 downspouts.
As with gutters a downspout s capacity must match or exceed the expected runoff.
Prices range from 6 12 per linear foot for both gutters and downspouts.
