6 inch 7 960 square feet.
Roof sqaure footage per area drain and dwonspout.
Roof drainage capacity for other roof drain pipe or leader diameters.
Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed.
Gutters come in a wide range of materials the cost depends on which you choose.
Calculate total roof area.
There are 5 easy steps to figure out how many drains your commercial roofing project will need.
5 inch 5 520 square feet.
A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour.
To do that simply multiply drainage area calculated earlier by roof pitch factor and rainfall intensity.
Doubling the number of downspouts halves the required capacity for each.
5 inch 2 500 square feet.
Max area of roof draining to one down.
According to the chart for 1 8 slope per 12 of pipe for 5 000 square feet of roof area with a 6 per hour of rainfall the required pipe size is 8.
6 inch 3 840 square feet.
Vinyl gutters cost 2 to 5 per linear foot.
After you have calculated the square footage use following calculations.
Calculate the total roof area by multiplying its length by width.
Plumbing codes typically use the vertically projected roof area for drainage design and they often use a square foot allowance per square inch of downspout for 1 in hr 25 mm hr rainfall that varies with diameter for example 3 in 76 mm.
Determine leader or pipe size.
Maximum horizontal projected roof area that can be drained in square feet.
We have rounded smith s data and comment further below.
Two hundred feet of gutter can cost anywhere between 660 and 4 500.
Adapted from smith 2014 cited below.
To size the vertical roof drain for the same parameters 5 000 square feet of room area and 6 per hour of rain consult table 1106 2 figure 3.
For most homes this means installing spouts at either end of a gutter section.
How many downspout installations should your gutters have.
A house in chicago has a roof whose actual drainage area is 1 000 square feet.
Metal gutters vary in price from 6 to 12 for aluminum and 9 to 20 for steel to 25 or more for high end copper.