Roof Area Per Downspout

Calculate total roof area.

Roof area per downspout.

Size downspouts to fit the gutter. Then use the information below to see what size gutter you need. More product details close. Calculate the total roof area by multiplying its length by width.

The minimum downspout size is min. Given the area factor b in table 10c the design area is design area plan area x b 1600 x 1 05 1680 sf. The more roof surface above the gutters the more rainwater will be caught and funneled down into those gutters. A large roof is going to move a lot of water which means the downspout locations may need to be adjust to compensate.

This should be considered when connecting gutters and downspouts. Multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. This durable downspout is maintenance free and has uv stabilizers to help prevent uv light degradation. 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 a roof s various drainage areas call for different size gutters go for the biggest one k style. This wizard makes it easy to calculate the roof design area by providing various shape calculations and the calculation for vertical walls area per international plumbing code ipc. Rainfall intensity should always be checked with the local authorities. Gutters and downspouts are vulnerable for obstructions caused branches and leafs from surrounding trees and similar.

Welcome to gutter supply your online reference for gutters gutter machines gutter guards and accessories. Smacna s new downspout and gutter sizing calculator enables the user to manually enter the design area of the roof or use the design area wizard for the calculation. 5 inch 5 520 square feet. Determine leader or pipe size.

There are 5 easy steps to figure out how many drains your commercial roofing project will need. Metal or vinyl downspouts this versatile downspout has a lifetime guarantee. Intensity lasting calculated roof area intensity lasting calculated roof area 5 minutes drained per 5 minutes drained per downspout area downspout area in hr mm hr sq ft sq m in hr mm hr sq ft sq m sq in 100 sq mm sq in 100 sq mm 7 4 187 160 2 30 10 4 265 110 1 70 7 1 181 170 2 40 9 9 251 120 1 70 1 8 46 660 9 50 3 1 77 390 5 70. Come visit our selection of quality products.

The roof plan area that is drained by each downspout is plan area 40 x 40 1600 sf. Compatible with 2 in. Use the downspout to redirect runoff and help prevent garden erosion and foundation damage. From table 10a column b2 the area drained per square inch of downspout is 130 sf.

Doubling the number of downspouts halves the required capacity for each.