Gutter Sizing Roof Slope Factor

Then use the information below to see what size gutter you need.

Gutter sizing roof slope factor.

Then use the chart below to see what size gutter you need. Multiply the surface area by the pitch factor to find the rain collection area for your roof and you can buy the right size guttering. 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. An expansion joint will be installed in each gutter between the downspouts.

In plastic k style 5 inch guttering will drain up to 5520 ft 6 inch up to 7960 ft. 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. Locate the roof pitch slope factor for the pitch of your roof by consulting a roof pitch chart or using the following values. Since the slope is 6 in ft 152 mm m factor 1 10 is used table 1 1 making the design area 9350 sq ft 868 sq m.

The steeper a roof s pitch the more windblown rain it can collect. Water will run off faster from a very steep roof than from one with a gradual slope. If a roof s various drainage areas call for different size gutters go for the biggest one. Total roof area also affects runoff.

Sizing the gutters multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage. Adding additional downspouts will require less gutter and downspout volume resulting in smaller gutters downspouts. The gutter and downspout size required is highly dependent on the amount of gutter and the spacing of the downspouts. If a roof s various drainage areas call for different size gutters go for the biggest one.

In half round the capacities are 2500ft for 5 inch and for 6 inch 3840ft. Hold one end of the level against the roof level it and then measure the distance between the roof and the underside of the level at its midpoint which. For roofs between flat and 3 in 12 in pitch use a factor of 1. A roof of 1 200 square feet in size will collect more water than one that is 600 square feet.

Pitch or steepness also is a factor. The plan area of this building is 8500 sq ft 790 sq m. Maximum rainfall conditions will be used to determine downspout size ï it is decided to drain the building with 4 downspouts located at each corner of the building. Sizing the gutters multiply the drainage area by the roof pitch factor and rainfall intensity to find out the adjusted square footage.

Please lower the maximum spacing between downspouts to see this effect. You can measure pitch with a 2 foot level and a tape measure. The building is 100 x 85 ft 30 5 x 26 m with a double pitched roof having a slope of 6 in ft 152 mm m ï the slope is toward the 100 ft 30 5m side.