How To Size Roof Storm Drains

Enter table 1108 1 until you find a diameter pipe that will carry 2 344 sq ft.

How to size roof storm drains.

If the area of each wall is not the same add 50 percent of the difference between the two areas. For multiple walls use 50 percent of the maximum projected area of all walls. For example a 4 in. Step by step instructions step 1.

Select a reference of a roof drain size with hourly rainfall together with the roof area square footage you have estimated and then determine from the chart below how many roof drains you require. For drain areas between two opposite walls add no additional area. Determine leader or pipe size. Roof drain connected to a 6 in.

Determine 100 year 1 hour rainfall rate used for location of building select number of roof drains and calculate the roof area sloped to each drain size horizontal storm drainage piping size vertical storm drainage piping. The four things you will need to know are. Each vertical drain must carry 2 500 sq ft of roof area at 3 75 inches per hour of rainfall. Sizing data for conventional drainage storm drainage sizing precipitation rate inches hour based on 15 minute precipitation zurn makes it easy to size roof drains.

2 500 4 x 3 75 2 344 sq ft. When sizing roof drains the limiting factor for the amount of water each drain will carry away is the size of leader therefore increasing leader size decreases the number of drains required. And 4 area handled by each drain. Ipc provides four steps to size the roof drains on a building.

Calculate total roof area. Roof drain connected to an 8 in. The four things you will need to know are. 2 total area of roof.

Following this logic it is possible that for roof drains 6 in. 2 3 4 5 6 and 8 in. 3 size of leader required. To convert to an area for a 4 inch per hour rainfall to enter table 1108 1 do this.

2 total area of roof. And 4 area handled by each drain. A minimum 4 inch vertical drain is required. Or less in diameter the piping will be larger in diameter than the roof drain.

For horizontal pipes or leaders receiving two or more roof drains. 1 rate of precipitation. Roof drainage 2016 05 11 plumbing advanced drainage systems sizing a gravity pipe work water surface pros for storm sewers sizing a gravity pipe work four s to sizing roof drains c1scapacities of sewer pipespipe sizing charts tables energy modelsdrain and sewer pipe size home owners workfour s to sizing roof drains c1scapacities of sewer. Calculate the total roof area by multiplying its length by width.

1 rate of precipitation. 3 size of leader required. Zurn makes it easy to size roof drains.