How To Size Roof Storm Drains

Ipc provides four steps to size the roof drains on a building.

How to size roof storm drains.

And 4 area handled by each drain. 2 total area of roof. 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. To convert to an area for a 4 inch per hour rainfall to enter table 1108 1 do this.

1 rate of precipitation. 2 total area of roof. For drain areas between two opposite walls add no additional area. For larger roof drains the pipe may be smaller such as a 10 in.

Roof drain connected to a 6 in. Each vertical drain must carry 2 500 sq ft of roof area at 3 75 inches per hour of rainfall. A minimum 4 inch vertical drain is required. Each 4 drain size in a 6 hourly rainfall area will accommodate drainage of 3 070 sq.

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. 2 500 4 x 3 75 2 344 sq ft. If the area of each wall is not the same add 50 percent of the difference between the two areas. And 4 area handled by each drain.

3 size of leader required. For example a 4 in. Roof drain connected to an 8 in. The four things you will need to know are.

The four things you will need to know are. Calculate total roof area. 1 rate of precipitation. Or less in diameter the piping will be larger in diameter than the roof drain.

3 size of leader required. Enter table 1108 1 until you find a diameter pipe that will carry 2 344 sq ft. Determine leader or pipe size. 2 3 4 5 6.

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. For horizontal pipes or leaders receiving two or more roof drains. Calculate the total roof area by multiplying its length by width. Following this logic it is possible that for roof drains 6 in.

2 3 4 5 6 and 8 in. Zurn makes it easy to size roof drains. 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.