How To Size Roof Storm Drains

2 total area of roof.

How to size roof storm drains.

Determine leader or pipe size. Roof drain connected to an 8 in. Each 4 drain size in a 6 hourly rainfall area will accommodate drainage of 3 070 sq. Zurn makes it easy to size roof drains.

The four things you will need to know are. Step by step instructions step 1. The four things you will need to know are. Calculate the total roof area by multiplying its length by width.

For drain areas between two opposite walls add no additional area. 2 3 4 5 6. 2 total area of roof. 1 rate of precipitation.

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. Or less in diameter the piping will be larger in diameter than the roof drain. 1 rate of precipitation. Ipc provides four steps to size the roof drains on a building.

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

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

For horizontal pipes or leaders receiving two or more roof drains. And 4 area handled by each drain. For larger roof drains the pipe may be smaller such as a 10 in. 2 500 4 x 3 75 2 344 sq ft.

3 size of leader required. 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. A minimum 4 inch vertical drain is required. For multiple walls use 50 percent of the maximum projected area of all walls.

And 4 area handled by each drain. Each vertical drain must carry 2 500 sq ft of roof area at 3 75 inches per hour of rainfall. For example a 4 in.