How To Size Roof Leader Collection Pipe Size

Determine 100 year 1 hour rainfall rate used for location of building.

How to size roof leader collection pipe size.

The first step in sizing a roof drain is to calculate the surface area of the roof that the drains will be covering as well as the average hourly rainfall rate at the building location. Step by step sizing of zurn drains. Table 1106 2 storm drain pipe sizing for si. 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.

The next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout. Calculate total roof area. Size vertical storm drainage piping. 1 rate of precipitation.

Select number of roof drains and calculate the roof area sloped to each drain. 3 size of leader required. 75x50 solution 15 square inches and from table vi it is found that a 4 1 2 inch pipe has an area slightly greater than 15 inches. Size horizontal storm drainage piping.

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. 1106 3 vertical leader sizing vertical leaders shall be sized based on the flow rate from horizontal gutters or the maximum flow rate through roof drains. 1 inch 25 4 mm 1 foot 304 8 mm 1 gallon per minute 3 785 l m.

Roof area is 300 x 500 ft. Step by step sizing of zurn drains step 1. Four steps to sizing roof drains.