Roof Drain Leader Pipe

Roof drain selection.

Roof drain leader pipe.

The flow rate in storm drain piping shall not exceed that specified in table 1106 2. Reference leader size with hourly rainfall rate to determine roof area drained by each leader chart b. Downspouts are drainage pipes that direct rain water from the roof to the ground. Sizing a roof water drain 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.

Approximate leader drain pipe size. This flexible downspout extension easily bends and holds its shape and can be extended from 25 55 in. The next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout. Divide roof area 1 by area per leader 4 to determine the number of drains required.

Table 1106 2 storm drain pipe sizing for si. Use this downspout extension to divert water away from the foundation or connect to drainage pipe and catch basin to control drainage. In general increasing leader size will decrease the number of drains required. 1 inch 25 4 mm 1 foot 304 8 mm 1 gallon per minute 3 785 l m.

There is generally a bend of 70 degrees at the bottom. Downspouts are usually vertical and usually extend down to ground level. Featuring durable plastic construction this extension can be buried bent or connected to additional sections.