Roof Drainage Pipe Design

The maximum rainfall rate anticipated in the area where the building is located the flow in liters per minute per square meter for some x number of minutes.

Roof drainage pipe design.

Does not include branches of the building drain refer to table 710 1 1. Buried or underground roof drainage downspout defects clogging overflowing holes corrosion leaks that cause wet basements or crawl areas proper installation of buried downspout extensions proper installation of french drains seepage pits at flat sites gutter downspout defects cause wet basements crawl areas questions answers about installing maintaining repairing buried roof. Use this downspout extension to divert water away from the foundation or connect to drainage pipe and catch basin to control drainage. Different horizontal sloping will offer different drainage capacities.

Featuring durable vinyl construction this extension can be buried bent or connected to additional sections. To size the vertical roof drain for the same parameters 5 000 square feet of room area and 6 per hour of rain consult table 1106 2 figure 3. Note that roof drain bodies and vertical conductors are sized utilizing a different table that a horizontally sloped storm line. Crickets are additional layers of ta.

A siphonic roof drain has a special insert that acts as an air baffle and anti vortex vane such that only water is drawn off of the roof not air. Stacks shall be sized based on the total accumulated connected load at each story or branch interval as the total accumulated connected load decreases stacks are permitted to be reduced in size. Unlike traditional roof drainage systems a siphonic system is designed to operate with the piping completely charged with water during a rainstorm. In general roof drains are spaced equally and are located in low points of the roof or in any areas where water accumulates.

The intersection of the panels creates mitered valleys that direct wa ter into the roof drain. 1 inch 25 4 mm. Code tables outline pipe slopes of. To design a sloped or flat roof drainage system we need to know several things.

50 000 4 400 11 36. The flexible design easily bends and holds its shape and can be extended from 25 in. According to the chart for 1 8 slope per 12 of pipe for 5 000 square feet of roof area with a 6 per hour of rainfall the required pipe size is 8. Take the roof s total square footage and divide by the total square footage handled by one drain.

Ing square roof drain catchment areas with tapered insulation panels sloped equally in four different directions with the high point at the perimeter of the roof and the low point at the roof drain. Each leader must be large enough to handle the volume of water to be drained the greater the leader capacity the fewer roof drains are needed. The result is the number of drains needed. Stack diameters shall not be reduced to less than one half of the diameter of the largest stack size.

But this isn t the whole story. Or 12 drains required. Pipe sizing is listed as amount of square foot roof areas served by the drains.