Roof Drain Pipe Design

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Roof drain pipe design.

To convert to an area for use in table 1108 2 do this. A minimum 5 inch diameter drain on a 1 4 inch per foot slope is required. Use this downspout extension to divert water away from the foundation or connect to drainage pipe and catch basin to control drainage. The published roof drain flow rate based on the head of water above the roof drain shall be used to size the storm drain drainage system in accordance with section 1106.

This reveals that the minimum size for the leader pipe is 5. 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. The result is the number of drains needed. Note that roof drain bodies and vertical conductors are sized utilizing a different table that a horizontally sloped storm line.

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. Section 101 5 of the ipc tells us not to reduce the pipe size in the direction of flow. Section 1105 roof drains 1105 2 roof drain flow rate. The flexible design easily bends and holds its shape and can be extended from 25 in.

Different horizontal sloping will offer different drainage capacities. Hy tech is an authorized distributor of all roof drain manufacturers so you can find what you need when you need it. We also stock many of the top selling drains and parts onsite so most orders ship same day. The calculations below are meant for drainage from flat roofs where water are expected to spread over the entire flat roof during rain.

Or 12 drains required. 1 8 1 4 and 1 2 per foot. Take the roof s total square footage and divide by the total square footage handled by one drain. The flow rate used for sizing the storm drainage piping shall be based on the maximum anticipated ponding on the roof.

But this isn t the whole story. Rd rd 10 000 4 x 3 75 9 375 sq ft. Cast iron roof drain with 2 in. Pipe sizing is listed as amount of square foot roof areas served by the drains.

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. Code tables outline pipe slopes of. Horizontal drain 10 000 sq ft. 50 000 4 400 11 36.

The roof drainage outlets and rainwater downpipes are calculated based on the design principles for gravity drainage systems established in ss525 2006 code of practice for drainage of roofs.