Roof Drain Layout

The sizing of roof drains must be large enough to quickly carry away all water entering the roof drains.

Roof drain layout.

Use at least two drains where possible. General roof drain system guidelines. From the edge of a valley. The full flow capacity of a drain is not realized until the water reaches approximately 2 5 above the inlet in a four inch drain and 3 5 in a six inch drain.

It is very critical to position drains for maximum effect. From a roof edge. Install a drain at most 50 ft. There are three types of drain systems on a flat roof.

The next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout. This form of roof drainage is preferred if a clean exterior appearance is desired. So often we find that inner drains are high on the roof causing water to pool around them. Roof drains zurn plumbing products groupspecification drainage operation 1801 pittsburgh avenue erie pa 16502 phone 814 455 0921 fax.

Limit roof area to 25 000 sq. Most draining systems on flat roofs have a poor design or are not correctly installed. Install a drain at most 50 ft. These will drain to somewhere near the center of the roof and down through the building to underground storm mains or a detention pond.

Following are some basic design guidelines to consider as part of your project courtesy of jay r.