Roof Drain Layout

General roof drain system guidelines.

Roof drain layout.

These will drain to somewhere near the center of the roof and down through the building to underground storm mains or a detention pond. Roof drains zurn plumbing products groupspecification drainage operation 1801 pittsburgh avenue erie pa 16502 phone 814 455 0921 fax. There are three types of drain systems on a flat roof. Install a drain at most 50 ft.

The next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout. Limit roof area to 25 000 sq. Use at least two drains where possible. 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.

This form of roof drainage is preferred if a clean exterior appearance is desired. Following are some basic design guidelines to consider as part of your project courtesy of jay r. From the edge of a valley. So often we find that inner drains are high on the roof causing water to pool around them.

The sizing of roof drains must be large enough to quickly carry away all water entering the roof drains. It is very critical to position drains for maximum effect. The roof is sloped towards the drain through either tapered insulation or through joist modifications below the roofline. From a roof edge.

Most draining systems on flat roofs have a poor design or are not correctly installed.