Roof Drain Layout

Install a drain at most 50 ft.

Roof drain layout.

Use at least two drains where possible. General roof drain system guidelines. The roof is sloped towards the drain through either tapered insulation or through joist modifications below the roofline. So often we find that inner drains are high on the roof causing water to pool around them.

From the edge of a valley. The next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout. 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.

Install a drain at most 50 ft. 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. The sizing of roof drains must be large enough to quickly carry away all water entering the roof drains. Limit roof area to 25 000 sq.

There are three types of drain systems on a flat roof. Following are some basic design guidelines to consider as part of your project courtesy of jay r. Roof drains zurn plumbing products groupspecification drainage operation 1801 pittsburgh avenue erie pa 16502 phone 814 455 0921 fax. These will drain to somewhere near the center of the roof and down through the building to underground storm mains or a detention pond.

From a roof edge.