Roof Drain Layout

This form of roof drainage is preferred if a clean exterior appearance is desired.

Roof drain layout.

Factors which affect proper roof drainage are deck slope drain size and placement of drains. From the edge of a valley. General roof drain system guidelines. So often we find that inner drains are high on the roof causing water to pool around them.

The next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout. The roof is sloped towards the drain through either tapered insulation or through joist modifications below the roofline. Roof drains zurn plumbing products groupspecification drainage operation 1801 pittsburgh avenue erie pa 16502 phone 814 455 0921 fax. 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. Use at least two drains where possible. Most draining systems on flat roofs have a poor design or are not correctly installed. Limit roof area to 25 000 sq.

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. 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. Install a drain at most 50 ft.

From a roof edge.