Roof Drain Layout

Install a drain at most 50 ft.

Roof drain layout. 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. These will drain to somewhere near the center of the roof and down through the building to underground storm mains or a detention pond. Factors which affect proper roof drainage are deck slope drain size and placement of drains.

The roof is sloped towards the drain through either tapered insulation or through joist modifications below the roofline. General roof drain system guidelines. From a roof edge. 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.

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. There are three types of drain systems on a flat roof. It is very critical to position drains for maximum effect.

Most draining systems on flat roofs have a poor design or are not correctly installed. So often we find that inner drains are high on the roof causing water to pool around them. Following are some basic design guidelines to consider as part of your project courtesy of jay r. The sizing of roof drains must be large enough to quickly carry away all water entering the roof drains.

From the edge of a valley.