Flat Roof Drainage Downspout

Most flat roofs suffer from poor drain locations or drain levels that are high.

Flat roof drainage downspout.

Take the roof s total square footage and divide by the total square footage handled by one drain. This is where the rainwater is lead away from the building s foundation so that no rainwater is able to pool around the building. Of course the best designed flat roof has the correct amount of pitch to drain the water off naturally. When designing a roof it is essential to pay close attention to where the drains are.

In reality a flat roof isn t fully level and flat roofs built for gutters should direct water to one or more sides where the gutters are installed. Smacna s new downspout and gutter sizing calculator enables the user to manually enter the design area of the roof or use the design area wizard for the calculation. On many occasions drains are too high and water cannot flow off. Gutters are the most commonly used and most cost effective drainage solution for flat roofs.

Along with the benefits of a flat roof come unique challenges. See french drains for details of handling roof runoff at flat or poorly drained sites. To prevent erosion make a rock bed around the end of the tube. Gutters are often a viable option for flat roofs directing water on the outside of the structure to downspouts.

The flexible design easily bends and holds its shape and can be extended from 25 in. Having sufficient drainage on a flat roof is vital. Gutters can also be installed to work in tandem with a scupper system. Use this downspout extension to divert water away from the foundation or connect to drainage pipe and catch basin to control drainage.

Where the tube passes by the downspout from the gutter we installed a y fitting and drained the roof water from the gutter system directly into the main drainage line. They catch rainwater as it rolls off the edge of the roof and divert the water into a downspout that dispenses it a safe distance from the foundation of the building. The most critical of these issues is the flat roof drainage systems. This wizard makes it easy to calculate the roof design area by providing various shape calculations and the calculation for vertical walls area per international plumbing code ipc.

Screw a drain cover over the end of the tubing as it approaches daylight to keep critters out. For flat sites it may be necessary to drain into a drywell or french drain system or into a pumping chamber that sends drainage to a remote storm drain or drywell. The result is the number of drains needed. Your building and location can help determine which drain will fit your roof needs.