Roof Rainwater Drainage System

Ensuring drainage with a flat roof.

Roof rainwater drainage system.

As the roof collects rain the water must be transported quickly and safely away by a drainage system. Screw a drain cover over the end of the tubing as it approaches daylight to keep critters out. It is important for architects plumbing engineers and civil engineers to work together to design a system that will properly drain rainwater from a building and site. Use this downspout extension to divert water away from the foundation or connect to drainage pipe and catch basin to control drainage.

Blockages in the under floor drain combined with high volumes of roof runoff water entering the system send the entire roof runoff into the building basement or crawl space debris flowing down the downspout drain leaves from gutters can block floor drains or even the main building sewer line leading to sewage backups into the structure. Buildup of rainwater on a roof can cause structural damage and leaks. Your building and location can help determine which drain will fit your roof needs. The key to keeping buildings dry under a flat roof is to be sure that rainwater and other precipitation drains freely and completely off the roof.

Along with the benefits of a flat roof come unique challenges. The best type for the application depends on several factors such as the size and slope of the roof the desired appearance and how much regular maintenance the drain system might need. Of course the best designed flat roof has the correct amount of pitch to drain the water off naturally. Improper gutter drainage can cause erosion of soils and foundation issues.

The most critical of these issues is the flat roof drainage systems. The flexible design easily bends and holds its shape and can be extended from 25 in. Unlike other roofing types that are slanted or sloped to allow water to drain automatically flat roofs need a built in drainage system to help remove moisture and debris. Since flat roofs do not have the pitched sections of a traditional roof it is harder to guide the water off the roof.

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. While pitched roofs can rely on gravity to move water flat roofs can t just rely on a typical gravity driven gutter system. The one challenge with flat roofing is ensuring proper drainage. To prevent erosion make a rock bed around the end of the tube.