Roof Rainwater Drainage Systems

As the roof collects rain the water must be transported quickly and safely away by a drainage system.

Roof rainwater drainage systems.

Rain gutters are the most common drain system in use for all types of roofs. 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. Because the siphoning force helps move the water siphonic drain systems can employ horizontal leaders instead of sloped pipes which rely on gravity alone for drainage. See french drains for details of handling roof runoff at flat or poorly drained sites.

Rainwater harvest calculator length. The cistern typically located underground may be constructed of various materials including cinderblock reinforced concrete or precast concrete fiberglass or steel. The 6 slotted triangle shape is used beneath the aggredrain layer and allows for water to flow freely. Commonly used on flat commercial roofs siphonic drains allow for a minimal number of drains and all of the drains can be connected to a single leader.

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. Siphonic drains typically cost more than other drain systems but they work smoothly and require relatively little maintenance. Scuppers are the most effective drainage solution for flat roofs. With this system large square openings are made along the edge of the roof that shoot the water away from the side of the building.

To use this calculator input the dimensions of your roof only area connected to rainwater harvesting system and the amount of rainfall in inches. But don t let it scare you. Commercial flat roofs need interior drains and scuppers to collect water instead. Keeps water from pouring off of the roof in an uncontrollable manner.

Although they do have their benefits they also tend to be favored less due to several reasons. That line eventually emptied into the low spot in the back yard. The 1 100 rain water catchment system. This is a large rainwater catchment system.

The green roof solutions drainage conduit is a stainless steel channel for use with the aggredrain system. High maintenance gutters need continual cleaning and. Protects doorways and window openings. While pitched roofs can rely on gravity to move water flat roofs can t just rely on a typical gravity driven gutter system.

A system of gutters and downspouts directs the rainwater collected by the roof to the storage cistern.