Flat Roof Rainwater Drainage

6 24 2014 david howard aia said.

Flat roof rainwater drainage.

The result is the number of drains needed. Inner roof drains. The roof drainage outlets and rainwater downpipes are calculated based on the design principles for gravity drainage systems established in ss525 2006 code of practice for drainage of roofs. The main benefit of inner drains is that the system is hidden from view.

Increasing the angle of a flat roof will always. Number of roof drains needed on flat roofs. There are several drainage options to repair pooling or ponding water on flat roofs including internal drains gutters and downspouts scuppers and roof leveling compounds. Screw a drain cover over the end of the tubing as it approaches daylight to keep critters out.

They are ideal for climates that don t experience large quantities of rain and moisture. How water runs off a roof depends on the amount of rainfall and how quickly it needs to drain. This table is based on zurn s roof drain vertical requirement for horizontal roof areas at various rainfall rates table. A rooftop garden or additional outside living space are the top reasons people choose flat roofs.

Flat roofing comes with many benefits but it needs to have the correct drainage systems installed to ensure that water is removed effectively and doesn t collect on the surface. Flat roofs have unique architectural characteristics that make them desirable in many situations. 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. Specifying the drainage requirements for flat roofs reader question.

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. Take the roof s total square footage and divide by the total square footage handled by one drain. The greenslope roof ponding repair kit provides a lightweight inexpensive solution to flat roof ponding. Ponding water on flat roofs reduces the roof s lifespan.

The above sizing data is offered as a guide only. In this section we ve included a range of flat roof drainage options parts and accessories to suit your latest professional or diy projects. The calculations below are meant for drainage from flat roofs where water are expected to spread over the entire flat roof during rain. Inner roof drains are used on flat roofs and include a low section or channel that collects water and feeds it into a concealed drain that leads to an underground drainage system.

Gutters are the most commonly used and most cost effective drainage solution for flat roofs. What is the general area of a flat 1 4 1 0 slope single ply roof for each roof drain ratio for the number of roof drains roof area. For a large roof it is recommended to have drains placed at multiple locations within the area of the roof. The 3 most common drain systems of a flat roof.