Green Roof Drainage Plan

Green roof design.

Green roof drainage plan.

Flow of water into them is promoted by positive drainage. The design of the different drainage layers allows for a portion of the stormwater to be retained above where the water is allowed to flow freely off of the roof. For flat or nearly flat roofs primary drains are located at the lowest point of the roof. The systems are designed to ensure that stormwater can be used by plants for longer periods of time without oversaturation of the system.

As a rule of thumb a pitch under 10 degrees is normal for green roofs where a minimum fall of 1 60 can help encourage drainage. Green roofs comprise a multi layered system that covers the roof of a building or podium structure with vegetation cover landscaping. Green roofs have influence on cost reduction due to low or no need for raincatching cisterns and similar equipment which is usually used for. A green roof may need to incorporate edge detailing around mechanical structures and should be.

The roof is likely to consist of an impermeable layer a susbstrate or growing medium and a drainage layer although not all green roofs require a drainage layer. Drainage protection filtration layer it is used for lightweight green roofs terraces and has many functions. The roof can often be the space where major building systems are specified including for mep. The green roof design needs to accommodate adequate water retention suitable drainage structural loading and the depth of green roof growing substrate.

Bauder sdf drainage layer material of the drainage layer polyamide monofilament weight of the drainage layer 400 g m. A major advantage of green roofs is the reduction of storm water runoff which leads to a decrease of the burden on sewer systems by 50 90 in summer depending on the green roof design and local climate. Green roof systems can be modular layered systems already prepared in trays including drainage layers growing media and plants or each component of the system can be installed separately on top of the structure. It is made of a filtration veil and the polyamide monofilament fibre network layer.

A green roof may require a separately plumbed secondary drainage system also known as the overflow relief system.