Low Pitch Green Roof

Green roofs lower surface temperatures often by 50 degrees fahrenheit or more.

Low pitch green roof.

Drainage thickness of growing media plant varieties etc. Most vegetation will grow on quite sever slopes but the designer must consider the practicalities of installing the green roof and just as importantly how the roof is to be maintained. The most crucial component of any sloped green roof is the confinement system which holds the growth medium in place during the roof s early stages of development. In retrofit projects a sub framing system is attached to the existing flat roof surface to provide a minimum 12 roof pitch.

Sloped roofs retain less water in general and the moisture content varies from the ridge to the eave lowest edge of the roof. If not properly secured a pitched vegetated roof can erode and slip under heavy rain excessive irrigation or poor plant growth. It is the task of the designer to make adjustments in the green roof system accordingly e g. For a green roof installation that pitch should be at least inch per foot of run.

Before the plants go up a structural engineer should check to ensure that the roof can support the weight of the engineered growing medium and plants. Even a flat roof should have some pitch so that it sheds water toward gutters.