A green roof can increase the life expectancy of a roofing system by protecting the roofing materials from direct ultra violet radiation and extreme temperatures.
Green roof lifespan.
By protecting the roof membrane however a green roof can extend the life of a roof by two or three times beyond its typical lifespan.
Irrigation wastes water and energy both are what the green roof should be conserving.
30 to 50 years is not an unusual lifespan for green roofs in europe.
Green roofing can extend the lifespan of a roof by over 200 by covering the waterproofing membrane with growing medium and vegetation this shields the membrane from ultra violet radiation and physical damage.
In europe where they have been building with green roofs since the 1960s green roofs have been known to last for from 30 to 50 years.