There are two types of green roof.
Shallow green roof.
As a roof type that requires frequent maintenance intensive systems can be thought of as gardens on a roof in contrast with an extensive green roof there are almost unlimited possibilities.
Intensive roofs which are thicker with a minimum depth of 12 8 cm 5 1 16 in and can support a wider variety of plants but are heavier and require more maintenance and extensive roofs which are shallow ranging in depth from 2 cm 13 16 in to 12 7 cm 5 in lighter than intensive green roofs and require minimal maintenance.