There are two primary categories for Green/Garden roofing:

Extensive Green Roofing

Extensive Green Roofing is usually specified with less than six-inches of growing media and is a light weight application. This makes them acceptable for installation on existing buildings with limited structural capacity. Due to the narrow profile of extensive roofing, a limited selection of plant material can thrive. Typically, vegetation found in deserts and rocky alpine meadows is utilized. Extensive Green Roofing is most always associated with modular planting systems and foliage trays available through many manufacturers. 

Intensive Green Roofing

Intensive Green Roofing is usually over six-inches in depth and can sometimes be as deep as four feet. This deeper profile adds substantial loads to a structure, but allows for a wide variety of planting medium. Due to structural requirements of this application, Intensive Green Roofing is typically associated with new construction. This ensures that the correct design criteria and structural requirements are met, allowing for the additional loads. Intensive roof systems are engineered with a series of roofing components, drainage systems and multiple layers of planting medium assembled on-site. Intensive Green Roofing allows for the most creative designs in Green/Garden roof system.