Division of green roofs due to the intensity of greening:
• Ekstensywne – Low plants with low vegetation requirements, which can independently support and develop like steppe vegetation. They need occasional care and don't need to be watered. Zaletą dachu ekstensywnego jest niewielka grubość i stosunkowo niski ciężar warstwy wegetacyjnej i roślin, which is from 20 do 30 kg/m2. Extensive green roofs can be made on a roofing with an inclination angle of up to approx. 30%.
• Intensywne – Intensive greening can be created by various plant species – from mosses and sedum plants to certain species of trees and shrubs. Intensely green roofs have a thick layer of vegetation and heavy weight (do 500 kg/m2). Roofs with intensive greening require systematic care as well as regular irrigation and supply of nutrients, therefore, irrigation systems are often installed on it, used during drought.
Green roofs are most often designed in the inverted flat roof technology. Two layers of bituminous felt waterproofing are placed below the thermal insulation made of extruded polystyrene boards, on a lightweight concrete slope. Inverted layer arrangement protects waterproofing from damage by penetration of plant roots and gardening, ensuring long-term tightness of the waterproofing. Above the thermal insulation there is a gravel filtering layer protected on both sides with fleece, and only above it a vegetative layer of humus.
Green roofs usually have internal drainage.It is recommended to use roof outlets with chambers brought to the surface, which allows you to collect rainwater from the upper layer with vegetation.