Green roofs - good idea as they provide good microclimate in the house. In the Scandinavian countries, for example, for a long time know about advantages of gardening of roof – in the summer they give pleasant cool, in the winter - keep heat.
1. Before beginning to plant trees and shrubs in roof, it is necessary to find out design features of the last. It is necessary to consider that it is additional loading for design. Here the professional advice of the architect or construction engineer will be necessary. In case of new building, loading pays off at design. If you want to plant trees and shrubs in already existing building, it is necessary to check what additional loading the roof will be able to accept. Depending on gardening density, on rafter design the weight from 25 to 165 kg is the share of square meter.
2. Extensive and intensive gardening of kryshiob of option differ on density. Extensive gardening turns out, first of all, from xerophilous plants, for example, from moss. Advantages: gardening of roof does not demand leaving and has the insignificant weight which will be suitable for thin roof, as at garage. Certainly, extensive gardening of roof gives smaller isolation. Intensive gardening is full-fledged construction. Here grassy perennials as asters, daisies can grow, poured, various herbs and even trees. Shortcoming: such gardening will be appropriate only on the strong designs maintaining heavy load.
3. Device of green roof: functional the sloizeleny roof consists of several functional layers. Base layer which is placed directly on roof - waterproofing. Its function is in taking away excess water, and to prevent dampness of the soil for future plants. Further there is protective layer from roots. The following layer - drainage which function consists in absorption and removal of excessive moisture. Then - the filtrational layer separating drainage from soil. In order that has not washed away soil rains and under gravitation force it was not deformed, stack geogrid. That substrate did not slip, you can strengthen on roof thresholds from sliding. Thus everything will remain on the place. Further there is layer of earth. At the same time the earth should be covered with thin layer of mulch which will give nutrients and to support growth of plants. The finishing layer - vegetable.