While green roofs terraces can be installed in different types of ceilings, they must meet a number of structural and safety conditions for these ecological systems can be developed without causing inconvenience to the building or its occupants.
In many cities there are legal frameworks governing the requirements to be met by the surfaces on which to install the green terraces (especially if it is the intensive type), and often these requirements are based on a series of conditions set by the International Green Roof Association (IGRA):
Roof substructure: surfaces can be covered with wood, sheet metal or reinforced concrete, provided they have protection against water and able to withstand the weight of all components of the green deck.
Waterproofing layer: It should be resistant to penetration of roots. Under IGRA, there are at least seventy business models that have this particular feature. To avoid problems, you should not only cover layer roof surface, but also ribs, perimeters, joints and edges of the roof.
Edge height: At least 150 millimeters to the side of the adjacent buildings and entrances, and 100 mm for the rest of the edges of the roof itself.
Tilt: The green roofs can be installed not only on conventional flat surfaces, but also for those with an inclination less than 45 degrees.
Carrying Capacity: The structure on which you want to install a green roof terrace or must be able to withstand the load resulting from the sum of the weight of the layers of fertile soil, vegetation grown in the same and the accumulation of irrigation water and rainfall. For example, the thin green roofs extend can weigh 60 to 150 kg/m2, while the intensive type ranging from 180-500 kg/m2 because they require a greater thickness of soil and usually accommodate large plants and building elements such as pergolas and pathways.
Effects of wind resistance: The floor of the green roof must be securely fastened to the surface. The real influence of the wind depends on the height of the building, the type of terrace, slope and area occupied and the substructure on which it is seated.
Storm-water Drainage: The green terraces store most of the annual precipitation and then released into the atmosphere through transpiration. Depending on the thickness of the green deck and accumulation and intensity of rainfall, the excess water may accumulate at certain times and must be evacuated out of the roof area via free drainage outlets in soil or vegetation.
Accessibility: Access to green terraces, both for installation tasks as its maintenance, should be easy and safe.