There are no maintenance requirements for green roofing.
Extensive green roofs require some maintenance especially in the first year until the plants have established strong root systems and self-sufficiency. Monitoring moisture in the soil and growing material you have laid down for them is important for helping such a root system grow strong, and minimal weeding (though it is present) will be necessary to keep your plants healthy. After the first year there is still some maintenance to be done in your extensive roofing, including making sure your plants are well-irrigated during rainless periods or unusual rain patterns. Once the plants have provided ground cover weeding will be obsolete, but removing debris and leaves that have blown in will be necessary, as well as clipping off dead growth to make room for new life and general cleanup. Fertilization of the soil and materials will become necessary as well after several years to maintain the nutrients and vitamins in the soil that the plants need for survival. If you are unlucky enough to have plants die on you, they will need to be replaced to fill in the gaps and keep the roof uniform.
If you have ever raised and grown your own garden, chances are you have dealt with the type of maintenance needed for an intensive green roof. Depending on the types and varieties of plants you choose to use in your deeper roof, regular clipping or pruning may be necessary aside from the usual plant food and water. Weeds and pesky bugs can find a roof garden just like one down below, so there will be that to take care of as well.
As far as the structure of green roofing goes, the membranes of the roof itself and other key parts of the structure can (as with regular roofs) become aged and damaged with time and the weight load, and may require replacing.
It is impossible to use solar panels for electric generation with a living roof.
In reality, the pairing is acceptable and productive to combine eco-roofs and solar panels. There are usually great temperature changes associated with solar panels, and the plants of a green roof can/will reduce these changes so that they don’t harm the environment. When the heat is higher than usual, the roofing can make the photovoltaics work better, though it is necessary for the panels to be placed above the tallest plants and the plants have to be for extensive green roofing rather than the varieties made for intensive ones.
Leaking is not necessarily one of the things to worry about when dealing with green roofs, or at least no more so than any roof. The key is making sure it is well constructed so that it has the maximum protection. The membrane of a green roof is waterproof and the plants themselves are known to protect the membrane from ultraviolet sunlight and environmental damage.
There is no need to water green roofs.
Watering green roofs is a complicated issue. Intensive green roofing is the type for which it is very necessary to have an irrigation system set up for times of dry or drought-like weather, even though plants you have placed may be drought resistant. The first year of a green roof is another instance in which watering is very important, while the plants establish themselves. Architects and designers almost always plan for an irrigation system of some kind as they build a green roof.
Green roofing is too heavy for the majority of buildings.
Though it is always a good thing to have your roof examined and evaluated for its individual specifications, the truth is that many houses and buildings are designed with the existing weight of the roof and the possibility for ice, snow, water, and wind to add many more pounds in each square foot over time (sometimes over 40 pounds more). If the structure is already built efficiently, it can be quite affordable to do the small necessary reinforcements to handle the 20/30 pounds more of load capacity required for extensive green roofing projects (intensive roofing requires much more load capacity).
They don’t need insulation beneath them in the building.
There is not a lot of research and study results to really have a firm grip on an answer for this one as such insulation requirements are still under study. However, it is thought that there are alternative benefits related to climate control other than insulation benefits. The plants’ ability to reflect heat and their transpiration properties are what are generally credited with keeping a structure cooler in the hotter times. The material in which the plants are placed stays at a constant frozen temperature at the surface of the roof, enabling the inner of the building to fight against only that temperature (no colder) during the winter, reducing heating costs.