Green roofs: what and why
The aim of a roof is to protect the building from the effect of the weather, especially the humidity.
An ordinary roof fulfils those requirements perfectly. But other ways are also possible, for example by choosing a ‘green roof’.
A green roof looks attractive. This visual aspect has a positive effect on the mood and physical health of people.
On a green roof, the coverage mainly consists of living plants. In fact, the name “green roof” is a little misleading, after all, this kind of roof does not really have to be green. And nor do the plants growing on it. For example, in the United Kingdom one talks of ‘brown roofs’.
Naturally, plants solely as a roof covering are not sufficient. The basis used for the plants is crucially important. A correct basis with a suitable structure, a suitable substrate and the correct draining facilities are needed.
In fact, a green roof could also be realised in an entirely natural way. The only problem is that nature takes its time about it. In practice, it will easily takes ten- to –twenty years before you get the right effect. If you would like to help nature along, choose the landscaped variety of green roofs.
Intensive greening: creates a roof garden which is comparable to a garden at ground level, both in use and in the required maintenance;
extensive greening: the green roof is low-maintenance but access is limited or even ruled out
In between these two categories, there is also semi-intensive greening.
One cannot say that all green roofs are roof gardens. The opposite does hold true: all roof gardens are green roofs. A “roof garden” is a green roof which has the characteristics of a garden, but which is situated on a roof.
Why opt for a green roof?
a green roof is so much prettier than a conventional roof;
environmentally-friendly: green roofs reduce the pressure on the sewage system, they reduce the risk of flooding, they have a cooling effect, etc.;
economical: investing in a green roof will help you save money. Not only will the waterproofing system on your roof last twice as long, you will also benefit from government grants.