Green roofs have traditionally been categorised as extensive or intensive.
Intensive green roof definition.
This deeper soil allows intensive roofs to accommodate large plants and dramatic plant groupings.
From a distance an extensive sedum roof can be mistaken for a grass field.
Intensive green roof plants require the deepest soil but also have the greatest impact on structural design.
Intensive green roofs have more soil and a deeper growing medium sometimes several feet that can support a more diverse plant selection including small trees.
They are usually accessible.
These are covered with low growing plants such as evergreen sedums.
Considered by many to be the green oasis in a modern cityscape intensive green roof systems come with a whole new technology based on environmental consciousness directly improving the air pollution heat and many other issues.
Intensive systems allow the designer to create a park like setting so they are the best option for roof gardens that will be occupied.
They generally have lower water requirements and use small low growing plant species particularly succulents.
To start with take a look at the most simple family of green roofs.
Extensive green roofs are lightweight with a shallow layer of growing substrate of less than 200 mm deep requiring minimal maintenance.
Intensive green roof garden roof roof garden an intensive green roof system is characterized by its variety of vegetation ranging from herbaceous plants to small trees with professionel maintenance and advanced green roof irrigation systems.
Another term for these green roofs is rooftop garden.
Besides the visual impact of an extensive green roof they also provide a natural habitat for birds and insects.
The intensive green roof uses planting mediums that have greater depth than the extensive green roof.
A typical growing medium depth of an intensive green roof is 6 inches or more.
The depth of an intensive green roof ranges from 15 cm to as much as 150 cm and can easily weigh as much 300 to more than 1500 kg m2.
Intensive green roofs offer a great potential for design and biodiversity.
You can compare an intensive roof to a normal garden and this is why an intensive green roof is also known as a roof garden or garden roof.
The growing medium depth for an extensive green roof system is typically 6 inches or less.
Intensive green roofs require the deepest soil and have the greatest impact on the structural design but they also accommodate all types of plantings including large shrubs and trees.
Thus they have more substantial structural loads and need more frequent maintenance and watering.