8 to 20 per square foot.
Extensive green roof vs internsive.
An extensive green roof is characterized by a thinner layer of soil and smaller plants.
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.
Extensive green roof an extensive green roof system is characterized of its vegetation ranging from sedums to small grasses herbs and flowering herbaceous plants which need little maintenance and no permanent irrigation system the growing medium depth for an extensive green roof system is typically 6 inches or less.
Unlike intensive garden roof assemblies extensive garden roofs are not intended for recreational use and are typically chosen for their appearance or to help reduce the urban heat island.
Semi intensive green roofs require a deeper soil layer but the payoff is in the types of plantings that can be used.
A 2006 study by the university of michigan comparing costs of conventional and green roofs showed that on average installing a green roof costs about 22 00 sq.
Extensive green roofs.
Semi intensive green roofs as their name states are a combination of the aforementioned two types.
15 to 50 per square foot.
Semi intensive roofs are generally used within highly visible area s to improve aesthetic design using small shrubs forbs and grasses.
These systems are ideal for efficient stormwater.
In addition to the mosses grasses and sedum of extensive roofs semi intensive plantings include herbs flowering plants taller grasses and small shrubs.
The extensive garden roof assembly is ideally suited for locations that will receive little maintenance or where structural capabilities are a concern.
Intensive vs extensive a green roof comes in two varieties.
A semi intensive green roof can give rise to a richer ecology with more diverse plant and animal species.
Extensive roofs are thin lightweight roof systems that typically have a planting media measuring 6 to 20 cm deep while heavier thicker green roofs are known as intensive roofs and their growing media ranges in thickness from 20 cm to 100 cm.
For a conventional roof.
Intensive includes a thick layer of soil that can support large vegetation such as small trees.
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.
A green roof has many advantages.
A green roof is a flat roof that may be systematically planted with for example varieties of sedum moss or grass but also with perennials and even bushes and trees.
It also allows for a formal garden to be installed with paths grass lawn and flowers or pot plants.
To bear this weight an expensive custom support structure is required.