The planting medium in extensive green roofs ranges from 1 6 to 6 inches deep and while deeper systems have been installed they are not favored as much as the shallower systems drought tolerant sedums succulent plants and grasses are the typical plants used since they are shallow rooted and use little water plant diversity on these roofs is kept low to simplify care and to be sure all plants have similar moisture requirements.
Intensive green roof depth.
Therefore a significant amount of attention should be always paid to the waterproofing issues as well as root barrier details as modern tray systems are not a viable option for this type of roof.
There are two types of green roof.
Intensive green roofs require a depth of soil of about 600mm require irrigation weeding and care.
A typical growing medium depth of an intensive green roof is 6 inches or more.
Depth of growing media between 150 mm and 900 mm.
The extensive green roof the extensive type of green roof by contrast have a soil depth of 50 150mm only support very drought.
This system supports everything from small personal home gardens to full scale public parks.
Intensive green roofs are the traditional garden roofs and can support a varied selection of plants.
The depth of an intensive green roof is tied to the soil depth which is obviously affected by the frequency of mounding that is used.
When used in conjunction with hydrotech s full line of hardscape elements such as architecturally finished pavers and precast items the system is ideal for roofs and plazas that will serve as pedestrian recreational areas.
Intensive green roofs offer a great potential for design and biodiversity.
One important item to design for is an increased structural load.
This is especially true of intensive green roofs which can have soil that is two feet deep or more.
The structural engineer must factor in the weight of completely saturated soil since the plantings and the soil will hold a significant amount of water.
For intensive green roof profiles a drain restrictor may be used to retain water in the base of the profile for subsequent plant transpiration.
An intensive green roof is a deeper typically greater than six inches heavier system designed to sustain complex landscapes.
Plant selection and design greatly affects the maintenance required for the upkeep of these roofs.
Designed or semi intensive vegetative green roofs in terms of requirements fall in between extensive and intensive vegetative green roof systems.
Thus they have more substantial structural loads and need more frequent maintenance and watering.
Features of intensive garden roof assembly.
They are usually accessible.
Intensive roofs which are thicker with a minimum depth of 12 8 cm 5 1 16 in and can support a wider variety of plants but are heavier and require more maintenance and extensive roofs which are shallow ranging in depth from 2 cm 13 16 in to 12 7 cm 5 in lighter than intensive green roofs and require minimal maintenance.