In many instances an extensive green roof can be a planning requisite and the ideal solution is the simplest lightweight sedum blanket system.
Simple intensive green roof.
They require a layer of growing medium soil to support this much thicker vegetation layer.
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.
Intensive systems allow the designer to create a park like setting so they are the best option for roof gardens that will be occupied.
From a distance an extensive sedum roof can be mistaken for a grass field.
To start with take a look at the most simple family of green roofs.
There are three basic types of green roof system.
You may find that they are referred to as roof gardens.
The basic anatomy of a green roof consists of vegetation growing medium filter membrane drainage layer waterproof root repellant layer roofing membrane support for plantings above thermal insulation vapor control layer and structural roof support.
Is less accessible intended for aesthetic purposes sill allows choice of vegetation requires less maintenance less structural demands is more economical compared to an intensive green roof.
This system is able to retain more stormwater than an extensive system and provides the potential to host a richer ecology.
Extensive systems are for roof areas that are out of reach and not used for other purposes.
These are covered with low growing plants such as evergreen sedums.
Semi intensive green roof a semi intensive green roof system is characterized by small herbaceous plants ground covers grasses and small shrubs requiring moderate maintenance and occasional irrigation.
8 to 20 per square foot.
These areas need appropriate vegetation that will make them low maintenance and self sustaining.
Semi intensive system requires some maintenance from time to time.
With this type of roof planting mediums are much deeper which can be between seven and 24 inches and can consist of lawn shrubs trees and perennials for example.
For a conventional roof.
1 intensive green roof if you want your roof to function as a garden and have large plants and even water features then the intensive green roof is for you.
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.
Intensive green roofs are designed to support much larger items like bushes and small trees as well as a wider variety of plants.
15 to 50 per square foot.
Besides the visual impact of an extensive green roof they also provide a natural habitat for birds and insects.