Plants for an intensive green roof may be able to have a deeper root system.
Extensive green roof construction.
For an extensive green roof the plants should be able to grow in under 5 inches of soil.
8 to 20 per square foot.
Step one primary waterproofing layer.
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.
Green roof irrigation system.
Extensive green roofs which are most often used for residential homes do not require watering.
Intensive roof construction is largely the same but may involve additional elements.
A semi intensive green roof can give rise to a richer ecology with more diverse plant and animal species.
Moisture retained by media that cannot be removed aka wilt point 12 18 typ.
For both of these we need to follow specific green roof construction and maintenance procedures.
Green roofs can help reduce energy costs for a building by acting as another layer of insulation between the inside and outside of the roof.
A properly designed and installed extensive green roof system can cost 108 248 m 2 10 23 sq ft while an intensive green roof costs 355 2 368 m 2 33 220 sq ft however since most of the materials used to build the green roof can be salvaged it is estimated that the cost of replacing a green roof is generally one third of the initial installation costs.
Moisture retained by saturated media after free draining 40 60 typ.
For a conventional roof.
This is most noticeable in intensive green roofs since there is a thicker and more consistent layer of soil which provides a higher insulating value.
A general characterization of the two types of green roofing systems follows.
Green roof components growing media water holding capacity field capacity maximum water capacity astm test.
Therefore it is unlikely that a green roof will lead to issues with insurance.
15 to 50 per square foot.
It also allows for a formal garden to be installed with paths grass lawn and flowers or pot plants.
Generally there are two types of green roof systems.
Extensive green roofs.
The following steps apply to extensive green roof construction.
The government undertook fire tests for green roofs and walls and concluded that the current guidance provided by the green roof code was adequate and extensive green roofs installed following the code would not be deemed a fire risk.
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.
Typically these roofs will have more soil and some small shrubs as well as the low growing wildflowers and sedums found on an extensive roof.
Your roof deck be it concrete or screed will need to be waterproofed.
Some roofs will already have a waterproof layer.
