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 roof system weight.
Smaller thickness of the system will not compromise the performance due to the fact that urbanscape green roll can hold up to 3 4 times more water per its volume than other green roof substrates.
Extensive modular green roofs.
Intensive green roofs.
A shallow layer of growing medium supports low growing stress tolerant plants that can generally look after themselves.
25 40 lbs ft.
35 80 lbs ft.
Mosses sedums succulents herbs and few grasses.
Extensive green roofs are designed to be low maintenance lightweight systems with no general access.
8 to 20 per square foot.
Green roof system weights columbia green technologies 79 se taylor st.
The two key elements that contribute to weight are the density of the different layers that make up the green roof and how heavy it becomes as a result of rain absorption.
Sedum roofs with a natural drainage layer are designed to maximize water retention while sedum roofs with a synthetic drainage layer may focus more on minimizing weight.
Extensive green roofs sedum roof systems.
15 to 50 per square foot.
For a conventional roof.
15 25 lbs ft.
What contributes to green roof weight.
Sedum roofs are extensive green roofs that have a media depth of 3 8 inches.
For example a traditional intensive green roof system for plants and grass featuring at least six layers including soil filter fleece drainage layer and vegetation is.
There are two variations for the system build up.
Extensive systems weigh anywhere from 10 to 25 pounds per square foot when dry which is why the interlocking system of trays is important otherwise strong winds could very easily blow the plantings away.
The biggest benefit of extensive green roofs is that they need very little maintenance.
7 24 inches.
Extensive roofs are typically lightweight and can be installed over a variety of structures including metal roof decks.
An extensive garden roof assembly can be applied to flat roofs and sloping roofs with a pitch of up to 12 12 or 45 provided the appropriate measures are taken to cope with the shear forces and soil retention.
Selected perennials sedums ornamental grasses herbs and little shrubs.
Typically they have thin layers of substrate the growing medium to keep depth and weight to a minimum.
O verall depth 3 5 inches.