What are the different types of green roofs?
The least expensive and lightest type of system, it uses < 6 in. of growing media. Sedum (a drought-tolerant plant) is the primary plant used in extensive green roofs because it can grow in just 1 in. of soil and weigh as little as 8 lbs. per square foot. After a temporary irrigation system is installed during plant establishment, extensive green roofs often require no irrigation.
This system blends characteristics of the extensive and intensive green roof categories. Semi-intensive systems are typically between 4-12 in. soil depth, and may contain a variety of vegetation ranging from sedum to grasses and shrubs.
This is the most sophisticated system, as it contains the largest amount of soil depth at 12-36+ in., and provides a wider variety of options for plant selection. The soil depth of an intensive green roof typically ranges from 12-36+". An intensive green roof is the most expensive, but also has the highest capability to mitigate stormwater runoff and insulate a building.
How much does a green roof weigh?
The weight of a green roof depends on the materials used and type of system installed. During the design phase, Recover always works with a structural engineer to determine a roof's structural loading capacity.
On average, an extensive green roof weighs between 10-30 lbs per square foot; a semi-intensive green roof weighs between 30-50 lbs per square foot; and an intensive green roof weighs between 50-300 lbs per square foot.
How much does a green roof cost?
The price of a green roof varies from project to project, depending largely on the following factors: green roof type, quality of the existing rooftop membrane, roof accessibility and fall protection, structural loading capacity, and ease of material conveyance to the roof.
Price ranges for design-build by system typically fall between:
- Extensive: $10-50+ per square foot
- Semi-Intensive: $25-200+ per square foot
- Intensive: $20-200+ per square foot
What services does Recover Green Roofs provide?
Recover is a design/build/maintain firm, meaning we will work with our clients from the design phase through material sourcing, delivery, conveyance, and installation. After construction, we provide maintenance services to projects we've built as well those built by others in need of maintenance or remediation.