Green roofs, which are increasingly popular, are typically engineered to be either extensive or intensive.- Extensive
- Relatively light (15-50 pounds/ square inch)
- Relatively shallow growing medium
- Intensive
- Heavy (80-150 pounds/square inch)
- 12” + growing medium
- Regardless of type, properly designed and maintained green roofs can deliver these ecological benefits:
- Conserve energy by moderating roof temperature
- Dramatically reduce storm runoff volume and peak flow rate
- Restore urban ecologies and aesthetics
- Reduce the urban heat island effect
- Protect conventional roofing systems, potentially doubling the life of waterproofing membranes
Irrigation is typically needed during the grow-in phase of green roof vegetation. Supplemental irrigation is usually necessary during the hottest part of the summer. Irrigation systems must be carefully designed, installed and maintained on green roofs, as excessive watering can trigger serious damage.
