Green Roof Installation

Last week Breakell's Patterson Avenue office building began an exciting new phase in it's conversion to a green building. Half of the existing roof was converted to a vegetated roofing system to demonstrate its viability to potential clients. Green roofing technology, while still in its infancy in the United States, has several proven benefits including increased life-span, lower operating costs and improved sound insulation qualities. According to Green Roofs for Healthy Cities, a green roof installation on a typical 1 story office building can achieve 25% reduction in summer cooling loads. The soil and vegetation also retain and filter rainwater, slowing its dispersion to overburdened sewage systems and creating opportunities to capture and reuse this water. All of these features of green roofs help contribute to LEED certification.





At the Breakell office the process took 3 days, with several distinct work items to be done. Phase one involved prepping the roof system to recieve the new system. Several steel trusses were added to beef up the existing roof support due to the added weight of the dirt necessary for this type of system. Once proper reinforcement was put in place, the existing EPDM roof was stripped down to its expanded polystyrene insulation and temporary waterproofing was put in place. Contractors returned on day two to install the waterproofing membrane, root barrier and drainage system to make ready for the dirt and vegetation installation. The third and final day of construction involved the placement of approximately 4 inches of specially engineered roofing soil, topped with various native and drought resistant plant species. This completed the green roofing installation, although the final product will not be fully integrated for up to 6 months.



Continual monitoring of energy consumption through integrated energy monitoring software will allow the results of the green roof installation to be documented and conclusions to be drawn. Through this process, it is Breakell's hope that their office building can serve as an example for other projects as well as a source of experience in this area.



Sources:
Green Roofs for Healthy Cities: www.greenroofs.org
Pictures courtesy of Breakell Incorporated