|Mature Green Roof at American University|
The first order of business with retrofitting a green roof to an existing roof is a general inspection of the existing conditions. An engineered structural analysis needs to be performed to ensure the roof can handle the extra weight load, and a design for the roofing system needs to be decided on. Thankfully these tasks were already done by the time we arrived on site to begin the work.
Before placing the "green" on the roof, the existing ballast (large gravel) needs to be removed and stored for later use. A root barrier then needs to be installed on all sections of the roof that will receive plantings. After this, a track will be placed to keep the plantings firmly in the desired section of roof. Finally, custom plastic trays will be placed inside the track to provide growing medium for the plants. These plastic trays are a relatively new technology, and allow for easy installation and maintenance on the roof. After all the trays are placed, a gravel track will be placed around the edge of the roof to provide access, as well as easy discovery of roof leakage around the perimeter (which is where most roof leaks occur). Once the trays are installed, they will be connected to an irrigation system and plantings will be placed in the desired locations to finish off the green roof.
|Site Safety Meeting|
|Green Roofing Supplies|
|Removing Ballast with Vacuum|
|Inspecting Existing Conditions|
|Installing Root Barrier|
|Installing Track and Tray System on the Roof|