Environmental Services has released a new specification for the design, construction, and operations and maintenance of a simple ecoroof. The specification was created for project managers within the City of Portland to have a quick and easy option for a self-sustaining, low-maintenance and low-cost ecoroof.
The design utilizes a minimalist approach, consisting of soil and sedum cuttings over a waterproof membrane. A red cinder mulch is lightweight and, along with the remaining seedheads, helps to retain moisture and cooler temperatures within the soil. The design has been implemented on both flat and pitched roofs, over EPDM, PVC and modified bitumen roofing membranes, and can boast surviving summer 2012, Portland’s dryest summer on record, without irrigation.
Screenhouse Ecoroof, Columbia Wastewater Treatment Plant
Sellwood Pump Station Ecoroof
Marine Drive Pump Station Ecoroof
There are hundreds of ecoroofs in the City of Portland, most of which are on privately-owned buildings. Thanks to the City's Green Building Policy, new or re-roofed city-owned buildings are required to include an ecoroof whenever practical. Environmental Services has taken the opportunities to innovate new ecoroof designs that cost less, weigh less, and manage stormwater effectively. These innovations can eventually create more opportunities to use ecoroofs city-wide to reduce stormwater runoff from rooftops.
More information about the Portland Ecoroof Program can be found here.