Beaufort, NC, September 29, 2011 – Designing and installing a green roof is a challenging process that considers all the factors that can impact performance, including even a hurricane strike. But only the actual event can truly test the design, and the green roof on the Ocean Conservation Center (OCC) at Duke University’s Marine Laboratory, designed and installed by Living Roofs, Inc., weathered the challenge when Hurricane Irene scored a direct hit on August 27 while at Category 1 status. The roof received eight inches of rain, and was lashed with 80+ mile per hour sustained winds and gusts topping 100 miles per hour.
“The roof did fine in the hurricane,” says Donald Lane of Duke University Marine Laboratory, who noted the roof revealed no signs of soil loss, vegetation damage or overall changes to the system. This was the second major test for the system, with Hurricane Earl passing over in 2010.
Basically, green roofs are roof covers for buildings with growing media and plants taking the place of bare membrane, gravel ballast, shingles or tiles. The number of layers and the layer placement vary from system to system, but all types include a waterproofing layer, drainage, growing media and plants. Green roofs offer a number of energy-saving, cost-reduction and environmental benefits.
The laboratory’s green roof was designed to minimize the effects of uplift pressures during horizontal wind loads. A system by Xero Flor America certified to resist uplift was chosen, but additional measures were utilized to counter the type of effects produced by extremely high winds such as those from a hurricane. These measures include UV-resistant netting held in place by an interlocked perimeter paver system. The two-foot square perimeter pavers are interlocked by stainless steel edging to act as a continuous perimeter weight, pinning down the netting which covers the vegetated area. The netting extends across the green roof from one side to the other, and is tucked under the paver perimeter.
This design was a collaborative effort by the architect (Frank Harmon Architect, PA), green roof system manufacturer (Xero Flor America), roofing contractor (Curtis Construction Company) and Living Roofs, Inc., a leading green roof design and installation company based in Asheville, NC.
Duke OCC Building
Interlocked perimeter paver system
“The roof functioned as anticipated, even under extreme duress, and we’re very pleased with the results,” says Emilio Ancaya, co-founder of Living Roofs, Inc. “We’ll continue to monitor and report performance during future storms since this experience provides additional data we can utilize in improving design and installation techniques.”
About Living Roofs, Inc. Living Roofs, Inc. specializes solely in the design and installation of green roofs and walls. Based in Asheville, North Carolina, the firm teams with landscape architects, architects, contractors and engineers to provide quality green roof designs and systems for both new construction and retrofitted commercial, residential and institutional structures. The Living Roofs, Inc. team also provides consultation services, feasibility studies and cost analyses related to a variety of green roof systems, as well as maintenance services. For additional information, contact Emilio Ancaya at 828/252-4449 or firstname.lastname@example.org, or go to www.livingroofsinc.com.
This video shows the installation process of the green roof on the Repass Ocean Conservation Center at the Duke Marine Lab in Beaufort.