Following the successful acceptance and completion of this project, additional testing and research was conducted under the direction of Henry Company in a laboratory to determine what else can be achieved on roof tops in hurricane zones. The results show that various configurations of Henry 790-11 Hot Rubberized Asphalt Waterproofing with Overloads from Green Roof Outfitters and Owens Corning Extruded Polystyrene can withstand Category IV hurricane-force crosswinds without damaging or moving the components and achieving a wind resistance rating from 350 pounds per square foot.
Over a dozen green roof system models have been built to reflect common green roof and congestion scenarios in many wind zones. The test models included different planting conditions, parapet heights and different options for anchoring components.
Although the wind tunnel was cranked to its maximum capacity during Category IV hurricane strength, there was no displacement or damage to any part of the systems – vegetation sealing. Technical assessments based on a variety of laboratory tests independently confirmed six types of overburden roof systems capable of withstanding wind speeds in the hurricane zone at high speed in the following categories:
Comprehensive green roof systems with anchored components and growing media
Paving stones made of concrete, porcelain and wood, anchored with fastening kits and bases
Artificial turf anchored to fixed bases
Green infrastructure with hurricane strength
Wind increase concerns have slowed green roof development in many urban hurricane zones, particularly Florida, the Carolinas, and Texas. It has slowed the development of vegetation on the structure for high-rise buildings and those exposed to sea-effect winds. Green roofs are the solution to so many environmental problems caused by urban development, including rainwater management, heat island effect and air pollution. With this study recently overseen by Henry Company, designers and city planners can now safely incorporate the vegetation on the structure in all wind zones into their green infrastructure strategies.