Green RoofAs energy demands continue to threaten power supplies and smog continues to deteriorate the health and quality of our cities, consumers are learning more about one of the most exciting and innovative roofing systems on the market-- the Green roof. Green roofs have been popular in Europe since the 1970s with over 100 million square feet of planted roofs to-date. However, the complexity and exorbitant price of these European built-in-place systems led US designers to create modular innovations for more cost-efficient, high performance versions. Green roofs are extensions of the existing roof that allow plants, trees, shrubs, and even edible vegetation to grow and thrive in a lightweight growing medium. These generally come in three systems: complete systems where all components, including roof membrane, are an integral part of the entire roofing system; modular systems that are laid on top of the existing roofing system; pre-cultivated vegetation blankets that consist of growing mediums and plants that are rolled over the existing roofing system with draining mats and root barriers. The choice of type depends on the climate, budget, and function of the building, in most cases. When properly designed, Green roofs are stable, living ecosystems that replicate many of the processes found in nature. Green roofing systems deliver a host of benefits and often come with government incentives. Many cities provide tax breaks to companies that employ this roofing system because it prevents storm water runoff, which helps prevent raw sewage from overflowing off the surface and into drains during heavy rains. Green roofs also detract from the urban "heat island" effect, which occurs in most major cities in the world. Urban "heat island" effect has been shown to change weather patterns in major cities. Roads and building rooftops absorb a significant amount of heat during daylight hours. This heat, in turn, is radiated back into the atmosphere, causing further warming. To compound the problem, vehicles and HVAC systems emit additional heat. These factors can result in a 6- to 10-degree temperature increase in large cities. While green roofs help to insulate and shade buildings, they also return moisture to the air, cooling the atmosphere around them in a process called 'evapotranspiration'. In large-scale usage, these factors have the potential to significantly reduce the urban heat island effect and also the pandemic effects of global warming. In addition to the eco-friendly benefits of Green roofs, they also dramatically enhance roof life (more than doubling the service life of the roof), improve building performance by reducing heating and cooling requirements, absorb sound reflection and transmission, promote a healthier environment by creating a wildlife habitat, improve air and water quality, and improve the aesthetic environment. Green roofs create space and improve property and community value as well by eliminating the need to create additional storm run-off structures and reducing pollution as well as improving the appeal of the building and areas surrounding. Some structures even contain fruit groves and edible plants that reduce food expenses and promote a healthier work environment. With these affordable innovations in roofing systems, Green roofs are the premier choice for all-around high performance buildings.
|
