> Energy efficiency. Many PVC vinyl roofing membranes have been recognized by the ENERGY STAR Roof Products Program of the U.S. EPA and the U.S. DOE for their energy savings performance. Some manufacturers offer roofs reflecting in excess of 80% of solar heat. Benefits of using these products include extended roof life, reduced air-conditioning demand and lower surrounding air temperature (reduced “heat island effect”). Asphalt built-up roofs, by comparison, reflect between 6 percent and 26 percent solar heat. All ENERGY STAR-qualifying vinyl roofing systems have been tested as having an initial solar reflectivity of at least 0.65 – meaning that 65% of the solar heat is reflected, and only 35% absorbed (and after three years, a solar reflectivity of 0.50 or greater). In a 2001 federal study, the Lawrence Berkeley National Laboratory (LBNL) measured and calculated the reduction in peak energy demand associated with a PVC roof’s surface reflectivity. LBNL found that, compared to the original black rubber roofing membrane on the Texas retail building studied, a retrofitted PVC vinyl roofing membrane delivered an average decrease of 42º F in surface temperature, an 11% decrease in aggregate air-conditioning energy consumption, and a corresponding 14 percent drop in peak air-conditioning energy consumption.¹
> Resource conservation. Lightweight PVC vinyl roof systems help reduce the dependence on steel and wood that are needed to support heavier roof system options. Vinyl roofing eliminates the need for asphalt, tar and other materials used in built-up roofing and is easily maintained without additional resource expenditures. They are also UV-protected, highly moisture resistant and require no maintenance for decades.
> Outdoor air quality. The light color of PVC vinyl roofing membranes has also been shown to have a positive impact on air quality. Reinforced thermoplastic vinyl roofing membrane has been recognized for its ability to optimize solar-reflective properties, scoring over 104 on the Solar Reflective Index (SRI). This is particularly significant because the SRI was designed to measure the relative reflective and thermal emissive performance properties of roofing surfaces on a scale of 1-100. In addition, NASA researchers found that summertime urban air temperatures can be greatly reduced by using such light roof surfaces as compared to dark-colored industrial/commercial roofing materials. Decreases in urban air temperature can substantially improve air quality, since smog is the result of photochemical reactions that are triggered by air temperature increases. PVC vinyl roofing membranes – when installed on multiple buildings in an urban setting – can diffuse heat within a city and assist in lowering air-conditioning consumption, thereby helping to lessen smog formation.
The process of removal or replacement of existing vinyl roofing membranes releases little or no airborne contaminants. In addition, during installation of vinyl roofing systems, fumes and odor levels are much lower compared with hot kettles, open flame and asphalt or coal tar used to create built-up roofs. And, because vinyl membranes can be hot-air-welded together, there is less need for high-solvent adhesives to close the seams.
> Planted roofs. PVC vinyl roofing membranes can be installed over existing roofs and serve as a vital component in planted roof systems. Employing multi-layer soil and drainage systems, vegetation can grow on urban roofs resulting in energy efficiency of buildings, beautiful green urban rooftops and cleaner air.
¹ S. Konopacki and H. Akbari, “Measured Energy Savings and Demand Reduction from a Reflective Roof Membrane on a Large Retail Store in Austin,” Lawrence Berkeley National Laboratory, Environmental Energy Technologies Division, June 2001.