Dense urban areas are especially vulnerable to the impact of rising temperatures due to the heat island effect. The Department of Energy (DOE) recognizes the employment of cool roofing strategies to combat urban heat islands and reduce the use of air-conditioning systems.
In the last two decades, the improved technologies of silicone, acrylic, and polyurethane have become better integrated into basic roofing practice, not only expanding the range of roofing applications but also competing successfully against the traditional asphalt coatings used for maintaining traditional built-up (BUR) roofs. Today, most manufacturers of entire roof assemblies also have a coatings line, including at least two of these four technologies.
North America’s first product category rule (PCR) for roof coatings has been created by NSF International and the Roof Coatings Manufacturers Association (RCMA). This PCR, which covers fluid-applied and adherent coatings used either for roof maintenance/repair or as part of a roof covering system or assembly, offers the industry a number of benefits.
Selecting the proper reroofing material for a given structure after an existing assembly has reached the end of its useful life can be a daunting decision. Affordability, among other technical and performance considerations, remains at the top of the list of most building owners’ concerns.
When replacing a roof, it has generally been good practice to tear off the existing assembly and replace it with new material. However, this is beginning to change. Simply getting rid of an older roof may not be the best choice for the building owner or the environment.