After the publication of the article, “A Collaborative Approach to Selecting a Roofing System” by Mark Gregory, CGC, CCC, in the January 2018 issue of The Construction Specifier, we received a letter from one of our readers.
The author has not highlighted the important role roofing material manufacturers play in designing a system that protects occupants of a building from the outside environment. Manufacturers along with architects, specifiers, and roofing contractors, play a critical role by working with building owners to ensure they get the right roofing system to suit their needs, design, specification, code requirements, and budget.
As part of this collaboration, manufacturers provide documentation on the fire classification and wind performance of the roofing system being installed.
The article states, “modified-bitumen can also pose a fire hazard if installed on top of a wooden surface.” This statement is misleading, as safeguards must be adhered to for all types of roofing systems––metal, single-ply, coatings, or asphaltic––whether installed on a combustible wood structure or a noncombustible one. Safeguards include proper grounding of equipment as well as generators, seamers, welders, compressors, and spray equipment. Considerations must also be made for the type of products being applied and stored on the roof, including adhesives, primers, and cleaning and insulation materials.
The International Building Code (IBC) requires a fire classification for every installed roofing system, and Class A systems are commonly specified. Modified-bitumen (mod-bit) and built-up roofing (BUR) systems are tested to the same fire standards as others—ASTM E 108, Standard Test Methods for Fire Tests of Roof Coverings or Underwriters Laboratories (UL) 790, Standard Test Methods for Fire Tests of Roof Coverings. Numerous options over combustible decks for mod-bit and BUR systems with Class A, B, and C classifications can be found in Underwriters Laboratories Online Certifications Directory. A number of the components comprising a mod-bit or BUR system incorporate fire-resistant ply and base sheets, reinforced with glass mats.
The Asphalt Roofing Manufacturers Association (ARMA), the trade association representing North America’s asphalt roofing manufacturing companies and their raw material suppliers, offers numerous publications on modified-bitumen and BUR systems, including the Modified Bitumen Design Guide for Building Owners.
Additionally, it is essential the installer follows the quality control criteria set by the roofing manufacturer and printed in its installation instructions. IBC Chapter 15 requires this in numerous sections.
More importantly, quality control is also required in the building codes. Product listings maintained by UL and other certification bodies are required to demonstrate code compliance and include periodic follow-up inspections.
The author is correct regarding the importance of collaborative relationships in the design and installation of roofing systems. This collaboration must include roofing manufacturers, whose expertise is essential when selecting the appropriate roofing system for any commercial structure.
Tim McQuillen, director of technical services, ARMA.
For clarification, we reached out to the article’s author. Mark Gregory offers this response:
Thank you for reading my article! I would like to address your concerns with some of the statements you brought up in the Letter to the Editor. My intent with the article was to demonstrate the importance of a collaborative approach to roofing. The manufacturer can absolutely be a positive part of this collaborative approach. Roofing contractors and installers should have a continuous collaboration with the manufacturers to fully understand the product’s characteristics, warranties, and installation methods.
We were limited on space and we simply could not include every component to the collaborative approach, but the point is to have collaboration between all the parties, including (but not limited to) customer, roofer, local officials (for local codes), manufacturers, power companies (for rebates and such), and engineers. Some of these parties were also not addressed in this particular article as we are directly communicating to architects and specifiers.