Fire Concerns Continue to Drive Prescriptive Codes
by Richard K. Olson, president & technical director, Tile Roofing Industry Alliance
(Editor’s Note: Richard K. Olson is president and technical director for the Tile Roofing Industry Alliance. The association represents industry professionals involved in the manufacturing and installation of concrete and clay tile roofs in the United States and Canada, and works with national, state, and local building officials to develop installation techniques, codes, and standards for better roofing systems. Olson can be reached at email@example.com.)
Building performance in fire-prone areas continues to be the topic of discussion for building owners, code officials, and more. The recent decision to create forced power blackouts to reduce potential spark ignition by the power companies is further complicating the evacuation, communication, and response options when fires breakout. The roof systems become one of the critical areas for seeking new and improved field practices to help reduce the spread of fire. Over the last five years, there have been numerous products and practices that can be incorporated into the roof assembly with minimal cost impacts that can be applied to both new and existing roof installations.
Most roof claddings now have the ability to reach a Class A fire-rated assembly through improved underlayments and alternative fire-rated sheathings. Some products, such as concrete and clay tiles, have always carried the Class A ratings as a product and as a system, where others might require additional components to meet the specification.
With the increased fire incidences, the expansion of the Wildfire Urban Interface code designation to more urban and city regions continues. These areas require additional prescriptive products and practices to help reduce fire combustion from occurring. The greatest requirement is the upgrade to a 72 lb. cap sheet that will prevent embers and spread of flame activity. This will require the roofing professional to determine how best to prevent water infiltration, as a 72 lb. cap sheet is not a viable underlayment for most roof systems.
The ability to help reduce openings around roof penetrations is another area where embers can be prevented from entering the assembly. With soil pipes and vents, higher-rated caulkings or sealants can be added to reduce the openings where access under the roof or wall cladding might occur. As part of reroof and roof maintenance, these are areas that should be addressed on a regular schedule.
Skylights and chimneys create areas where transitions of the roof cladding to flashings can leave small gaps that create fire opportunities. For chimneys, or other larger structures that utilize crickets, the ongoing maintenance to reduce debris build up should be incorporated into regular maintenance schedules. When fires occur, the wind acceleration around these structures can increase temperatures and combustion of adjacent materials differently from the field areas of a roof.
Valley areas are another opportunity for upgraded practices, and the choice of open or closed valleys might be considered for the various external factors of the building. The presence of trees, foliage, or other combustible materials can allow accumulations in the valley areas. This not only creates damming opportunities for water flow, but can create fire-prone areas that will combust at relatively low temperatures when embers come in contact.
In areas where gutters are used, the addition of gutter guards and regular cleaning to remove accumulations of combustible materials will need to be utilized to help reduce the fire hazards. The placement of gutter guards may reduce, but not always remove all of the materials that accumulate. For products such as concrete and clay tiles, or other claddings that have additional airflow underneath, the proper use of bird stops and eave closures to reduce large openings will improve the roof performance. The eave overhang is one of the critical areas for ember entrance in building structures.
As part of the regular roof maintenance programs, the identification of landscape challenges might be reviewed. The ability to help create a greater defensible space between the roof and the combustible materials will reduce risk exposures. As landscape matures, there is constant erosion of the defensible space from the original intent.
Roofing professionals can work to better understand the local code requirements for design restrictions, product approvals, and best practices required. The ongoing fire events will continue to evolve the codes to greater restrictions in an effort to help improve building and product performance. Roofing contractors can take an important role in the process by connecting with the local building officials to help educate them on practices the industry has identified. The roofing industry’s collective voice can help improve roof performance.