Staying Safe
Designing Steep-Slope Roofing for Enhanced Fire Resilience
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 rolson@tileroofing.org.)
As wildfires continue to devastate communities across the country, fire resilience in building design has never been more critical. In fire-prone regions, incorporating fire-resistant materials, creating defensible spaces, and ensuring proper fire-rated assemblies are essential strategies to mitigate risk and improve safety. With insurers increasingly assessing wildfire risk, there is growing pressure on lawmakers and code developers to adopt stricter performance standards. The insurance industry is poised to play a pivotal role, not only in shaping regulations but also in driving the demand for innovative fire safety products and practices. As these trends unfold, building designs that integrate advanced fire mitigation techniques may soon become industry standard, with insurers offering incentives for higher safety measures to reduce claims and liabilities.
Roofs, as one of the most exposed components of a structure, play a vital role in preventing fire spread. Steep-slope roofing, commonly found in residential and some commercial buildings, requires specific design strategies to enhance fire resistance. While minimizing the number of roof planes can reduce vulnerability, incorporating design aids can allow for complex geometries while still maintaining fire resilience. As design professionals we need to explore the best practices for designing fire-resilient steep-slope roofs, including material selection, structural considerations, and maintenance strategies.
Industry trade associations play a crucial role in advancing fire-resistant roofing solutions. Organizations such as the Tile Roofing Industry Alliance, Metal Roofing Alliance, and Asphalt Roofing Manufacturers Association provide extensive research, testing data, and best practices for improving fire resilience. These groups collaborate with fire safety experts, code officials, and manufacturers to develop standards and guidelines that enhance roofing performance in wildfire-prone areas. Leveraging their expertise and resources can help architects, builders, and homeowners make informed decisions about materials and design strategies that optimize fire protection.
Steep-slope roofs have distinct advantages in fire-prone environments due to their ability to shed debris and embers more effectively than low-slope roofs. However, design flaws such as complex roof geometries, combustible materials, and inadequate ventilation systems can increase fire risk. Key threats for the design professional to consider include: windborne embers, flame exposure, and radiant heat.
When evaluating your design for fire resiliency, it is essential to distinguish between product and assembly fire ratings. Concrete and clay roof tiles inherently achieve a Class A fire rating both as individual products and as part of an assembly. In contrast, other roofing materials may require additional components within a system to achieve a Class A rating. Understanding this distinction ensures that your roofing design meets the highest fire resistance standards for enhanced safety and durability.
As design professionals we need to allow for complex roof geometries that the consumer demands to have greater architectural appeal and modern designs while still building in enhanced fire resistance. While simplified roof designs minimize ember intrusion points, complex roof geometries can still be fire-resilient when designed appropriately. Selecting higher fire-rated materials is essential for reducing the risk of ignition and flame spread. By code, roofing materials are classified based on fire resistance ratings for both a product and then an assembly.
When evaluating your design for fire resiliency, it is essential to distinguish between product and assembly fire ratings. Concrete and clay roof tiles inherently achieve a Class A fire rating both as individual products and as part of an assembly. In contrast, other roofing materials may require additional components within a system to achieve a Class A rating. Understanding this distinction ensures that your roofing design meets the highest fire resistance standards for enhanced safety and durability.
Other considerations are to enhance fire resistance through underlayment and decking materials. As with cladding selection, review of the material ratings and restrictions should be performed. It is important to use code-evaluated materials that meet the fire ratings for which you are designing. Underlayment and decking play a crucial role in preventing fire from penetrating the roof system.
Designing steep-slope roofing for fire resilience involves a combination of strategic architectural planning, material selection, and regular maintenance. By incorporating design aids such as fire-resistant valleys, ridges, and intersections, complex roof geometries can still achieve high fire resilience. Selecting fire-resistant materials and implementing ember-resistant features further enhances protection. A proactive approach to fire-safe roofing not only enhances safety but also increases the longevity and durability of the structure. As wildfires and fire-related risks continue to rise, integrating these best practices into steep-slope roof design is essential for protecting lives and property.
