The Roofing System That is Built to Resist Heat

By Robin Anderson, Westlake Royal Roofing Solutions. 

Learn how Unified Steel Stone Coated Roofing is proven to provide ignition resistance to homes. 

Over the past few years, wildfires have become more devastatingly destructive. Because of this, homeowners and roofing industry professionals have been seeking more ignition-resistant construction materials. The roof is considered essential when addressing fire safety concerns as it is more likely for house fires to start on the roof due to flying embers from wildfires. 

Key fire statistics 

Climate change indicators data from the U.S. Environmental Protection Agency provides key insights into fire risk: 

• Since 1983, the National Interagency Fire Center documented an average of approximately 70,000 wildfires per year. 
• The extent of area burned by wildfires annually appears to have increased since the 1980s. 
• Fire damage varies by state; however, fires burn more land in the Western United States than in the East. 
• Burned acreage in the West has increased noticeably in nearly every month of the year when comparing the period from 2002 to 2020 to the prior period (1984 to 2001). 

Embers, wind and Class A roofs 

As a fire burns, embers are emitted and are pushed by the winds generated by the fire. The type of fire determines the amount of embers produced, as well as the distance those embers travel. Embers can carry enough heat energy to ignite combustible structures and ignition can occur when they blow against, or land upon, the surfaces of a home. Science supporting the critical need for ignition-resistant construction specifically features Class A roofing (among screened attic vents and composite decking) as a significant defense against ember-initiated ignition of homes and structures. 

Class A rated roofs encompass the covering material and the overall assembly and are tested by a third-party lab which subjects the roofing assembly to a fire brand test, ASTM E-108 Burning Brand, among other tests. To be deemed Class A, the fire cannot penetrate the roof or cause the structure to ignite before the brand is consumed and burns out during the test period. 

The benefits of Unified Steel Stone Coated Roofing 

Unified Steel™ Stone Coated Roofing materials can resist very high temperatures and are proven to provide ignition resistance. A lightweight roofing material, at 1.5 pounds per square foot, stone-coated steel benefits from the structural strength of steel and is used in both new construction and in roofing retrofits. The high-quality steel is treated with primers to enhance the adhesion of the acrylic polymer base coat that is used to bond stone granules to the steel. The resulting roof system helps withstand the test of time no matter the climate or condition.  

For product warranty details, please see Unified Steel™ Product Warranty. The warranty found there is the sole warranty applicable to Unified Steel™ Stone Coated Roofing products. 

Building codes and assembly considerations 

State-by-state building codes address Class A roofing. For example, current building code in California, a state known for severe wildfire risk, mandates the roof assembly is installed in accordance with its listing and the manufacturer’s installation instructions to be ignition resistant. For Unified Steel™, this requires the roof assembly include a specific underlayment such as Sol-R-Skin™ BLUE. 

Westlake Royal Roofing Solutions’ guidelines approve Unified Steel™ panels to be installed either on a batten or direct-to-deck (the latter is commonly used when the existing sub-deck is solid or spaced sheathed, eliminating the batten needing to act as the panel support). Today’s panel designs also allow for exposed or hidden fastening systems.  

Roof gutters are also addressed in California’s code. The code states they must be provided with the means to prevent accumulation of leaves and debris. Stone coated steel roofs can use gutter guards in a fine mesh to allow water into the gutter but prevent leaves and debris from entering.  

California’s building code also advises on roof coverings, stating where the roof profile allows a space between the roof covering and roof decking, the spaces shall be constructed to prevent the intrusion of flames and embers, be fire-stopped with approved materials like Sol-R-Skin BLUE, or have one layer of minimum 72-pound mineral surfaced non-perforated cap sheet complying with ASTM D3909 installed over the combustible decking. 

California code also includes roof valley treatments. When installed per Unified Steel’s guidelines, utilizing proper underlayment and the 26-gauge corrosion-resistant steel valley metal, the system can meet the requirements set by the state.    

“The importance of an ignition-resistant roof material and assembly cannot be overstated, especially in fire-prone regions” says Mark McMillan, sales manager with Horn Brothers Roofing, a Colorado-based roofing contractor. “Stone coated steel roofing has been growing in popularity amongst our customers because of its ability to protect homes from ignition caused by flying embers.” 

Original article source: Westlake Royal Roofing Solutions