This story originally appeared in a December 2014 supplement to Builder Magazine.
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When compared to their older counterparts, today’s popular homebuilding materials offer a more economical and environmentally-friendly way of crafting new dwellings. A potentially lesser-known fact is the dramatic way these products respond to fire.
Take, for instance, engineered lumber, a structural member made of wood fibers and materials bonded with adhesive or other methods that is used as a composite joist or beam. Engineered lumber is a member of the "lightweight construction" family of products, which have been thoroughly examined in recent years to address the question: How do homes using this increasingly popular building material react to fire?
In 2008, Underwriters Laboratories (UL) conducted a study comparing traditional wood materials found in older homes with unprotected, lightweight construction. The UL report, "Structural Stability of Engineered Lumber in Fire Conditions," indicated that that the unprotected, lightweight construction assembly collapsed in six minutes versus the 18-and-a-half minutes it took for the "legacy materials" to collapse.
The National Research Council Canada (NRC) also examined how fire impacts unprotected floor assemblies. In its research, NRC concluded that unprotected, lightweight assemblies reached structural failure 35-60 percent faster than solid wood assemblies. A 2012 report from the Fire Protection Research Foundation also underscored the danger of unprotected, engineered lumber during a fire, labeling its rapid structural failure under fire conditions a "high" level of concern.
"Like most things in the modern era, construction materials are becoming more streamlined, efficient, and lightweight," says NFPA's Robert Solomon. "The unintended consequence is that these new techniques and materials bring new fire safety challenges."
Construction materials aren’t the only things in homes that are burning quicker than their older counterparts. Modern furnishings in many households are made with synthetic materials—upholstery stuffed with combustible polyurethane foam, for example—that burn quicker than "legacy" furnishings made of leather, wool, and cotton. UL studies have confirmed that rooms filled with synthetic furniture that are set on fire reach dangerous temperatures quicker than similar rooms filled with legacy furnishings.
In 2013, NFPA reported that fires involving these items accounted for the largest share of fire deaths of any first item ignited in U.S. homes.
"Among the concepts to draw on to make sure that ‘efficient’ can ultimately be equated with ‘safe’ are developing robust test procedures to determine the susceptibility that upholstered furniture has to a flaming ignition source, continuing to understand the behavior of engineered lumber in unpredictable fire scenarios, and making sure that first responders are trained to identify the reaction of buildings to these relatively new hazards," says Mr. Solomon.
A proven method for reducing fire’s impact at home, says Mr. Solomon, is home fire sprinklers. In 2012, NRC issued another report, "Fire Performance of Protected Floor/Ceiling Assemblies and Impact on Tenability," which evaluated how home fire sprinklers impact fire spread. In all tests, sprinklers kept conditions tenable and helped prevent the structural failure and collapse witnessed during its previous study.
Since home fire sprinklers can douse a fire or control it until the fire department arrives, all U.S. model building codes have made sprinkler installation a requirement in new, one- and two-family homes. Mounting research confirms that sprinklers save property, protect lives, and benefit the environment.
"Fire sprinklers are doable in one- and two-family dwellings," says Tim Travers, one of NFPA’s regional sprinkler specialists. "They do not delay construction, they are not high cost, they can be done easily and simply, and they save lives."
View a presentation on the fire dangers of unprotected, lightweight construction and modern furnishings.
Free copies of the reports mentioned in this story are available on the research page.