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.
Consider engineered lumber, a structural member made of wood fibers and materials bonded with adhesive or other methods, which 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 of how 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 lightweight construction. The UL report “Structural Stability of Engineered Lumber in Fire Conditions” indicated that the unprotected lightweight construction assembly collapsed in six minutes versus the nearly 19 minutes it took for the unprotected “legacy" materials to collapse. Adding a half-inch-thick generic gypsum board covering to the legacy materials lengthened its time to collapse to 44 minutes; the same protection applied to the lightweight assembly improved its time to collapse to 27 minutes.
The National Research Council Canada (NRC) also examined how fire impacts unprotected floor assemblies. In its research, NRC concluded that lightweight assemblies reached structural failure 35 to 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.
Construction materials aren’t the only things in homes that are burning quicker than their older counterparts. Modern furnishings in many households are constructed with synthetic materials—upholstery made with combustible polyurethane foam, for example—that burns 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.
A proven method for reducing fire’s impact at home 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 required sprinkler installation in new, one- and two-family homes. Mounting research confirms that sprinklers save property, protect lives, and benefit the environment.
This article originally appeared in a special edition of NFPA Journal, the magazine for the National Fire Protection Association, dedicated to home fire sprinklers. For additional articles from that issue, read the online edition. For questions regarding fire sprinkler installation, contact the National Fire Protection Association at FireSprinklerInitiative@NFPA.org.