It’s Not Your Grandfather’s Fire
Lightweight construction has fire prevention implications, too
By Jim Crawford

“It’s not your grandfather’s fire.”

That phrase was used by Bob Backstrom of Underwriters Laboratories (UL) to describe the kind of fire produced by modern contents, construction techniques and materials. I rarely run across such a succinct way of describing an issue. The key is understanding how it will impact our operations in the future.

By now, many in the fire service have heard of the dangers to firefighters from engineered wood products used in modern construction. Lightweight, less expensive and structurally sound construction materials that are “engineered” (meaning designed structural elements, not dimensional lumber) are receiving strong support and use in the construction industry. And for good reason: They’re less expensive and work well—in normal conditions.

But recent field experiences and some studies have also pointed out that such materials fail more quickly in a fire than the old-style wood-frame construction. That creates a hazard for firefighters, who risk falling through a roof or even a floor made with lightweight construction more quickly than they anticipate.

The Proof
Recently, UL conducted a large-scale test in its labs on some more modern construction materials and the older-style (called legacy) construction to see how fires would evolve. Done under a research grant from the Assistance to Firefighters Grant (AFG) program, this study produced some remarkable comparisons about how fires behave under the different construction types.

UL constructed two different houses in their laboratories, set them on fire, then observed and recorded the results of the fire evolution rates and various ventilation techniques. They presented the results at a seminar during Fire-Rescue International, and the video showed quite clearly that older contents and construction practices produced a much longer fire evolution timeframe than that of modern contents and construction techniques.

When I was “growing up” as a young firefighter, we were often warned about older construction practices, including balloon construction that did not use fire stops. Such features contributed to rapid fire spread. But older homes that included fire stopping burned in a fashion for which we were collectively trained—ventilate as quickly as possible to more easily discover the seat of the fire and extinguish it in the most efficient manner possible.

What Does This Mean for Prevention?
I’ll leave it to the operational (suppression) experts to describe the firefighting techniques that will change due to modern construction practices. But prevention practitioners face some obvious lessons as well.

A faster-moving fire translates into three things when considering the prevention perspective:

1.First, the argument that modern homes are less likely to have fires has less meaning than it once may have had. Traditionally, newer homes were more expensive (unless they’re in a gentrified area where older homes are remodeled and upscale), meaning that those who lived in them were more affluent.

Those of us in prevention know that more fires occur in lower-income neighborhoods, where housing stock is generally older. But the more affluent among us are living in homes that are newer, and would subsequently be exposed to more rapidly spreading fires when they do occur. That’s an oversimplification of course, but I say it to make a point. (Note: There’s also some anecdotal evidence that modern homes have an equal number of fires, but that’s a topic for more study unless there’s one out there I haven’t seen.)

On the other hand, modern construction practices relative to electrical safety have in fact removed some of the hazards associated with older homes, so the idea that modern construction may be less likely to have fires could have some validity. Again—a call for more study.

2. However, the number of fires occurring is only one factor, and especially so if the fires that do occur burn more quickly. So the second issue is that fires that burn more quickly support the need for greater fire protection in modern construction. That would include early detection of fires for evacuation (i.e., smoke alarms) and early suppression from residential fire sprinkler systems.

I’m not naïve to the arguments used by the homebuilders that fire sprinklers add costs to construction. They do, albeit arguably less than some say. But as an efficient method to provide fire protection over the long term, sprinklers are unmatched. We may be looking at a decades-long movement that begins to transition the way we provide primary fire protection for our housing and building stock. And there will be a lot of prevention and firefighting between now and then.

3. So the third point I’d like to make is that funding was available in this case for real-world research that provides us with data to help point us in a productive direction. Instead of relying on a well-intentioned retired fire marshal’s opinion, we begin to have a more reasoned and enlightened way of making decisions in code promulgation and prevention practices. Far more research of this type is needed in the area of prevention strategies.

Old or New
In reality, in old construction or new, we can and still should make the case for prevention strategies that reduce the incidence of fire before it occurs. And that too is another topic worthy of discussion.

For those with an interest in this particular topic—and more research that is available from UL—you can learn much more by going to their website. And if you want to talk with the man who coined the phrase, you can also contact Mr. Backstrom directly at Robert.G.Backstrom@us.ul.com.

I encourage readers to get this information, and use it locally to support their prevention efforts.

Jim Crawford recently retired as deputy chief and fire marshal with the Vancouver (Wash.) Fire Department and is chair of the NFPA technical committee on professional qualifications for fire marshals. He has written “Fire Prevention: A Comprehensive Approach,” published by Brady, and has also written a chapter on fire prevention in “Managing Fire and Rescue Services,” published by the International City/County Managers Association. Crawford is a past president of the International Fire Marshals Association and has served on the NFPA’s Standards Council. He is a member of the IAFC.

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