Why modern homes burn faster


The Laconia Daily Sun

Published: 01-28-2022 3:22 PM

As the winter season rolls around, readers might have noticed an increase in reports of house fires, usually resulting in the complete destruction of the structure. This is due to the time of year, and the fact that modern buildings are more flammable than in the past.

“December has been a very busy month for our office,” state Fire Investigator Matthew Wilmot said toward the end of 2021, following a fire in Tuftonboro that destroyed a single family home. “Generally we typically experience more fires in the winter that relate to home heating, whether it’s people using wood stoves, appliances, supplemental heater, disposing of ashes in an unsafe manner, things of that nature.”

According to a study conducted by the U.S. Fire Service, in the wintertime, structure fires increase, while total fire incidents decrease. The data states that in an average year, heating is the cause of 17% of structure fires. This number increases to 27% during the winter months.

On top of the increased fire risk that comes with the cold season, local fire chiefs were quick to point out that modern homes burn faster than their predecessors due lighter weight and cheaper materials.

“That seems to be the way of today’s buildings, they go so quickly,” said Tuftonboro Fire Chief Adam Thompson, citing recent fires in the Lakes Region, “especially with the vinyl siding. An older home, as far as the ones built 100 years ago, did not burn as quickly as today’s day and age. All the new materials do not last as long and they’re a lot more flammable than in the older days.”

One aspect that makes newer materials more flammable is their width.

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“Back in the day we would build a roof structure with two-inch by eight-inch rafters. It holds snow and so on,” said Wolfeboro Fire Chief Tom Zotti. “Contrast that with a new building where you might be using two-by-three trusses. Imagine how much less time it takes to burn through a three-inch-wide truss and an eight-inch-wide truss.”

Wilmot elaborated further on the structural issues with modern, cheaper materials found in today’s buildings.

“It has to do with the mass of some of these construction components, they are lighter, have larger surface areas, which means the effects of heat and fire can break them down more quickly,” Wilmot explained. “The actual composition of the materials, some of them are compressed wood fibers that are glued together. Under normal conditions they can carry the weight they are rated for. But once exposed to heat and fire, that type of material will often fail more quickly. The glue that holds the fibers together can fail more quickly.”

In addition to materials like glue, which can drastically change their structure when exposed to extreme heat, others are inherently flammable.

“Look at what’s in it,” Zotti said. “Eighty-five percent of what’s in it is made out of petroleum products. It burns. Vinyl siding. It’s flammable,” Zotti continued, citing that many of the items in the average home are also highly prone to combustion.

“Your furniture. Back in the day it was all wood and wonderfully made,” Zotti said. “Now, we buy a desk at Target and assemble it and it’s basically cardboard. The fire load in buildings is dramatically higher than back in the day, so things tend to happen very quickly. That’s why we encourage smoke detection if you don’t have it. Carbon monoxide detection if you don’t have it. Because you’re trying to get people out of the building.”

All of this fuel, composed of furniture, synthetic fabrics, paper waste, plastics and other materials that make up a majority of modern possessions, allows rooms to more quickly reach a flashover point — when everything in a given room reaches its ignition temperature and burns at the same time.

Due to these factors, modern firefighters have to focus more and more on speed.

“Don’t get me wrong, this is the world we work in as a fire service,” Zotti said. “The current building construction and so forth is perfectly legitimate and approved, but as a fire service we have to be conscious of that and adjust our tactics accordingly because this happens a lot faster than it used to.”

As for prevention, both fire chiefs and the investigator stressed the use of up-to-date smoke and carbon monoxide detectors, to have as early a warning as possible. Experts also say to keep snow cleared from fire hydrants, keep vents uncovered, avoiding using ovens to heat homes, and to exercise extra caution when operating devices like space heaters.

These articles are being shared by partners in The Granite State News Collaborative. For more information visit collaborativenh.org.]]>