ELKO — With the growth of lightweight construction, fire departments are seeing differences in fire behavior and they are stepping up their planning and education.
“We’re dealing with a completely different fire environment,” said Fire Capt. James Johnston II during a presentation to the City Council last week.
What this means for firefighters is they need to cut response times and change tactics. The average “escape” time in lightweight construction is about four minutes. In older construction it was about 20 minutes, Johnston said.
City of Elko Fire Chief Matt Griego said the difference in burn times has to do with how the buildings are constructed and the materials used in modern construction. Because commercial buildings have sprinkler or alarm systems, the lightweight construction buildings that require more prevention and early detection are residential homes.
“It’s not that (lightweight construction is) junk, it’s very effective for our day and age,” said Fire Marshal Josh Carson. “It just poses new challenges.”
Lightweight construction began to appear 25 years ago and is widely used by residential builders to cut costs. It burns quicker and fails faster than older construction, and can collapse without warning.
Still, there are fewer structure fires today than in the past, Griego said. The Elko Fire Department reported 26 structure fires in 2014, only 1.13 percent of its total calls. Structure fires, including fire in mobile property used as a fixed structure, accounted for 50 percent of all fires in Elko.
“Today we have all kinds of safety features on our appliances,” said Tanamera Construction Superintendent Mike Grant.
Electrical and gas systems are also inspected to prevent a fire from starting, and LED lighting in multifamily housing produces less heat.
“Everything is more thought out, more proficiently done these days,” Grant said.
Griego said fire codes in residential structures are adequate because most of the time it is not the house itself causing the fire but something that’s been introduced.
In commercial structures, alarms give the fire department immediate notice of the fire, so quick action can be taken. Sprinklers can also stop the spread of fire, allowing for more escape time. Homes, however, don’t often have these features, so it’s important for firefighters to assess a situation and know how the fire behaves.
From floor to roof
When fire makes contact with the structural components of lightweight flooring, the floor will collapse in four minutes or less.
Johnston explained that the floor joists used today are thinner than materials used in older flooring. When the glue in these components heats, they begin to fall apart. Older flooring has full dimension, thick beams that burn less rapidly.
The roofs in lightweight construction also become quickly unstable in a fire.
“There’s no positive connection between the wood trusses,” Johnston said.
Instead of being connected inside with nails like in older houses, metal fasteners called gusset plates hold members of the truss together on the outside. Charred wood will cause these to come apart, and the truss to fail.
“If one of those trusses fails, then the whole roof assembly fails,” Griego said.
Furthermore, the glue that holds the manufactured beams together will melt with exposure to heat, he said.
More than 60 percent of roof structures in the U.S. are constructed with lightweight wood truss construction techniques, Johnston said.
On average, it takes the Elko Fire Department nearly eight minutes to respond to a fire call, according to its incident summary report for the year-to-date. When firefighters arrive on scene, they assess time, value and size to determine their strategy and risk in entering a building.
“They’ve got to really watch how long that structure’s been burning, and realize that the failure rate could be much quicker,” Griego said.
A firefighter also considers whether there is someone savable inside the building, and how large the fire is. Griego said there have been no injuries to fire personnel in Elko related to floor or roof collapse.
Besides the construction materials themselves, there are other factors that cause modern homes to burn faster than those made before 1980. These include the introduction of more synthetic materials — in appliances, floors, furnishings, finishes, etc.
“The fires are getting hotter than they used to be and more toxic,” Johnston said.
Nylon, plastic and synthetic materials produce hydrogen cyanide, carbon monoxide, carbon dioxide and phosgene gases that are very flammable.
“Smoke is fuel, especially in modern furnishings,” Johnston said.
Griego said another contributor to the spreading of fire is the open-concept idea in modern construction. While a wall or closed door can slow a fire, giving more time for escape, larger homes and ones with wide-open spaces are at risk.
Drywall will deter a fire’s path, but many unfinished basements have exposed beams.
Lightweight construction is here to stay, Griego said, and for firefighters, it’s just a matter of being aware that it is different than older construction. Its benefits are that it has structural integrity, costs less and is faster to build.
The National Fire Protection Association said lightweight construction has consistently demonstrated equal or superior quality under non-fire conditions. It’s been used in up to two-third of all one- and two- bedroom homes built since the mid 1990s.
Education and prevention
Having a functional smoke detector and a fire escape plan is one way a homeowner can potentially save structures and lives.
“You have less than four minutes to evacuate your home,” Griego said. “You need that early detection from that smoke detector and a plan to get out.”
Griego said homes account for about 20 percent of fires, but 80 percent of deaths.
Home monitoring systems are also showing success in early detection.
“We’ve had several fires where we had the notification that saved the home,” Griego said.
For the year-to-date, Elko has had $193,703 in property loss to burned structures, out of a potential $4 million.
Sprinkler systems can be installed in homes, but add a much higher cost to the home construction. Still, Griego said these were recently installed in some townhomes on Khoury Lane that had access difficulties. A full story on those systems will appear in a future Free Press.
The City fire department is working to cut down response times.
“With the shorter burn times, we need to be able to get there quicker either to save the structure or save lives,” Griego said.
The department can speed up turnout time with training and station design.
“We can shave seconds there, but where we can shave minutes is with station locations,” he said.
Griego said the Elko Fire Department has 18 career firefighters in one manned station and 21 volunteer firefighters in two volunteer stations.
The city’s main fire station was placed closer to the airport because about four hours a day, someone is needed to be available for the Elko Regional Airport due to Federal Aviation Administration regulations.
“Most of the new modern lightweight construction is north of the freeway,” Griego said.
This creates longer response times to some of those homes.
Each shift has six people, or a minimum of five, on staff at the main station. They are the first responders, while volunteer crews may arrive on the scene of a larger fire later.
Griego said he believes the City has sufficient fire stations, but he wanted City Council to have the information it needs to potentially move the station in the future.