By Ann Rubin
(KSDK) - Firefighters put their lives on the line day in and day out, but now there's a new hazard that's putting them even more at risk.
It's a type of floor construction that burns and falls apart faster than traditional floors, and it's found in more than half of all new homes. The structural components often burn through so quickly, firefighters can't get out in time and end up falling right through the floor.
That is exactly what happened during a house fire on March 30 in St. Charles. A woman was trapped and there was a problem.
Firefighter Chris Blackwell says just a few feet inside the doorway, the floor was actually gone.
A small section burned, and the rest began to cave. Firefighters carrying the victim actually tumbled eight feet to the basement below. Fortunately other crews were waiting.
"They noticed us coming down and more or less broke our fall -- one of my crew member’s fall and our victim's fall, and they removed her through a basement window,” says Blackwell.
Firefighters falling through floors in happening in newly constructed homes across the country. The problem, they say, is the manufactured floor support, which thanks to technology, is much different than it used to be.
"Our experience is the manufactured flooring systems do prematurely fail even after they've experienced a small volume or small duration of fire,” says Blackwell.
This is becoming a fact of life for firefighters. They say this type of flooring construction is becoming more and more common. In fact it's now found in more than half of all new home construction.
They are constructed using engineered or pre-made components, and often held together with metal plates or adhesive.
One of these floors supported by a wood truss system belongs to Fire Battalion Chief Harry Fry.
"They're easy to put up, they're lighter, they're strong, but they don't hold up in direct flame,” says Fry.
In response to growing concerns, there have been studies done about these floors. One study conducted by the Engineered Wood Association fire-tested pre-made supports called I-joists and compared them to traditional timber supports.
They burned in half the time. Part of the problem with the joists and trusses appears to be that they have more exposed surface area and less wood to burn.
"Once this type of construction is involved in direct flame contact, it's five minutes or less and we could have a serious collapse,” says St. Charles Captain Dan Casey.
The National Wood Flooring Association based in Chesterfield says it's important for homeowners to know how their floors are supported.
"Your trusses, they let them go wider and longer spans without support and then you add a little bit thinner sub floor and thinner floor and someone's going to go through it quicker I would assume,” says instructor Steve Seabaugh.
Still the materials are extremely popular. Builders say they're stable, lightweight and environmentally friendly.
"They're a better performing product, more durable product as far as building a home,” says home builder Matt Belcher.
Belcher is also a former building inspector. He says he understands the firefighters concerns. He hopes local government will try harder to regulate their safety.
"The technology is growing so fast with these better built and more advanced products, the building codes are actually struggling to keep up a little bit,” says Belcher.
For now firefighters are taking safety into their own hands.
"We have to adapt to what's around us," says Casey.
That means keeping rescue teams at the ready and using infrared cameras to look under the floors in new homes.
"That's why we go in with these thermal imagers. If we see that there's some flame involved in the truss construction, we know we've got to get out or get done what we're doing and evacuate,” says Casey.
The victim in the St. Charles fire did not survive. Firefighters can't help but wonder if the outcome would have been different if the floor held up.
Is there a way to make your floor safer? One study found putting a layer of gypsum wallboard underneath the joists seemed to help. That floor held up for nearly 33 minutes in a controlled fire.
But each fire is different and unpredictable. Firefighters say the best thing you can do is have smoke detectors and an exit strategy.