Rollovers, Flashovers, and Backdrafts
Rollovers, flashovers, and backdrafts. These three terms are used to describe special fire circumstances. You do not want to be caught in a situation when any of these are happening in your vicinity. Even with all of their equipment, these circumstances are also dangerous for firefighters. What do each of them mean? Why should you be concerned about flashovers? What happens when there is a backdraft? These are terms everyone should be familiar with, as they heavily relate to fire safety. Check out the following video to see these three situations as they develop in a simulator:
Rollover- A rollover is the circumstance in a structure fire when incompletely burned fuels or ignited fire gases spread out horizontally after rising to the ceiling. After this, the smoke suddenly appears to start burning. This special circumstance can lead to a flashover. Check out the following video to see a rollover in action:
Flashover- A flashover is the circumstance in a structure fire when everything in the room suddenly and simultaneously ignites. In full protective gear, a firefighter is even unlikely to survive this event, though they are trained to recognize when a flashover is about to occur. It happens due to several factors. A rollover occurs, with hot gases rising to the ceiling and spreading out across to the walls. The heat intensifies to the point where every combustible item reaches ignition temperatures. This causes them to burst into flames. In a few seconds, temperatures shoot up to as much as 1,000 degrees Fahrenheit or 538 degrees Celsius. Some of the signs of an impending flashover are; “black fire,” which is dense black smoke with tightly packed curls, black smoke which pushes out of a window opening or doorway, and smoke which has gone as low as a doorknob. Check out the following video to see a flashover in action:
Backdraft- A backdraft is when there’s an explosion due to oxygen being let into a room full of hot gases. When a fire is burning in an enclosed area, eventually, it burns up all of the oxygen (it’s oxidizer). This causes hot, flammable gases to fill the room. This leads to temperatures rising and pressure building, causing the building to appear like it’s pulsing or throbbing. If all of a sudden, a door is opened to let in a burst of new oxygen, all of the flammable gases burst into flames, due to the fire being oxidized again, i.e. hot, flammable gases plus fire equals one big explosion. This results in a rolling fireball that no one would ever want to get caught in. Check out the following video to see a backdraft in action:
These three circumstances are incredibly dangerous to get caught in, and you are unlikely to survive. Make fire safety one of your top priorities and make sure you own every kind of fire safety equipment. A smoke detector to warn you of the fire, a fire extinguisher to fight the fire, and a SkySaver when you run out of options and must flee the fire.
Barak Bacharach, SkySaver Content Manager