How fast can an unwatered Christmas tree go up in flames?

Are you watering your Christmas tree enough? If not, it could pose a huge fire risk. Students and faculty at the University of Maryland demonstrated on Tuesday just how fast an unwatered tree can go up in flames.

The UMD Fire Protection Engineering’s Annual Christmas Tree Fire Safety Demonstration showed the difference between how a well-watered tree and a dry tree react to fire.

The dry tree fully engulfed in around 10 seconds, with every branch covered in flames.



“The pine needles are really good at catching on fire,” said Liora Mervis, a senior at UMD studying fire dynamics. “They’re small; they’re dry, and they don’t take as much convection and things like that to start.”

Meanwhile the well-watered tree took 10 times longer to become a full fire and didn’t even fully burn, leaving many branches unscathed.

“It’s about the moisture content of the trees. So water is a really good way of suppressing fires,” Mervis said.

Water absorbs heat very well and without that heat there is no fire.

“A fire tetrahedron, all the components of a fire, that’s how a fire is sustained,” said Mervis. “So you have the heat, the fuel, oxygen, and then you also have the sustaining of the chemical reaction. So when you have water, it kind of takes out that heat.”

Beyond keeping your natural tree well watered, check on Christmas lights for faulty wiring — that is the most common way for a tree to catch fire.

Statistics show tree fires are rare, but when they do happen they are about four times deadlier than other fires.

Data from the National Fire Protection Association show around 160 house fires each year stem from Christmas trees.

Luke Lukert

Since joining WTOP Luke Lukert has held just about every job in the newsroom from producer to web writer and now he works as a full-time reporter. He is an avid fan of UGA football. Go Dawgs!

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