SB Mulch and mulch flammabilityPhoto credit Nicholas Keefer & WMBF.
About 10 days ago, in March 2013, the Carolina Forest community of Windsor Green experienced a devastating fire. Many people associate wildfires happening out west where weather conditions are mostly dry -- not right here in South Carolina near the ocean. National Geographic states, though, that only 3 factors need to be present for a wildfire to occur; this is known as the "fire triangle." The 3 factors are: fuel, oxygen, and a heat source. That being said, Horry County, South Carolina is just as vulnerable to a wild fire as anywhere else in the world.
If a destructive fire is burning out of control, and your home is near it, you are probably going to 

experience a loss. But local disasters like the Windsor Green fire in Carolina Forest present us with a chance to take notice of our surroundings and think about preventative measures we can take if we are ever, God forbid, put in a situation of a wildfire near our home.

What part does landscaping play in the instance of a fire possibly starting at your home? Have you ever considered the flammability of the material in your flower beds? Is mulch flammable?

There are many types of "mulch." Mulch can be wood mulch, pine straw mulch, hardscape mulch such as decorative rock, or rubber mulch. Hardscape mulch is usually not flammable at all. It doesn't provide the "fuel" part of the fire triangle needed to start a fire. Wood mulch and pine straw mulch, however, however, given the nature of the material, ARE flammable. Rubber mulch is also very flammable. Once a heat source is introduced to these varieties of mulch, fire can ignite and be persistent. If the mulch is touching the side of a building that is built using a flammable material like wood siding, the fire could spread.

In a study by the University of Nevada on the combustability of landscape mulch, shredded rubber mulch and pine straw displayed combustion characteristics that were approximately 4 times more volatile than wood chips. Some of the key findings of the study, which measured: 1) average maximum flame height 2) average rate of fire spread and 3) average maximum temperature are here:
  • based on cumulative values, shredded rubber AND pine needles demonstrated the most hazardous fire behavior
  • shredded rubber mulch burned at the hottest average maximum temperature
  • composted wood chips did NOT demonstrate active flaming combustion
  • the most rapid rate of fire spread came from shredded western red cedar mulch

Check out this informative article with video about the flammability of pine straw vs. mulch from ABC11-WTVD North Carolina news. The Chapel Hill NC fire department provides a demonstration that may surprise you.

As a homeowner, you should evaluate the type of home you live in, and decide if your landscape material could be presenting a hazard in the event of an ignition (eg, a smoldering cigarette butt, or a flaming ember blown in from an outside fire). Being aware of your surroundings is the best way to protect yourself and your home in the event of a tragic fire such as the one that happened in Carolina Forest in March 2013.


Comments are closed.