Much about mulch: spontaneous combustion

Out of control mulch fire in Helotes, Texas (February 2007)

Mulch, stored in huge piles 10 to 20 feet deep, has been known to build up enough heat from internal decomposition to start a fire. Near the tiny Texas town of Helotes, a huge mulch fire burned for three months before it died out in March 2007.


     Spontaneous combustion occurs when a substance generates enough heat to ignite without an outside source. The fire triangle consists of heat, fuel, and oxygen. Ignition of fire requires not only a combustible material but also oxygen, generally from air, and usually an energy source to provide ignition, although certain materials other than mulch can also spontaneously ignite. Once combustion has begun in a mulch pile, the smoldering fire can become deep-seated and spread rapidly. The larger and taller the mulch pile, the greater the fire hazard and the more difficult a fire in such a pile will be to control.

Large piles of mulch can result in combustion. Weight of mulch compacts mulch at the 
center and can cause pile to ignite. Massachusetts State law requires piles be 
25 feet from other piles. Companies that store or manufacture more than 300 cubic yards
must obtain permit from municipal fire department.

Combustion and fires can occur even in frigid conditions.
Fires burned for almost a week at a Macedonia, Ohio, landscape business.
Highlight photo to read news article.

From the Massachusetts Department of Fire Services laws:
Storage and Manufacturing of Mulch - The revised regulation has safety requirements for those who store or manufacture mulch. It limits the size of mulch piles and requires a distance of 30-feet between piles and 25-feet from the lot line. Large piles of mulch can easily spontaneously combust with all the heat they generate. The distance between piles prevents a fire in one from easily spreading to another or to a building.

Permits Required to Store 300+ Cubic Yards of Mulch - Permits are required from the fire department wherever more than 300 cubic yards of mulch is produced or stored.

Firefighters battled a mulch fire at J.D. Raymond Transportation, a Peabody (MA) mulch yard, 
in 2010.  The fire followed a 2008 mulch fire at an apartment complex that caused $6.7 million
in damage. The new state regulations also cover mulch storage and manufacturing.

 

Watch video from another state

Will there be a day when Framingham 
may have to put up signs such as this??

Highlight photo to go to related article.

Mulch piles appear to be smoldering at Landscape Depot. Of particular concern is the intensity
of a mulch fire heating the soil below and igniting the coal tar. Property sits on a vast 
peat bog that, if ignited, can continue to burn for decades. 
(photo taken September 30, 2014)