I have a building with a wood frame wall. Exterior covering his sheet metal. The interior covering is plywood. Vegetation has grown from the exterior into the wall and died. An expert is saying the following as to spontaneous ignition taking place. The temperature on the day of the fire was 77°F and the humidity was 35%. There was a wind of approximately 18 mph.


Spontaneous Combustion is a self-heating process that is generally associated with chemical or biological reactions that produce heat as a byproduct. In biological processes, such as in drying haystacks and composting materials, microorganisms produce heat during the digestive process that can result in fire causation. Decomposition or rotting of a material is also associated with heat production, self-heating, and spontaneous combustion. Wind (such as on the day of the fire) or increased oxygen inflow can contribute to transition from self-heating to open flame ignition.

The presence of substantial wood root and decay was evident in the east wall of the boiling room and evidence of dry vegetative material was also evidenced on the property. This provided conditions that are favorable to spontaneous combustion and this theory cannot be eliminated.

I am curious if anyone has information on spontaneous combustion inside of a wall as described above taking place.

Jim Mazerat
Forensic Investigations Group