Pyrolysis

[begreen]

Pyrolysis comes up often in posts. I thought it would be good to have a dedicated thread on the topic. The second part of this article has some good info on pyrolysis.

A former chimney sweep and fire investigator says that pyrolysis has been the cause of over 85% of the fires related to solid fuel that she has investigated. Other causes of fires include:

• Improper maintenance of a chimney, appliance, pipe, or connector is the cause of 10 of every 100 fires she has studied.
• Careless or improper operation of a heating system or appliance has caused about 5% of the fires she investigated.

https://www.ctsweep.com/blog/top-sweep-stories/two-little-known-causes-of-house-fires/

Here are a couple examples of near misses with pyrolysis under hearths that were inadequate for the stove. Never cut corners with clearances and hearth protection.

 

[huauqui]

begreen, thanks for providing us with this information. Always good to be reminded of potential hidden dangers with our stoves.

 

[marajade]

The other recent thread with the charred wood in the chimney chase totally freaks me out
Thanks

 

[BobUrban]

thanks Bgreen - what are we looking at in pic #2? I am now re-inspecting my clearances even though I have multiple times before.

 

[begreen]

thanks Bgreen - what are we looking at in pic #2? I am now re-inspecting my clearances even though I have multiple times before.

IIRC that is the floor darkening from a simple hearthboard used under a stove that needed much greater protection.

 

[Sawset]

When I was a kid coming in from the outside we would put our wet gloves on the hot duct work next to the oil furnace downstairs. Often times we would next day find the gloves were scorched, semi burnt. By code ductwork even today needs to be by one inch below combustibles six feet from the plenum. You could check that downstairs probably right now on your furnace. 130 degrees is the the threshold of pain, and those ducts were hot. At 200deg dry aged wood that has been previously charred can spontaneously combust. A quick check here, now, with a stovetop of 500, stack temp of 850, all areas around the stove are cool to the touch, as well as the classA up in the attic. Adds to a sense of confidence.