Can a pile of fresh wood chips spontaneously combust?

[Egon]

Many a barn with slightly damp hay in the loft has burned down.

 

[Alien]

I saw a hay barn go up once. Took the tractor and other machinery with it. Dad used to sprinkle salt between each layer of hay to prevent it from happening.
I saw a string mop that burnt up once. It was leaning against a wall on a concrete floor. Fire dept came to check it out. Quite intriguing.
If people can spontaneously combust, no reason a pile of compost wouldn't.

 

[Davegc2]

These people say the piles need to be bigger than 60'x100'x10' or so so you might be safe. https://s0.hfdstatic.com/sites/the_hartford/files/wood-chip-mulch-storage.pdf
I know I had a 6' deep pile that was steaming hot the other day so I was wondering too.

 

[turnkey4099]

For the last ten years or more - I thin and chip my "baby" pine stands. 900 to 1200 small pines every spring. So......... I have piles of chips all over my 80. The piles will never get as big as what you have there Sixdogs. I let the chips fall where they may. A "pile" could be 20 feet long - 3 feet wide - have a MAX depth of one foot.

Bottom line - I've never had any of them get any hotter than the prevailing conditions. No smokers - no flames.

However - I HAVE seen the results of a hay stack "explosion". THEY said it was spontaneous something or other.

I would keep an eye on that five foot pile. If it starts getting warm/hot - - spread it out to a much thinner pile. Maybe a foot deep and spread out.

I built a compost pile (my first) with shredded bark mixed in with lots of cow pats. Wasn't long before it was smoldering.

I "noodle" firewood rounds too big for me to lift. That produces lots and lots of shavings that look like noodle. Neighbor raises chickens and loves those for bedding and nesting material. I pack it tight in big black garbage bags and warn her about the possibility of spontaneous combustion. Hasn't happened yet but any combustible material cut down into shavings or sawdust can do it given a bit of moisture.

 

[turnkey4099]

I worked at an agricultural equipment factory. Final step in the process was into the paint shed for a good coat. The floor had to be scraped periodically toremove the builup of paint. Painter did that one day and put the scrapings into the dumpster. Yep, fire dept came put it out and barely saved the building.

 

[mapper]

I'm the OP on this and decided the risk of spontaneous combustion is a risk I don't want to take. As mentioned, I'm chipping understory branches deep in rows of shelter belt trees and it's too tight to get anything more than the tractor w/chipper in. No trailer for the chips. I figured to leave the chips in the trees to dry for a while and then bucket out to burn. A fire deep in those trees would be an inaccessible mess. So, I'll chip now and bucket them out ASAP.


For other spontaneous issues, when we baled small square hay bales I remember an exact number number of days and temperature to watch for. We had a12" probe thermometer and you had to watch for a temperature range that I've forgotten but it was around the 11th day +/- after baling and maybe 125 ish degrees with a probe in the center of the bale. If a fire was to occur it was around the 17th or 18th day, more or less but I can't recall the exact days. I know those are pretty exact numbers but I double check things and it was spot on for small bales of timothy/grass hay. Advice would have come from Univ of Maine @ Orono or Maine Extension Service if you want to check it out.

Why not just spread them around where you chip them, they will feed the trees as they break down and help build up the soil?

 

[CobyRupert]

Yes. I think many a wood/chip yard at a paper plant has caught fire. I believe they can burn for days/weeks/months and many places have fire pumps and hose systems nearby.

 

[jyoutz]

Yep. I’ve seen several chip pile fires at sawmills. In fact many mills have sprinklers on the chip piles.

 

[jyoutz]

Why not just spread them around where you chip them, they will feed the trees as they break down and help build up the soil?

As long as they aren’t more than about 2” deep. Otherwise they impede growth of forest plants and don’t break down very fast.

 

[orangetree]

our fresh piles of wood chips, one large utility truck's worth (maybe 5'tall, 8'wide, 12' long) would smoke, and be uncomfortably hot inside. This in a mild climate, with plenty of water, and never covered.

I don't think you'd need too many variables 'worse' to get ignition: significantly hotter, drier days (it never got above 90, and had humidity), perhaps a perfect balance of material & moisture in the pile, etc. Or especially a pile twice the size.