Can a pile of fresh wood chips spontaneously combust?

[sixdogs]

We used to play in sawdust piles when it was common for timber to be sawed on location with circular sawmills. I remember a fresh one steaming when we dug into it after a rain.

I would be chipping spruce limbs from the dark center of rows of trees. Not much sun in there so some are dead and some are living but very little green involved. Just chipped branches.

 

[Jstpssng]

It's becoming a practice here to grow Cole products in greenhouses in winter, with only compost for heat. When I worked for a landscaper years ago we would pack grass clippings into trash bags after mowing clients lawn. We never had a fire, but at the end of a hot day could see that the clippings were turning to ash. I don't believe that should be as much of a concern in the OP's case unless he's adding a lot of water and green manure. Wood is a bit more stable.

Here's an interesting story about heat from compost... in early horse racing days the jockeys were required to stay under a certain weight. A track down in Mexico had a huge manure pile from all of the race horses there. Jockeys would go out and bury themselves to the neck, letting the heat from the composting manure act like a sauna to sweat some weight off.

 

[stuckmotor]

I've read of people burying water tubes in piles of wood chips to extract heat and looping the tubes under trays in greenhouses. If there's a fire hazard I don't know that it's worth the risk.

 

[MoKelly]

It's becoming a practice here to grow Cole products in greenhouses in winter, with only compost for heat. When I worked for a landscaper years ago we would pack grass clippings into trash bags after mowing clients lawn. We never had a fire, but at the end of a hot day could see that the clippings were turning to ash. I don't believe that should be as much of a concern in the OP's case unless he's adding a lot of water and green manure. Wood is a bit more stable.

Here's an interesting story about heat from compost... in early horse racing days the jockeys were required to stay under a certain weight. A track down in Mexico had a huge manure pile from all of the race horses there. Jockeys would go out and bury themselves to the neck, letting the heat from the composting manure act like a sauna to sweat some weight off.

That is just disgusting. Hard to imagine.

MoKelly

 

[RalphVa]

Yep. With the right amount of greenery to start things cooking, especially if out in the sun with its help.

 

[stuckmotor]

That is just disgusting. Hard to imagine.

MoKelly

They must have smelled awful.
Another thing I've read about is tramps in Victorian times burying themselves in manure piles to stay warm. I hope the manure was rather dry and they were between some kind of blankets.

 

[Alan W.]

There was a mulch pile that spontaneously combusted in Lexington this last year.
So yes it can happen. How likely who knows.

 

[user.69169]

20 acre leaf mulching site here where towns all dump yuppie leaves dat can't be chopped into lawn of house about to get foreclosed. Guy walks around every other day wid thermometer taking pile temperature. Pile gets hot dey bring in machine dat stirs de pile so it don't light off.

 

[jaxs]

The sulution is quite simple,rather than piles 10w x 5T,spread to no higher than 3'. Put you hand inside 2 days later to check heat. If you can stand to keep your hand buried for 60 secounds you can proceed to pile higher. If it feel's super hot,weight until composting slows before building higher piles. What will you eventually do with wood chips?

 

[sixdogs]

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.