So, my story has a barn that was set on fire. No accelerants were used (a few ounces of gasoline at the site of ignition, but that's it). The barn has in it a few bales of hay, a cord or so of firewood (not dried) that was stacked against the wall, and whatever else you might find in a barn. Early attempts to put it out where made my hauling buckets of water to the fire a few gallons at a time, but ultimately were unsuccessful. There is no fire department or any such to put out the fire.
How long will this fire burn for? Not so much how long until every last smoldering ember is out, but until it appears to be no longer raging? Also, how long before the building (all wood construction) collapses? And finally, what are the risks of the fire spreading, if it's on moist land covered mostly with live grass and no nearby trees?
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36,051 / 50,000
Nov 8, 2009 - 12 03
Okay, I have to admit to a bit of 'male answer syndrome' (i.e., I'm admitting I don't really know). But hey - - - my dad was a fire fighter for 30 years, so I'm sure I've heard stories.
Length of time will depend on amount of fuel, type of fuel, etc. For instance if your barn was stuffed to the rafters with hay or cotton or whatever, it would burn longer. I remember my dad taking me to see a burning cotton mill when I was a child. It burned for several days. However, your building is mostly empty, and not so large.
The building will probably be fully involved within 15 - 30 minutes. Depending on size or roof beams, etc. I think you could have your roof collapse in anywhere from 1 - 3 hours. The whole thing would probably burn itself out - as you said, excluding embers, etc. within 8 hrs or so. Some walls, parts or walls, bits of roof may stay up.
Any real firefighters out there - not just sons of? Please chime in.
43,156 / 50,000
Nov 11, 2009 - 04 14
I once burned down a barn on accident... was a teenager and dad said to burn the dead weeds so one thing led to another and.....
First, the chance of a fire like that spreading are very high. A barn with hay. Unless the ground is clean dirt or cement (most have a few layers of older hay or straw in them) then what happens is the fire will smolder underground using hay (and if there were ever animals, manure) as fuel. We had stuff catching fire a month after we thought it was out. Even if the dirt looks like dirt, if there is any traces of dried animal dung, it will smolder and smolder for a long time, spreading underground until it finds something else to grab on to. It doesn't matter how moist the ground is, it will spread.
Firewood would burn hot and the building would most likely fail at that spot first. Bails of hay burn for a long time due to their compact nature.
You are very likely to find old tractors in barns. the tires and hoses would burn and oil and gas would leak and accelerate the fire further. it wouldn't blow up.
Animals would.. .okay, I'm going to assume that the animals are not going to burn, but many barns have horses or chickens in them.... Herbivore droppings = accelerate (and massive underground smoldering).
Anything rubber (lots of rubber in barns... tires, hoses, chemical containers, tractor implements) will burn hot with a oily black smoke.
We didn't have a fire department to put out the barn. I started the fire at about five in the afternoon. by five thirty it was an inferno. By Nine it was no longer raging. The next morning at around five (so twelve hours later) there was still smoldering and pockets of flame. Everything seemed to be dead by lunchtime (of course the underground blaze was with us for months.... every once in a while there would be a little plume of smoke rising from a patch of grass... it was odd. Like living in hell or something)