Preventing Hay And Straw Barn Fires
The threat of rain might convince you to get the hay baled and into the barn as soon as possible, even if the hay hasn’t dried down enough. That decision also increases the risk of a fire due to spontaneous combustion of hay bales that are too wet.
Tim Schnakenberg is a regional Extension agronomy specialist at the University of Missouri. He says high moisture content in hay bales encourages the growth of naturally-occurring bacteria.
"Some of those bacteria can form into some heat-loving bacteria. During the curing process and after the hay has been rolled up, it can start to escalate out of control. That is, if the moisture level is excessive," he says. "So, we’re trying to keep moisture level no higher than 20% if at all possible."
If you’re concerned that hay may have been baled at too high a moisture content, frequently monitor the internal temperature of several bales for the first six-weeks after baling. He says spending $100 on a thermometer is a lot cheaper than replacing a barn destroyed by fire.
"If it gets above 130 or 140-degrees, you really want to monitor it. If it’s over 150, it may just continue to climb and it probably needs to start to come out of the barn to improve air circulation. And they say that at 175 degrees Fahrenheit, fire is a strong possibility," says Schnakenberg.
He says bales with a lower density that are stacked in a way that allows good air flow and ventilation have a lower risk of overheating.
Find more tips for preventing hay barn fires