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Common Causes of Barn Fires

Understanding how barn fires start makes it easier to spot problems before they grow. This is general information, and local fire officials can tell you what matters most in your area.

Why look at causes at all?

Fires seldom start for mysterious reasons. They usually begin with a small problem that was known or visible: a damaged cord, a heater too close to bedding, damp hay or an unattended job. Knowing the common causes gives you a checklist.

Exact figures and rankings differ across sources and years, so I will not quote any. Look to NFPA and extension for current information.

Treat every warning sign as important. Many fires follow days or weeks of small signs that nobody acted on.

• Known problems left unfixed
• Small warning signs ignored
• Habits that go unchecked

How do electrical problems start fires?

Aging wiring, damaged insulation, loose connections, overloaded circuits and improper fixtures can create heat or sparks. In barns, dust, moisture, rodents and animals add to the problem.

Signs include warm outlets, flickering lights, tripped breakers, burning smells and chewed wires. If you see them, shut off power at the source if it is safe and call an electrician.

Never replace a breaker or fuse with a larger one to stop it from tripping, since the trip is telling you about a problem.

• Flickering lights or frequent tripped breakers
• Warm or discolored outlets
• Burning or hot-plastic smell
• Damaged, chewed or exposed wires
• Do not replace a breaker with a larger one
• Shut off power at the source only if it is safe

What about heating equipment?

Heat lamps, space heaters and tank heaters can ignite bedding or dust if they fall, touch flammable material or run without supervision. Faulty or homemade equipment is a particular concern.

Follow the maker's instructions and your fire marshal's advice. Choose equipment made for the use, and keep clear space around it.

If you use heated waterers or other heated devices, have them checked each season and replaced when damaged.

• Tank heaters and heated waterers need checking too
• Replace damaged or homemade equipment

How does hay cause fires?

Hay stored too moist can heat up through natural processes and, in some cases, ignite. This is called spontaneous combustion, and it is covered in its own article here. Fires can start days or weeks after baling.

Check with your extension office on moisture testing and monitoring, and follow the official guidance you can find on the eXtension and National Agricultural Safety Database pages.

• Moisture testing guidance from extension
• Monitoring of stored hay
• Fires can start days or weeks after baling

What other human causes should you watch for?

Smoking, welding, cutting, grinding and open flames are common human causes. So are arson and children playing with matches or lighters. Machinery that is parked hot in a barn can also be a cause.

Set clear rules, supervise hot work and keep ignition sources away from hay and fuel. Make sure children know that matches and lighters are not toys.

Keep a gate or lock on barns where possible, and make sure children and visitors understand the rules.

• Supervise welding and grinding
• Keep ignition sources away from hay and fuel

What about lightning and weather?

Lightning can ignite buildings directly or through electrical systems. A lightning protection system installed by a qualified professional may be an option. Ask your fire department, insurer or electrician what suits your buildings.

Storms can also cause power surges and downed lines. Keep an eye on the forecast and have an emergency plan for storms.

Talk with your insurer about any lightning protection they recommend or require, and who should install it.

• Ask about lightning protection by a qualified installer
• Check the forecast and plan for storms
• Know the main shutoff

How can you use this on your farm?

Walk through each building with this list. Look for damaged wiring, heat sources, stored hay, fuel and habits that could start a fire. Write down what you find and fix the most serious items first.

Invite the fire department to give feedback, and revisit the list every season. Share what you find with family and workers.

Keep records of what you fixed and when, since a record shows progress and helps the fire department understand your buildings.

• Walk each building with a checklist
• Fix the most serious item first
• Record what you fixed
• Share the checklist with family and workers
• Revisit it every season

Last reviewed: November 12, 2026. Written by the Farm Safety Editorial Team. See our editorial policy.