A well-insulated farm building helps keep its occupants comfortable and productive. But the type of insulation you choose in building or renovating an ag building like a farm shop, livestock barn, or processing facility may cause increased risk of fire.
That is why understanding the different types of insulation is a key step in determining how to strengthen fire safety. Plastic spray foam insulation has become popular in farm and agricultural buildings because of its thermal efficiency and its ease of installation. But when installed incorrectly, it can create new fire risk in addition to potential negative health effects.
Here are key factors to consider when selecting plastic spray foam or other insulation:
- Consider product combustibility as a factor in your purchasing decision
- Look for formulations labeled as slow-burning
- Follow manufacturer’s instructions for installation, including covering it with a thermal barrier
- Consider worker health and potential health impacts of insulation or building materials
Why plastic spray foam insulation adds to fire risk
In a building fire, plastic spray foam insulation can speed the spread of flames and smoke. This poses a serious threat to the safety of a building's occupants. Plastic spray foam insulation can also affect the building's loss potential and insurability.
Some types of spray foam insulation may be marketed as “fire resistant.” This doesn’t always mean the product won’t burn, according to Nationwide Senior Risk Management Property Engineer Ryan Michalek.
“Some plastic spray foam insulation is made with fire-retardant chemicals. There’s a common misconception that these products do not burn, but all plastic spray foam insulations will burn. Some formulations burn less aggressively than others,” Michalek said. “To minimize fire risk, look for a slow-burning and low smoke-emitting classification on plastic spray foam insulation.”
Plastic spray foam insulation fire ratings
Plastic spray foam insulation is categorized by its surface burning characteristics. For fire safety, building codes require the use of spray foam insulation that is rated by third-party testing as “slow-burning.” The American Society for Testing and Materials (ASTM) E84 test shows how fast flames will spread and how much smoke is emitted when burning. Insulation rated Class A (Class I) burns the slowest and emits less smoke, while Class C (Class III) burns rapidly and emits lots of smoke.
Add a thermal barrier
Most plastic spray foam insulation must be covered with a 15-minute thermal barrier to reduce fire risk. This normally means covering the insulation with ½-inch sheetrock. But other more durable materials like plywood or sheet steel can be used in hard-use buildings like livestock barns and machinery shops.
A thermal barrier gives building occupants time to get out in the event of fire. It also lessens the likelihood of accidental ignition of the plastic spray foam. Building codes usually require even slow-burning plastic spray foam insulation to be covered with a thermal barrier. Always follow the manufacturer’s installation instructions and install a thermal barrier when prescribed.
Consider potential health impacts
Insulation may contain fire-retardant chemicals which can cause health concerns. Take the steps necessary to protect your employees and be aware of the risks associated with insulation and building materials.
Talk to your building contractor to choose the right insulation for your construction or renovation. To learn more about insulation risks and ways to minimize them, contact our risk management team.