Without proper coating or ignition barrier, what hazard can SPF pose?

• A. No hazard
• B. Rapid flame spread
• C. Structural damage
• D. Water intrusion

Answer: (B)

Without a protective coating or ignition barrier, spray polyurethane foam insulation can ignite and burn quickly. The barrier is there to slow down flames and heat from spreading into hidden cavities; without it, the foam acts as a fuel and flames can travel rapidly across surfaces and through framing. This rapid flame spread greatly increases fire growth, endangering occupants and making it harder to control the fire. Water intrusion and the absence of hazard aren’t the immediate fire-logic risks here, and while a fire can cause structural damage, the key danger the barrier addresses is preventing fast flame spread.