When the world's largest commercial property insurer quantifies a risk, contractors should pay attention. FM Global Data Sheet 10-3 contains decades of loss-prevention data showing that the difference between a well-managed hot work program and a poorly managed one isn't marginal — it's a 41-to-1 ratio in fire losses. The majority of these fires trace back to the same source: outside contractors working without adequate oversight.
The 41-to-1 Gap
Facilities with well-managed hot work programs average $123,000 in fire losses. Facilities with poorly managed programs see losses 41 times greater — averaging over $5 million. The difference isn't equipment or technique. It's program discipline: permits, fire watch, and post-work monitoring.
The Contractor Problem
FM Global's data shows the overwhelming majority of hot work fires are caused by outside contractors. The risk more than doubles when contractors work without facility oversight. This is the highest-risk scenario in commercial hot work — and the one where documentation matters most.
The 60-Minute Window
Most hot work fires occur during work or within 60 minutes of completion. That's the post-work monitoring period that NFPA 51B and OSHA require — and the period most likely to be cut short due to production pressure. Timed, verified check-ins during this window are the only way to prove the watch was actually maintained.
Source: FM Global Data Sheet 10-3