Hot Work Permits That Prevent Rooftop Fires

Rooftop torch-down jobs, emergency pipe soldering, or welding support steel near HVAC units all share the same risk: fire that starts out of sight and spreads through insulation before anyone notices. Hot work permits exist to control that risk, but they only work when everyone takes the process seriously. Here is how to keep sparks from becoming claims.

Pre-Plan Every Hot Work Task

Walk the work area before issuing a permit. Look for combustible insulation, tar paper, roofing adhesives, and hidden voids. Remove combustible materials within 35 feet or protect them with fire-resistant blankets. When removal is impossible, wet down surfaces or shield them with sheet metal. Document photos of the prepped area so you can prove you followed NFPA 51B guidance.

Assign Competent Permit Issuers

Side-stepping the permit because "it will only take a minute" is how most roof fires begin. Designate authorized employees who understand the building systems, roof construction, and impairment notifications. They must verify controls before issuing the permit, stay accessible during the job, and close the permit only after the fire watch clears the area. Rotate responsibilities so vacations do not halt work—or tempt workers to run without a permit.

Define Fire Watch Duties Like a Job Description

Fire watch employees must be trained to recognize ignition sources, use extinguishers, and call emergency services. They must have no other duties during hot work and must remain in place for at least 60 minutes after work stops (longer if the job involved decking or insulation). Provide radios or phones, extinguishers sized for the hazard, and an agreed-upon way to summon help. Record their names on the permit.

Coordinate Building Systems

Disable fire detection or suppression systems only when necessary, and coordinate with the monitoring company and local fire department. Log the impairment start/end times, zones affected, and compensatory measures (additional patrols, temporary detectors). Once systems are restored, document testing results. This paper trail saves you when insurers or AHJs review the event.

Control Weather and Ventilation

Wind can carry sparks under flashings and into hidden cavities. Set weather limits for rooftop hot work—suspend tasks when wind speeds exceed your threshold or when thunderstorms are forecast. For indoor work, ensure ventilation is adequate to control fumes without spreading sparks. Record the conditions on the permit so you can explain decisions later.

Close the Permit With Evidence

When the job ends, the permit issuer and fire watch should inspect the area together. Use infrared thermometers to check for hot spots beneath roofing membranes. Only close the permit when both sign off. File permits for at least three years or per your insurer’s requirement. Patterns in the paperwork reveal whether crews are following the process or cutting corners.

Next step: Build digital hot work permits inside Worksafely SMB to attach photos, track fire watch names, and send automatic reminders for post-work inspections.