A hot works permit is a time-limited authorisation for work that produces heat, sparks or flame in a place where that is not normally happening: welding, cutting, grinding, brazing, soldering, roofing with torches. Insurers ask for them, principal contractors demand them, and most firms treat them as a form. They are actually a short safe system of work with the highest-value clause at the end, which is what happens in the hour after the tools go down.
What the permit exists to control
Three things. The area: what combustible material is within range of sparks and hot metal, including things behind and below the work, in voids, and on the other side of a wall or a floor. The equipment and the person: competence, condition of the gear, and the isolation of anything that would make a fire worse. And the detection: whether fire alarms are being isolated for the work, who authorised that, and what compensating watch is in place while they are off.
The checks that have to be true before it is issued
Combustibles removed or protected, with a stated clearance. Openings, voids and gaps sealed or covered. Extinguishers present and appropriate, with someone who can use them. Detection status known and recorded. Isolation of process materials confirmed. And a nominated fire watch, named on the permit, who is not the person doing the work. If the permit is signed and any of those is a plan rather than a fact, the permit is describing an intention.
The hour after the work is the part that burns buildings down
Most hot work fires start after the work has finished, from smouldering material that was heated during the job and takes time to develop. That is why permits carry a post-work watch period and a final inspection, and why the permit is not closed until both have happened. A firm that issues permits and closes them the moment the welder packs up has kept the paperwork and dropped the control that matters most.
Permits are records, and their value is retrospective
The permit's use during the job is real but short. Its long value is evidential: proving, to an insurer or an investigator, that this specific work on this date was authorised, that these checks were made and that the watch was kept. That only works if the closed permit is kept where it can be found, against the site and the job, which is a records problem rather than a form-design problem.
Questions people ask about hot works permit
What is a hot work permit?
A written, time-limited authorisation for work producing heat, sparks or flame, issued after specific fire precautions have been confirmed in place, and closed only after a post-work watch and a final check of the area.
Who issues a hot work permit?
Someone authorised by the organisation controlling the premises, who is competent to check the precautions and independent of the person doing the work. On a construction site that is usually the principal contractor's nominated person; in an occupied building it is normally the facilities or safety manager.
How long should the fire watch continue after hot work?
Long enough for smouldering to become visible, and the period should be stated on the permit rather than left to judgement. Insurers commonly specify a period and it is often longer than firms expect; whatever period you adopt, the point is that the permit stays open and the area is checked again before it is closed.