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Hot work permit: the fire watch is the part that matters

A hot work permit is mostly about what happens after the welding stops. Most hot work fires start in the hour nobody was watching.

How-toH

A hot work permit authorises work producing heat, sparks or flame — welding, cutting, grinding, brazing, soldering, torch-applied roofing — outside a designated area built for it. It is the most commonly issued permit type on ordinary sites, and the one whose conditions are most often treated as boilerplate by people who have done the job a hundred times without incident.

The reason it exists is specific: sparks travel further than people expect, they lodge in places nobody inspects, and they smoulder. The fire usually starts after the work has finished and everyone has moved on, which is why the fire watch and the post-work checks — not the welding itself — are the part of the permit that earns it.

What a hot work permit requires

  • The exact location, the equipment and the work, plus confirmation that it cannot reasonably be done in a designated hot work area or by a cold method instead.
  • The area cleared of combustibles within a defined radius, and anything immovable covered with fire-resistant material.
  • Openings, cracks, ducts and floor penetrations covered — sparks fall through the gaps first.
  • The other side of any wall, floor or ceiling checked, because conducted heat ignites what is on the far side.
  • Fire extinguishing equipment present, appropriate to the materials, and known to be in date.
  • Detection considered: whether an alarm needs isolating to prevent a false activation, and the compensating watch if it does.
  • A named fire watch during the work, with no other duties.
  • The continued watch after work stops, for the period your policy or insurer requires, and a final check some time later.
  • Validity period, issuer, acceptor and the sign-off closing the permit.

The fire watch is a role, not an instruction

A fire watch with a second job is not a fire watch. The person needs to be free of other duties, positioned where they can see the areas sparks can reach — including the far side of a partition and the level below — equipped with the means to raise the alarm and to use an extinguisher, and briefed on when to stop the work rather than deal with it. The commonest arrangement in practice, where the welder watches their own work, fails at exactly the moment it matters, because the welder is under a hood looking at an arc.

The post-work period is where the losses happen. Insurers commonly require a continuous watch for a period after the work ends plus a further inspection afterwards, and claims are refused where the permit says one thing and the record shows the site was locked at the moment the watch was supposed to be running.

Contractors, insurers and the paperwork that follows

Most hot work on a site is done by contractors, and most disputes afterwards are about who authorised what. Insurance policies frequently impose hot work conditions directly — permit required, watch duration, no hot work in the final period of the working day — and non-compliance can be a coverage question rather than a safety one. Keep the issued permits, the fire watch record with times, the contractor’s competence evidence and the post-work check together: Ettex Records holds that file per site and per contractor, Ettex Forms captures the pre-start checks and the watch sign-off at the location, and the wider system it belongs to is covered in permit to work.

To be clear: this is records and forms, not fire safety advice. Clearance distances, watch durations and detection isolation are set by your fire risk assessment, your regulator and your insurer — and where those three differ, the strictest one is the one to follow.

Frequently asked

When is a hot work permit needed?

For heat, spark or flame-producing work outside a designated hot work area — welding, cutting, grinding, brazing and torch-applied roofing among others.

How long must a fire watch continue after hot work?

For a period set by your policy, insurer or regulator after work stops, commonly followed by a further inspection later. Confirm the requirement that applies to you rather than assuming an hour.

Can the welder act as their own fire watch?

No. The watch must be free of other duties and able to see where sparks can reach, which a person under a welding hood cannot be.

Does the permit cover the other side of the wall?

It should. Conducted heat ignites materials on the far side of partitions, floors and ceilings, and checking that side is a standard permit condition.

DK
Written by Daria K.

Part of the Ettex team — writing about product, engineering and the future of work.

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