If the work makes a flame, a spark or enough heat to ignite what is around it, the answer on almost every managed site is yes. Welding, cutting, grinding, brazing, soldering, torch-on roofing, hot bitumen, a blowtorch on a pipe joint: all of it is hot work, and the fires it starts usually start after the operative has packed up and gone.
Where the requirement comes from
No regulation contains the words "hot works permit". The requirement arrives from two directions. The Joint Code of Practice on fire prevention on construction sites, which insurers write into the policy on most contracts of any size, requires hot work to be carried out under a permit system with a fire watch afterwards. Separately, DSEAR 2002 requires an employer to control ignition sources where a dangerous substance could be present, and the general duty to plan and manage the work sits under CDM 2015 and the Management Regulations.
So the honest position is this: the law requires the risk to be controlled and the insurer requires the permit, and a principal contractor who lets hot work happen without one has put the building's insurance at risk as well as the building.
What the permit actually does
A hot works permit is not a form that says "allowed". It is a sequence with named people:
- Someone describes the work — what, where, for how long, with which equipment.
- The area is checked before the permit is issued — combustibles moved or covered, floor and wall openings sealed, extinguishers to hand, detection isolated if it has to be and a record made of that.
- One person issues, another accepts — the issuer confirms the precautions, the person doing the work signs that they understood them.
- The work happens inside the permit's time window — a permit is for a shift, not a week.
- A fire watch follows — someone stays in the area after the work stops for the period the Joint Code sets, then a final check later.
- The permit is closed — signed off, area returned, detection restored.
The fire watch is the step that gets skipped, and it is the step that matters. Torch-on felt smoulders in the insulation for an hour before anything shows.
Common questions from the approving side
A heat gun stripping paint? It is heat applied to a surface that can char and ignite. Treat it as hot work.
Soldering a single joint in a plant room? Still hot work. The permit takes ten minutes; the plant room is full of lagging.
Grinding outdoors? Sparks travel several metres. If there is anything combustible in range, permit it.
Can a subcontractor issue their own permit? The issuer should be someone who controls the area and knows what else is happening in it. On a site with a principal contractor, that is normally their appointed person, not the trade doing the work.
What a template does not do
The permit gives the sequence, the checklist and the signature chain. It does not know your building or who on your site is competent to issue it. Those decisions stay with your competent person, and no document makes anyone compliant. Why we will never call a document "compliant".
Documents for this work
- Hot Works Permit — the permit, the pre-work checks and the sign-off chain
- Fire Watch Certificate — the record of the watch after the work stops
- Toolbox Talk — Hot Works — the five-minute briefing before the first permit of the job
- The Permit to Work Suite — every permit and the system around them