Hot works permit and risk assessment
Last updated 17 October 2026
A hot-works permit is the permission to start. The risk assessment is why that permission has conditions. One does not replace the other.
A hot-works risk assessment identifies what can burn, who is nearby, and how the job will stop a fire starting or spreading. The permit is the check that those controls are in place before anyone strikes an arc or lights a torch. A site-ready RAMS your principal contractor can review includes both the assessment and the point where work stops if the permit conditions are not met.
The hot works RAMS template starts from combustibles, cylinders and the fire watch.
Worked example
Lead flashing on a chimney, with a felted flat roof beside the stack and a timber loft below:
- Combustibles are moved or protected. The felt edge is shielded before the torch is lit.
- A suitable extinguisher is at the point of work, and someone who knows how to use it is there.
- Gas cylinders are stored upright, outside the loft, and checked for leaks before the hose is pressurised.
- The permit is signed when the area is ready, not the night before.
- The fire watch stays after the flame is out, including a check of the loft. The job is not “finished” when the lead looks done.
What the law is asking for
- Management of Health and Safety at Work Regulations 1999. Assess the fire and explosion risk from this activity and apply the controls.
- Dangerous Substances and Explosive Atmospheres Regulations 2002, where a dangerous substance can create a fire or explosion risk.
- Regulatory Reform (Fire Safety) Order 2005, for the responsible person in non-domestic premises. A hot-works job does not sit outside those fire precautions.
- Construction (Design and Management) Regulations 2015, when the work is construction. HSE’s HSG168 is the guidance on fire safety in construction. It is not itself a regulation.
- Control of Substances Hazardous to Health Regulations 2002, if the task also creates fume that people can breathe.
Questions
Is the permit the risk assessment?
No. The permit records that the conditions are in place for this shift. The assessment says what the fire hazards are and which controls the permit is checking.
How long does a fire watch last?
Long enough for the site and the materials involved. The assessment should set the period for this job, including after the torch is out. Do not copy a time from another building without looking at this one.
Does a domestic plumbing job need a permit?
If the work can start a fire, the hazards still have to be controlled. A principal contractor will usually want a permit. A domestic client may not have a permit system, which means you still need the assessment and a written check before the torch is lit.