Hot Works Permit: What It Must Cover and Why the Fire Watch Matters
Pro Site Docs · Guide
Most construction fires do not start during the hot work. They start an hour after it, in a void or behind a board, when the site is quiet. That is why a hot works permit is not about the cutting or the welding. It is about what happens before it and, above all, what happens after.
Where the requirement comes from
There is no regulation called 'hot works permit'. The duty sits in the Regulatory Reform (Fire Safety) Order 2005 for premises in use, in CDM 2015 regulation 29 (prevention of risk from fire), and in the general duty to have a safe system of work. The document that turns those into a permit is the Joint Code of Practice on the Protection from Fire of Construction Sites and Buildings Undergoing Renovation (the JCoP), published by the Fire Protection Association. Most main contractors adopt it, and most insurers require it on projects above a set value. Once it applies, a hot works permit is mandatory on that site.
What counts as hot work
Anything with an open flame, spark or heat source that can ignite the surroundings: welding, cutting, grinding, brazing, soldering, torch-applied roofing, bitumen boilers, heat guns and blowlamps. The one people forget is grinding, because the sparks travel further than anyone thinks and land where nobody is looking.
What the permit has to record
- Exact location and the work to be done - not 'roof', but 'north elevation, bay 3, torch-on felt to upstand'
- Who is doing it, and their competence for that method
- Can it be avoided? The JCoP expects hot work to be the last option. Cold-applied systems, mechanical fixings and off-site cutting come first
- The area cleared - combustibles removed or protected within a stated distance, typically 10 metres, and openings, voids and drains covered
- Fire-fighting equipment at the point of work - the right extinguishers, checked, and the person who knows how to use them
- A named fire watcher who does nothing else while the work is on
- Start and finish times - a permit for a shift, not a week
- The fire watch after completion, with the time it ends and a signature to close the permit
The 60-minute fire watch
The JCoP requires a fire watch to continue for at least 60 minutes after hot work stops, with a final check of the area before the site is left. Some insurers and main contractors require longer - two hours is common on roofing - and the permit should state whichever figure applies. The reason is simple: smouldering in insulation, timber or debris often takes that long to become a visible fire. A permit that is signed off the moment the torch goes out has skipped the part that prevents most losses.
Hot work should also finish early enough for the full watch to happen before the site closes. Torch-on roofing at 4.30pm on a site that shuts at 5 is a permit that cannot be honoured.
Who issues and who closes it
An authorised person for the contractor in control of the area issues the permit after walking the location - not from the cabin. The person doing the work accepts it. At the end, the same authorised person (or a named deputy) inspects, confirms the fire watch has been completed, and closes it with a signature and time. An unclosed permit is treated as live work.
Where it goes wrong
The permit issued for 'the site' for 'the week'. The fire watcher who is also the labourer. Grinding done without a permit because 'it is only a couple of cuts'. The watch abandoned at knocking-off time. And the extinguisher that was on the permit but was actually on the other side of the building. Each one appears regularly in fire investigation reports, and each is a line on the permit that was signed without being true.
Get the documents ready-made
Our Permit Systems Pack includes a hot works permit built around the JCoP, alongside permits to dig, work at height and confined space entry, or take individual permit templates.
19 editable Word documents: hot works, permit to dig, confined space, working at height and isolation permits, with issue and close-out sections.
See the permit packWritten by Pro Site Docs from HSE guidance and the regulations named in the text. Published 3 September 2026. Check the current legislation and guidance for your own situation.
Keep reading
General guidance only. This article explains how the rules generally work in UK construction. It is not advice for your specific site, task or project, and it is not legal advice. Your own risk assessment, method statement and arrangements must be prepared and checked by a competent person for the actual work being done.