Key points to cover
- A written hot works permit must be issued before any hot work begins — no permit, no work
- Clear all combustible materials within at least 10 metres of the hot work area, or protect them with fire-resistant sheeting
- Ensure a dedicated fire watch is maintained during hot works and for at least 60 minutes after work finishes
- Have suitable fire extinguishers (CO₂ and water) immediately available at the hot work location
- Check the area below, above, and on the other side of walls or partitions — sparks travel through gaps, ducts, and service penetrations
- Never carry out hot works in areas where flammable liquids, gases, or dusts are present without a full risk assessment and gas-free certification
- Ensure smoke detection systems in the area are managed during hot works (notify fire alarm monitoring, do not simply isolate)
Do's and don'ts
Do
- Obtain a hot works permit before starting any welding, cutting, grinding, or brazing
- Clear combustible materials at least 10 metres from the work area and protect anything that cannot be moved
- Post a trained fire watch during and for at least 60 minutes after the hot work finishes
- Check below, above, and behind the work area for combustible materials and hidden voids
- Keep appropriate fire extinguishers within immediate reach of the hot work area
Don't
- Never start hot work without a valid permit, even for a 'quick job'
- Never leave hot work unattended — if you need to leave, stop work and maintain the fire watch
- Never carry out hot work near flammable liquids, gases, or dusts without gas-free certification
- Never disable fire detection systems without following the agreed management procedure
- Never assume the area is safe after hot works finish — smouldering fires can ignite hours later
Questions to check understanding
Q1: What is a hot works permit and when is it required?
Show the answer
A hot works permit is a formal written authorisation for work that produces sparks, flames, or heat (welding, cutting, grinding, brazing). It records the precautions to be taken, the duration of the work, the location, and the person responsible. Treat every hot work job as needing a permit, however short or 'minor' — the Joint Code of Practice requires one for all hot work once fitting-out has started on site and in any building being refurbished, and your site rules may go further.
Q2: How long should a fire watch be maintained after hot work finishes?
Show the answer
A fire watch should be maintained for at least 60 minutes after hot work finishes. The Joint Code of Practice on fire prevention on construction sites (10th edition, 2022) recommends this as a minimum, followed by further checks. During the fire watch, the area must be continuously monitored for signs of smouldering or fire, and suitable extinguishing equipment must remain immediately available.
Q3: What minimum clearance distance should be maintained for combustible materials around a hot work area?
Show the answer
All combustible materials should be cleared to a minimum distance of 10 metres from the hot work area. Where materials cannot be removed, they must be protected with fire-resistant sheeting or screens. This includes checking above, below, and on the other side of walls, floors, and ceilings.
This is general guidance for UK construction sites. Check it against your own risk assessment, method statement and the site before you deliver it.