Hot works including welding, burning, grinding, and brazing are a major cause of fire on construction sites. A hot works permit is required before any task that produces heat, sparks, or flame in areas where combustible materials could be ignited. The permit system ensures the area is prepared, controls are in place, and a fire watch is maintained. Failure to follow the permit process has led to devastating site fires causing millions of pounds of damage and loss of life.
Key Hazards
Fire from hot sparks or slag igniting combustible materials nearby
Burns to skin and eyes from welding arc, flame, and hot metal
Toxic fume inhalation from heated metals, coatings, and fluxes
Explosion risk when hot works are carried out near flammable substances
Control Measures
Obtain a signed hot works permit before starting any task involving heat, sparks, or open flame.
Clear all combustible materials within a minimum radius of 10 metres of the hot works area.
Use fire-resistant sheets and welding curtains to contain sparks and protect surrounding areas.
Ensure a suitable fire extinguisher is within immediate reach of the hot works location.
Maintain a continuous fire watch during hot works and for a minimum of 60 minutes afterwards.
Check the area above, below, and behind the hot works position for hidden combustible materials.
Ensure adequate ventilation is provided to remove fumes, especially in enclosed or confined areas.
Wear appropriate PPE including welding visor, fire-resistant gloves, and flame-retardant clothing.
Close out the permit formally with the issuing authority when all fire watch periods are complete.
Emergency / Rescue
If a fire starts during hot works, raise the alarm, attempt to extinguish with the available extinguisher only if safe to do so, and evacuate the area. Call 999 and report to the assembly point.
Remember
Hot works cause more construction site fires than any other single activity.
The fire watch must continue for at least 60 minutes after hot works are completed.
Sparks from grinding and cutting can travel up to 10 metres and ignite hidden materials.
Never carry out hot works without a valid, signed, and displayed permit in place.
Check areas above, below, and behind your work position for combustible materials beforehand.
A single hot spark in the wrong place can destroy an entire building under construction.
Applicable Legislation: Regulatory Reform (Fire Safety) Order 2005 · Health and Safety at Work etc. Act 1974 · CDM Regulations 2015 · Dangerous Substances and Explosive Atmospheres Regulations 2002