How to Write a RAMS for Hot Works: Welding, Cutting and Grinding

What Counts as Hot Works?

Hot works is any task that produces sparks, open flames, or heat above 100°C. On a typical construction site, that includes:

• Welding (MIG, TIG, MMA, and oxy-fuel)
• Grinding and cutting with abrasive discs

• Gas cutting and brazing
• Soldering and lead work
• Torch-on roofing felt application

If the activity generates enough heat to ignite surrounding materials, it falls under the hot works category and requires specific risk controls in your RAMS.

Why Hot Works Need Their Own RAMS

Hot works are the leading cause of fire on construction sites. That alone justifies a dedicated RAMS rather than folding fire risk into a general document.

Sparks from grinding and welding can travel up to 10 metres horizontally, and even further when falling vertically through open structures. Molten slag can lodge in gaps, insulation, or cable trays and start smouldering fires that only ignite hours after the work has finished. This delayed ignition is what makes hot works fires so dangerous: the workforce may have left the area, or even the site, before the fire takes hold.

The Regulatory Reform (Fire Safety) Order 2005 places a legal duty on the responsible person to assess fire risk and implement appropriate controls. For hot works, that means your RAMS must go beyond standard PPE and method statements to cover fire prevention, detection, and post-work monitoring.

Hot Works Permit System

Most construction sites require a hot works permit before any welding, cutting, or grinding begins. The permit is a formal record that the area has been inspected, combustibles have been removed or protected, and fire prevention measures are in place.

Key points to include in your RAMS regarding the permit system:

• A permit must be obtained before work starts each shift. Permits are valid for one shift only.
• The permit must be cancelled and signed off at the end of the work period, confirming the fire watch has been completed.
• The fire watch must continue after work stops. The permit should not be signed off until the fire watch period is complete.
• If work moves to a different location, a new permit is required for the new area.

Your RAMS should reference the permit system so that every operative understands that no hot work begins without a live permit.

Key Hazards for Your RAMS

Your hot works RAMS should address these specific hazards:

• Fire from sparks and molten slag landing on combustible materials, including materials stored below or behind the work area
• Burns to operators and nearby workers from direct contact with hot metal, sparks, or radiant heat
• UV radiation from arc welding causing arc eye (photokeratitis) in operators and bystanders who look at the arc without protection
• Welding fumes containing manganese, chromium, and other hazardous substances (see our COSHH assessment for welding fumes guide for detailed controls)
• Explosion risk when working near flammable materials, gas lines, fuel stores, or in areas where flammable vapours may accumulate
• Confined space risks including oxygen depletion from gas shielding, toxic fume buildup, and reduced escape routes in the event of fire

Control Measures

Your RAMS should detail specific, practical controls for each hazard. Here are the critical areas to cover.

Fire Prevention

• Clear all combustible materials within a 10 metre radius of the work area. This includes packaging, timber, insulation, and stored materials.
• Cover gaps, openings, and penetrations with fire blankets to prevent sparks from travelling to other compartments or floors.
• Damp down combustible surfaces that cannot be moved, such as timber decking or formwork.
• Position a suitable fire extinguisher within 5 metres of the work area. For most hot works, a water or foam extinguisher is appropriate, with a CO2 extinguisher available for electrical equipment.

Fire Watch

• Maintain a fire watch for a minimum of 1 hour after all hot works have stopped. Some insurers and principal contractors require a 2 hour fire watch.
• The fire watcher must have a suitable extinguisher and know how to use it. They should also carry a radio or phone to raise the alarm immediately.
• Check the immediate area and all adjacent spaces, including above, below, and behind the work location.

PPE Requirements

• Welding visor or auto-darkening helmet appropriate to the welding process (shade number matched to the arc type)
• Flame-resistant overalls or clothing. Standard hi-vis polyester can melt onto the skin and must not be worn during hot works.
• Welding gauntlets that protect hands and forearms from sparks, spatter, and radiant heat
• Safety boots with heat-resistant soles to protect against molten metal splash

Exclusion Zones

• Set up physical barriers and signage around the hot works area to prevent unauthorised access
• Use welding screens or curtains to protect other workers from UV flash. Even brief exposure to an unshielded arc can cause arc eye.
• Communicate hot works zones at the daily site briefing so all trades are aware of the active work areas

The Fire Watch: The Part That Saves Lives

The fire watch is the single most important control in any hot works RAMS. It is the last line of defence against a fire that starts after the welding torch has been put down.

The minimum fire watch period is 60 minutes after all hot works have stopped. Many insurers and principal contractors require 120 minutes, particularly for work on or near roofs, in buildings with combustible insulation, or on refurbishment projects. Check your site-specific requirements and your company insurance policy before setting the duration in your RAMS.

The fire watcher should be a dedicated person who remains in the area for the full duration. They need a suitable fire extinguisher, a means of communication (radio or mobile phone), and knowledge of the site fire alarm and evacuation procedure. Their job is to monitor the work area and all adjacent spaces, including areas above, below, and behind the work location where sparks or heat may have travelled.

Document the fire watch completion. Record the time it started, the time it finished, and the name of the fire watcher. This record should be attached to the hot works permit and kept on file. If a fire investigation ever takes place, this documentation demonstrates that your controls were followed.

Generate Your Hot Works RAMS

Writing a thorough hot works RAMS from scratch takes time. SwiftRMS generates a complete, project-specific RAMS for hot works in minutes, covering fire prevention controls, PPE requirements, exclusion zones, and a linked fire watch checklist. Try it free and see the difference a structured, professional RAMS makes on your next hot works job.

For more on how permits integrate with your RAMS, see our permit to work guide.

Related Guides

• COSHH Assessment for Welding Fumes
• Construction Phase Plan Guide
• Permit to Work Guide
• What Is a RAMS Document?

Hot Works on Occupied Buildings

Carrying out hot works on an occupied building introduces additional risks that go beyond the standard precautions. People may be working, sleeping, or visiting the building while welding, cutting, or grinding takes place nearby. The consequences of a fire in these circumstances are far more serious, and your RAMS must reflect that.

Before any hot works begin, you should establish a formal liaison with the building manager or facilities team. They need to know exactly when the work will happen, where it will take place, and what fire precautions you have in place. This is not optional. In most commercial and public buildings, the building manager holds responsibility for fire safety under the Regulatory Reform (Fire Safety) Order 2005, and your activities must be coordinated with their fire strategy.

One of the most common requirements is fire alarm isolation and reinstatement. Hot works often produce smoke, dust, or heat that can trigger fire detection systems. To avoid false alarms (and the disruption they cause), specific detector heads or zones may need to be temporarily isolated. Your RAMS should detail who is responsible for arranging the isolation, the process for reinstating detectors once work is complete, and the interim fire safety measures that will apply while the system is impaired. Detectors must be reinstated at the end of each working day without exception.

Building occupants should receive advance notification about the planned hot works. This might be done through signage, emails to tenants, or direct briefings. People in the building need to know that smoke or unusual smells may occur, and crucially, they need to understand that the fire alarm may be partially disabled during certain hours.

Insurance requirements are another critical factor. Many commercial property policies reference the Joint Fire Code (published by the Fire Protection Association and the Association of British Insurers) or JCT contract conditions that impose strict hot works controls. Non-compliance can void fire insurance cover entirely. Check the building's insurance conditions before starting any hot works, and keep records that demonstrate full compliance.

For occupied buildings, the fire watch period is often extended. Where one hour post-work might be acceptable on an empty construction site, insurers and building managers frequently require a minimum of two hours of fire watch after the last hot works activity in an occupied building. Your RAMS should state the extended duration and confirm that a named individual will remain on site for the full period.

Torch-On Roofing: Special Considerations

Torch-on roofing (also called torch-applied felt roofing) is one of the leading causes of commercial building fires in the UK. The combination of an open flame, combustible roofing materials, and work that often takes place out of direct supervision makes this a particularly high-risk activity. If your project involves torch-on roofing, the RAMS needs to address the specific hazards involved.

The core risk is bitumen ignition. Bitumen-based roofing membranes have a flash point that can be reached if the gas torch is held in one position for too long or used at excessive temperatures. The ignition temperature of bitumen varies by grade but is typically between 300 and 400 degrees Celsius. Operatives must be trained to keep the flame moving and to recognise the early signs of overheating.

Work near the roof edge and rainwater outlets requires extra care. Flames directed towards or near upstands, drains, and gutters can ignite debris or damage plastic fittings. Keep the flame a safe distance from these features, and clear any accumulated leaves, litter, or other combustible material before starting work.

Gas cylinders stored on the roof must be kept upright, secured against falling, and positioned well away from heat sources. Only the minimum number of cylinders needed for the day's work should be taken onto the roof. Spare or empty cylinders should be stored at ground level in a well-ventilated area. Cylinder valves should be closed when not in active use, even during short breaks.

Weather conditions matter more for torch-on roofing than for most other hot works. Wind affects flame control significantly, potentially directing the flame towards unintended areas or making it difficult to maintain consistent heating. Your RAMS should set clear wind speed thresholds above which torch-on work must stop, and operatives should be empowered to make that call without pressure to continue.

Sample Hot Works Permit Content

A hot works permit is a formal, written authorisation that confirms all necessary precautions are in place before any hot works activity begins. It is not just a tick-box exercise. A well-written permit acts as a final check and provides a clear audit trail. Here is what a good hot works permit should include:

• Location of work (specific area, floor, room, or grid reference)
• Description of the task (type of hot work, equipment to be used)
• Name of the operative carrying out the work and their relevant qualifications
• Date and time the permit is valid (permits should never be open-ended; a maximum of one shift is typical)
• Fire precautions taken (confirmation that the area has been inspected and prepared)
• Combustible materials cleared or protected (details of what was removed, covered, or dampened)
• Fire extinguisher type and location (which extinguisher is immediately available and where it is positioned)
• Fire watch duration (the agreed monitoring period after hot works cease)
• Cancellation sign-off (a signature confirming the fire watch was completed and no hazards remain)

The permit should be displayed at the work location for the duration of the task. Once cancelled, permits must be retained on file as part of the project's safety records.

Frequently Asked Questions

Do I need a hot works permit for using an angle grinder?

Yes, in most cases. Angle grinders produce sparks and hot particles that can travel several metres and ignite combustible materials. They are classified as hot works under most site safety policies and insurer requirements. The same permit process, fire precautions, and fire watch apply as for welding or cutting.

What about soldering copper pipe?

Soldering with a blowtorch is classified as hot work. Although the flame is smaller than that used in welding or cutting, it is still an open flame capable of igniting nearby timber, insulation, or dust. Many building fires have started from plumbing soldering work carried out without proper precautions. A hot works permit is required, and fire-resistant protection should be placed behind and around the joint being soldered.

Can the welder also be the fire watcher?

No. The fire watcher must be a separate, dedicated person whose sole responsibility is to monitor for signs of fire. The operative carrying out the hot work is focused on the task at hand and cannot simultaneously observe all areas where sparks or heat may have travelled. The fire watcher should have no other duties during the hot works and must remain in position for the full fire watch period after the work ends.

What fire extinguisher should I have for hot works?

At minimum, a CO2 extinguisher and a water extinguisher (or water mist extinguisher) should be immediately available at the point of work. CO2 is suitable for electrical and flammable liquid fires, while water tackles fires involving solid combustible materials such as timber and cardboard. The fire watcher should be trained in how to use both types.

How far do sparks travel from grinding vs welding?

Sparks from angle grinding can travel up to 5 metres or more depending on the material and disc speed. Welding spatter typically reaches 2 to 3 metres, but oxy-fuel cutting can throw molten slag up to 10 metres or further, especially when working at height. Your exclusion zone and fire protection measures should be sized based on the specific activity, not a generic one-size-fits-all distance.

Authority Sources and Further Reading

For further guidance on managing hot works safely, the following external resources provide authoritative and detailed reference material:

• Joint Fire Code (FPA/ABI) – The definitive standard for fire prevention on construction sites and in occupied premises. Includes specific requirements for hot works permits and fire watch procedures.
• RISCAuthority Guidelines – Technical guidance documents from the Fire Protection Association's risk arm, covering hot works, fire safety in construction, and loss prevention.
• HSE Hot Work Guidance – The Health and Safety Executive's official guidance on controlling fire risk from hot works activities.
• British Standard BS 9999 – Code of practice for fire safety in the design, management, and use of buildings. Relevant to hot works planning in occupied premises.

You may also find these related guides from Swift helpful:

• Welding Fumes COSHH Assessment
• Permit to Work Guide
• Working at Height RAMS
• What Is a RAMS Document?
• Construction Phase Plan