Management of Hot Works: General Best Practice and Special Considerations for Dry Environments

Hot works — including welding, cutting, grinding, brazing, and soldering — are an essential part of many construction, maintenance, and facilities operations. They are also one of the leading causes of workplace fires in the UK. A single stray spark can smoulder undetected for hours before igniting, causing devastating damage and putting lives at risk. Effective hot works management is not just good practice — it's a legal duty under the Regulatory Reform (Fire Safety) Order 2005 and the Construction (Design and Management) Regulations 2015.

What Are Hot Works?

Hot works are defined as any work that generates heat, sparks, or open flame. The most common types include:

• Welding (arc, MIG, TIG, gas)
• Cutting with angle grinders or oxy-acetylene equipment
• Grinding and abrasive cutting
• Brazing and soldering
• Use of blowtorches and heat guns
• Bitumen boiling and roofing work involving naked flames

The Permit-to-Work System

The cornerstone of hot works management is a robust permit-to-work (PTW) system. A hot work permit is a formal, documented authorisation that confirms all necessary precautions have been taken before work begins. It is not a piece of paperwork for its own sake — it is a critical control mechanism that ensures a structured, accountable approach to fire safety.

General Hot Works Management Principles

Regardless of the environment, the following principles should always be applied:

• Eliminate hot works wherever possible — use cold-cutting methods or pre-fabricated components as alternatives
• Conduct a site-specific fire risk assessment before any hot works begin
• Remove all combustible materials from the area, including dust, packaging, and waste
• Seal gaps, openings, and floor drains where sparks could travel to hidden areas
• Use fire-resistant blankets to protect anything that cannot be removed
• Ensure suitable fire extinguishers are immediately available and in date
• Maintain a dedicated fire watch during the work and for at least one hour afterwards
• Brief all workers on emergency procedures and evacuation routes before starting

Special Considerations for Dry Environments

Dry conditions dramatically increase the risk associated with hot works. When vegetation, vegetation, dust, and materials are desiccated by prolonged dry weather, ignition temperatures drop and fire spread accelerates rapidly. The summer of 2022 saw multiple large-scale fires in the UK linked to hot works during drought conditions — a pattern that is likely to repeat as climate change drives hotter, drier summers.

Heightened Risks in Dry Conditions

• Dry vegetation and grass ignite at much lower temperatures and spread fire rapidly
• Dry timber, pallets, and packaging materials have reduced moisture content, making them more combustible
• Dust accumulations — particularly wood dust, grain dust, and paper dust — can form explosive atmospheres when disturbed by sparks
• Low humidity increases static electricity build-up, adding an additional ignition source
• Water supplies and extinguishers may be less effective if water pressure is low during drought periods
• Fire can spread via dry root systems underground, bypassing surface barriers

Additional Controls for Dry Environments

When hot works cannot be avoided during dry conditions, the following additional precautions are essential:

• Extend the fire watch period to a minimum of 2 hours after work completion, with a further check 2 hours later
• Increase the exclusion zone for combustible materials to at least 15 metres
• Damp down the surrounding area with water before commencing work (where safe to do so)
• Use spark-resistant barriers and fire-resistant tarpaulins to contain sparks
• Postpone hot works on days of high wind, which can carry sparks significant distances
• Ensure dust is fully cleaned and removed from the area before any hot works begin
• Notify the local fire brigade in advance for high-risk operations in particularly dry conditions
• Consider relocating hot works to a controlled, indoor workshop environment where possible

Legal and Regulatory Framework

Hot works management is governed by several key pieces of UK legislation. The Regulatory Reform (Fire Safety) Order 2005 (and the Fire Safety (England) Regulations 2022) places a duty on the responsible person to conduct fire risk assessments that account for hot works. The Construction (Design and Management) Regulations 2015 require principal contractors to plan and manage construction work so that risks are controlled — including fire risks from hot works.

Insurance policies frequently include specific hot works warranties requiring a permit-to-work system and fire watch. Failure to comply can invalidate cover, leaving the business exposed to significant financial loss in the event of a fire.

Practical Action Plan

Conclusion

Hot works will always carry inherent fire risk, but with a disciplined permit-to-work system, thorough risk assessment, and vigilant fire watch procedures, that risk can be managed to an acceptable level. In dry environments, the stakes are even higher — sparks travel further, materials ignite more easily, and fires spread faster. By extending exclusion zones, lengthening fire watch periods, and postponing work during adverse conditions, you can protect your people, your property, and your business. If you need support reviewing your hot works procedures or developing a permit-to-work system, Maintain Safety Consulting Ltd can help.