Hot works and poorly managed contractor activity are among the leading causes of serious fires in both commercial and heritage buildings across the United Kingdom.
The consequences of getting it wrong can be catastrophic, as fires at Uppark House, the Glasgow School of Art, and countless commercial and industrial premises have demonstrated over the years.
Yet in many organisations, the management of hot works and contractor activity remains inconsistent, under-resourced, and treated as a procedural inconvenience rather than a critical fire safety function.
This article sets out why hot works and contractor management matter so much, what the law requires, and what a robust management system looks like in practice.
What Are Hot Works?
Hot works are any activities that involve the use of open flames, the generation of heat or sparks, or the application of heat to a surface or structure.
They include welding and cutting, brazing and soldering, the use of blowtorches and heat guns, grinding and disc cutting, the use of bitumen boilers and tar kettles in roofing works, and any other activity that generates sufficient heat to ignite combustible materials.
Hot works are carried out in a wide range of settings, from industrial manufacturing and engineering facilities through to office refurbishments, roofing projects, heritage building restorations, and routine building maintenance.
In every one of these settings, the risk of fire is real, significant, and well-documented.
Why Are Hot Works So Dangerous?
Hot works are dangerous for several reasons that combine to make them a particularly high-risk activity.
The heat, sparks, and flames generated by hot works can ignite combustible materials at a considerable distance from the work location, including materials that may not be immediately visible to the person carrying out the work.
Smouldering fires caused by hot works can remain undetected for hours after the work is completed, hidden within wall cavities, roof voids, insulation materials, or accumulated debris, before breaking out into a fully developed fire long after the contractors have left the site.
The Uppark House fire of 1989, which destroyed one of the National Trust’s most significant properties, is believed to have started from smouldering material in the roof structure hours after roofing contractors had finished work for the day.
Hot works are often carried out in locations that are difficult to access and monitor, including roof spaces, plant rooms, and confined spaces, where the risk of undetected smouldering is particularly high.
And hot works are frequently carried out by contractors who may be unfamiliar with the specific fire risks of the building in which they are working, and who may not have been given adequate information about the fire safety requirements they are expected to meet.
What Does the Law Require?
The legal framework governing hot works and contractor management in the context of fire safety draws on several pieces of legislation.
Under Article 9 of the Regulatory Reform (Fire Safety) Order 2005 (SI 2005/1541), the Responsible Person is required to carry out a suitable and sufficient fire risk assessment that identifies all fire hazards, including those arising from maintenance and repair activities.
Under Article 11 of the RRO, the Responsible Person is required to implement and maintain appropriate fire safety arrangements, including arrangements for the management of contractors and high-risk activities.
Under Article 22 of the RRO, where two or more Responsible Persons share a workplace or building, they are required to cooperate and coordinate with each other to ensure that fire safety obligations are met, including in relation to contractor activity.
The Management of Health and Safety at Work Regulations 1999 (SI 1999/3242) require employers to assess the risks to health and safety arising from work activities, including contractor activities, and to implement appropriate control measures.
Regulation 11 of the Management Regulations requires employers who share a workplace with contractors to provide those contractors with comprehensible and relevant information about the risks to their health and safety and about the emergency procedures in place.
The Construction (Design and Management) Regulations 2015 (SI 2015/51) impose duties on clients, designers, and contractors involved in construction work, including requirements around the management of fire safety risks during construction and refurbishment projects.
And where hot works involve the use of gas equipment, the Gas Safety (Installation and Use) Regulations 1998 (SI 1998/2451) impose additional requirements around the competence of those carrying out the work and the safety of the equipment used.
The Permit-to-Work System
The cornerstone of effective hot works management is the permit-to-work system.
A permit to work is a formal, documented authorisation for a specific high-risk activity, issued by a responsible person who has the knowledge and authority to assess the risks involved and to specify the precautions that must be in place before work can commence.
The Health and Safety Executive’s guidance document HSG250, Guidance on Permit-to-Work Systems, sets out the principles of an effective permit-to-work system and is an essential reference for anyone responsible for managing hot works.
An effective hot works permit-to-work system requires a specific written risk assessment to be carried out before each hot works activity.
It requires the identification and removal or protection of all combustible materials within a specified exclusion zone around the work location, typically a minimum radius of five metres, though this will need to be greater in some circumstances.
It requires the provision of appropriate firefighting equipment at the work location, including a serviceable fire extinguisher of the appropriate type for the materials present.
It requires confirmation that fire detection systems in the vicinity of the work are operational, and that any systems that have been temporarily isolated to prevent false alarms are reinstated immediately after the work is complete.
It requires a mandatory fire watch during the work and for a minimum period after the completion of hot works, typically a minimum of one hour, with many organisations requiring two hours or more depending on the nature of the work and the materials present.
The fire watch must be carried out by a competent person who understands what they are looking for and who has the authority to raise the alarm and call the fire and rescue service if any sign of smouldering or fire is detected.
It requires the permit to be signed off by both the person authorising the work and the person carrying it out, confirming that all precautions are in place before work commences.
And it requires a formal close-out procedure at the end of the work, confirming that the fire watch has been completed, that no signs of fire or smouldering have been detected, and that the work area has been left in a safe condition.
Contractor Vetting and Induction
A permit-to-work system is only as effective as the contractors who operate within it, and the management of contractor competence and behaviour is an essential component of any hot works management framework.
Before a contractor is permitted to carry out hot works on a premises, the Responsible Person should verify that the contractor holds the appropriate qualifications and competencies for the work to be carried out.
For brazing and welding, this includes checking that operatives hold relevant certifications such as those issued by the Welding Institute or the British Institute of Non-Destructive Testing.
For gas work, it requires confirmation that operatives are registered with the Gas Safe Register, as required by the Gas Safety (Installation and Use) Regulations 1998.
For roofing works involving the use of bitumen boilers or torches, it requires confirmation that operatives have received appropriate training in hot works safety.
All contractors and their staff must receive a site-specific induction before commencing work, covering the fire risks present in the building, the location of fire detection and suppression systems, the location of fire exits and assembly points, the emergency procedures to be followed in the event of a fire, and the specific requirements of the hot works permit-to-work system.
The induction must be documented, and contractors must confirm in writing that they have understood and will comply with the requirements.
Supervision and Monitoring
Contractor induction and permit-to-work systems are necessary but not sufficient on their own.
Active supervision and monitoring of contractor activity is essential to ensure that the agreed procedures are being followed in practice and that risks are being effectively managed.
The Responsible Person should appoint a competent person to supervise and monitor contractor activity on site, with the authority to stop work if procedures are not being followed or if a fire risk is identified.
Regular checks should be carried out during the course of the work to confirm that the exclusion zone is being maintained, that firefighting equipment is in place, that the fire watch is being conducted as required, and that no unauthorised hot works are taking place.
Any deviations from the agreed procedures must be addressed immediately, and contractors who repeatedly fail to comply with fire safety requirements should be removed from site.
Managing Multiple Contractors
Many building projects involve multiple contractors working simultaneously or in sequence, and the management of fire risks in these circumstances requires particular care.
Where multiple contractors are present, the Responsible Person must ensure that fire safety information is communicated to all parties, that the activities of different contractors do not create unmanaged fire risks through their interaction, and that clear lines of responsibility for fire safety management are established and maintained.
In larger projects, the appointment of a principal contractor with overall responsibility for site fire safety management, as required by the Construction (Design and Management) Regulations 2015 for notifiable construction projects, provides a framework for coordinating fire safety across multiple contractors.
The principal contractor’s construction phase plan, required under Regulation 12 of the CDM Regulations 2015, must address fire safety risks and the management of hot works, and should be reviewed and updated as the project progresses.
Managing the Risk After Hours
One of the most significant and frequently overlooked risks associated with hot works is the risk of fire developing after contractors have left the site.
The smouldering fires that caused the Uppark and Glasgow School of Art disasters both developed after the working day had ended, in locations that were not adequately monitored after the completion of hot works.
Effective management of this risk requires a rigorous fire watch procedure that continues for an adequate period after the completion of hot works, as described above.
It requires confirmation that all areas affected by hot works have been thoroughly checked before contractors leave the site, including any voids, cavities, or concealed spaces in the vicinity of the work.
It requires that the fire detection system is fully operational before the building is vacated, and that any out-of-hours alarm monitoring arrangements are in place and functioning.
And it requires a clear procedure for what happens if a fire is detected after hours, including who is to be contacted, what actions are to be taken, and how the fire and rescue service is to be called.
Lessons From Major Fires
The lessons from major fires caused by hot works and contractor activity are remarkably consistent.
At Uppark House in 1989, roofing contractors using a blowtorch left smouldering material in the roof structure that developed into a devastating fire after they had finished work for the day.
There was no adequate fire watch procedure, and by the time the fire was discovered it had taken hold throughout the historic roof structure.
At the Glasgow School of Art in 2018, a fire that broke out during ongoing restoration works spread with devastating speed through the partially open historic structure.
Questions were raised about the adequacy of fire safety measures during the restoration works and about the controls in place for managing fire risks in a building that was simultaneously undergoing works and open to partial occupation.
In both cases, a more rigorous approach to hot works management and contractor fire safety could have prevented or significantly limited the damage.
These are not isolated examples.
The Health and Safety Executive and fire and rescue services across the UK respond to significant numbers of fires caused by hot works and contractor activity every year, in premises ranging from domestic properties and small commercial buildings through to major industrial facilities and heritage structures.
The pattern of failure is depressingly consistent: inadequate risk assessment, insufficient exclusion zones, no effective fire watch, and contractors who were not adequately supervised or who did not understand the fire risks of the building in which they were working.
Building a Culture of Hot Works Safety
Ultimately, effective hot works and contractor management is as much about culture as it is about procedure.
Organisations in which fire safety is taken seriously, in which the permit-to-work system is respected rather than circumvented, in which contractors are properly vetted and supervised, and in which the fire watch is carried out diligently rather than treated as an inconvenience, are significantly less likely to suffer a serious fire caused by hot works.
Building that culture requires leadership commitment, clear policies and procedures, adequate training and resources, and a genuine understanding of the consequences of failure.
It requires a Responsible Person who takes their obligations seriously and who has the knowledge, authority, and support to ensure that fire safety standards are maintained consistently.
And it requires contractors who understand that compliance with fire safety requirements is not optional, and who are held to account when they fall short.
The cost of building that culture is modest.
The cost of not building it can be measured in buildings lost, collections destroyed, livelihoods disrupted, and in the most serious cases, lives ended.
We Can Help
At ESI: Fire Safety, we work with building owners, facilities managers, and Responsible Persons to develop and implement robust hot works and contractor management procedures as part of a comprehensive fire safety management framework.
From fire risk assessments that properly address the risks of contractor activity, through to permit-to-work systems, contractor induction documentation, and staff training, we provide the expertise and support you need to manage hot works safely and in compliance with your legal obligations.
If you are concerned about the adequacy of your current hot works management arrangements, or if you are about to embark on a programme of maintenance or refurbishment works and want to ensure that fire safety is properly managed throughout, get in touch with our team today.
Further Reading and Key Legislation:
Regulatory Reform (Fire Safety) Order 2005 (SI 2005/1541): https://www.legislation.gov.uk/uksi/2005/1541/contents/made
Management of Health and Safety at Work Regulations 1999 (SI 1999/3242): https://www.legislation.gov.uk/uksi/1999/3242/contents/made
Construction (Design and Management) Regulations 2015 (SI 2015/51): https://www.legislation.gov.uk/uksi/2015/51/contents/made
Gas Safety (Installation and Use) Regulations 1998 (SI 1998/2451): https://www.legislation.gov.uk/uksi/1998/2451/contents/made
HSE Guidance on Permit-to-Work Systems (HSG250): https://www.hse.gov.uk/pubns/books/hsg250.htm
HSE Hot Work guidance: https://www.hse.gov.uk/fire/hotwork.htm
Historic England guidance on fire safety in historic buildings: https://historicengland.org.uk/advice/technical-advice/fire-safety
National Fire Chiefs Council fire safety guidance: https://nfcc.org.uk
This post is intended as a general guide. Always seek advice from a qualified fire safety or legal professional for guidance specific to your premises and circumstances.
