Hot works on commercial roofs: permits, insurers and flame-free options
Updated 23 October 2026 · SEO Dons Editorial
Check your re-roof against the rules ↓
Hot works on a commercial roof means roofing work that brings flame, heat or sparks to a building whose roof build-up may contain combustible material. This guide is for the owner or facilities manager deciding whether to allow it, what paperwork to ask for and when to specify a flame-free system instead. It covers England, Wales and Scotland, not Northern Ireland.
Is a hot works permit a legal requirement?
No statute prescribes a form called a hot works permit. The duty is wider and sits in the fire risk assessment. In England and Wales, article 9 of the Regulatory Reform (Fire Safety) Order 2005 requires the responsible person to make a suitable and sufficient assessment of the risks to which relevant persons are exposed, and to keep it up to date. Article 11 requires arrangements for the effective planning, organisation, control, monitoring and review of the preventive and protective measures. Articles 9 and 11 do not mention permits. A permit is one way of putting those arrangements into practice for a risky job, and the HSE cautions that a permit is not a replacement for robust risk assessment and that the issue of a permit does not, by itself, make a job safe.
In Scotland the duties are in the Fire (Scotland) Act 2005. Section 53 requires an employer to assess the workplace for fire risks to employees, and section 54 extends the assessment duty to a person with control of relevant premises.
The construction rules sit alongside. Regulation 29 of the Construction (Design and Management) Regulations 2015 requires suitable and sufficient steps to prevent the risk of injury during construction work from fire or explosion, and regulation 9 requires a designer to eliminate foreseeable risks so far as is reasonably practicable. The NFRC says its Safe2Torch campaign is designed to support specification writers in complying with CDM 2015. The CDM 2015 guide for a commercial re-roof covers the client duties.
Who carries the duty on a let or managed roof?
The responsible person is the employer for a workplace under their control, or otherwise the person in control of the premises for a business, or the owner where the person in control is not running a business there (article 3). Article 5 goes further. It extends the duties to anyone with control of the premises to any extent, and treats a person with a contract or tenancy obligation for repair or maintenance as having control to the extent of that obligation. On a multi-let building, landlord, agent and tenant can each hold part of the duty, so say who does what.
What counts as hot work on a commercial roof?
The Fire Protection Association (FPA) defines hot work as any activity that involves the use of open flames or the application of heat or friction in a temporary setting. Its examples include roofing, liquid petroleum gas, hot air guns, cutting, grinding and welding. On a roof the usual cases are:
- torch-on reinforced bitumen, where a gas torch melts the membrane to bond it, and torching to dry out a roof, which is what the NFRC's Safe2Torch campaign targets;
- bitumen boilers, since the HSE notes that LPG is widely used in connection with them;
- cutting, grinding or welding on plant, flashings or metal sheets during the same job.
Hot-air welding of single-ply seams uses heated air, not a flame, yet the FPA's list of hot work examples includes hot air guns. Ask the insurer rather than assume. Mastic asphalt is different again. The Mastic Asphalt Council (MAC) says solid blocks are preheated in boilers at ground level and that at no time is there any type of naked flame at the point of installation. That is a trade body describing its own material, so still ask about the boiler. The mastic asphalt repair, overlay or replace guide covers the roof itself.
Who issues and signs a hot works permit?
The HSE describes a permit to work as a formal system stating exactly what work is to be done and when. A responsible person assesses the work and checks safety at each stage, and the people doing the job sign to show they understand the risks and precautions. The FPA says the permit must be completed by a competent person and signed by both that person and the contractor doing the work.
Neither source says which role on the owner's side must issue it. Name the role in the contract and the fire risk assessment, and make sure that person can stop the job. A roof permit should record:
- the exact work, area and time window, with the roof left in a safe state if the job spans shifts;
- cleared combustibles, suitable extinguishers and a careful watch throughout, which are the HSE's basic hot work precautions;
- the fire watch after the work, and any extension to it;
- hand-back and sign-off, since the HSE says a permit system should have a process for hand-over on completion.
How long must a fire watch last?
The FPA says a fire watch must be present and continue for 1 hour after the task has been completed. It may be extended in high-risk areas such as timber-framed buildings, or areas with lots of cavities, confined spaces, flammable or combustible materials, and anything beyond 1 hour must be documented on the permit. An insurer may set a longer period, so treat one hour as a starting point.
What do insurers expect?
There is no single published insurer standard for roofing, so rely on the policy. The FPA publishes RC07, Risk Control for Hot Work (listed as published 10 March 2023), good practice guidance for property protection that includes a hot work permit and checklist. The MAC reports increasing pressure from insurance companies and building owners over fire risk, with some banning naked flame on roofs altogether. The Liquid Roofing and Waterproofing Association (LRWA) says many liquid systems are now totally cold applied and seen as a safe alternative by insurers, main contractors and specifiers.
Tell the insurer what is planned, ask in writing whether hot work is allowed on the roof and on what conditions, and give the contractor that answer before tender. A permit does not override a policy condition.
When should the specification go flame-free?
The NFRC's Safe2Torch rule is a good test. Identify all fire risks at survey stage and factor them in before the specification is written. Where a fire risk has been identified, or cannot be ruled out, the relevant parts of the specification must default to torch-free solutions. If it is later demonstrated that an area is safe, for example when an area is uncovered during a refurbishment, the specification can, if all parties agree, revert to torch application. The FPA agrees: hot work should only be carried out if there is not a safer alternative.
| Option | Flame or heat source on the roof | What to ask |
|---|---|---|
| Torch-on reinforced bitumen | Gas torch | Permit, fire watch, Safe2Torch checklist completed before work starts |
| Self-adhesive or cold-applied felt | Compared in the torch-on, cold-applied and self-adhesive felt guide | Method statement, and the fire classification of the whole build-up (see the BROOF(t4) guide) |
| Hot-air welded single-ply | Heated air, no flame | Whether the insurer counts hot air guns as hot work |
| Cold-applied liquid | None, per the LRWA | Adhesion testing and the certificate; see liquid-applied roofing and PMMA, polyurethane and GRP |
| Mastic asphalt | Molten material, boilers at ground level | The insurer's view of the boiler and hot delivery |
If the roof is heading for refurbishment rather than repair, the commercial flat roof refurbishment page explains how overlay, recover and strip options differ.
What should the tender and contract say?
- Record the roof's fire risks at survey, and make torch-free the default wherever the risk cannot be ruled out.
- Name who issues permits, the minimum fire watch and who keeps the records, and send the insurer the specification.
- Ask tenderers for method statements and for confirmation that supervisors will complete the Safe2Torch checklist before hot works commence, a pledge commitment under the NFRC campaign.
- Ask about competence. The FPA runs a Hot Work Passport scheme, valid for five years from the course, according to its page.
To compare flame-free routes for your own roof, you can send roof details through the form on the refurbishment page.
Sources
- legislation.gov.uk, Fire Safety Order 2005, checked 22 October 2026
- legislation.gov.uk, Fire (Scotland) Act 2005, checked 22 October 2026
- legislation.gov.uk, CDM 2015, checked 22 October 2026
- HSE, Permit to work systems and Process fire risks, checked 22 October 2026
- Fire Protection Association, What is a hot work passport? and RC07 listing, checked 22 October 2026
- National Federation of Roofing Contractors, Safe2Torch, checked 22 October 2026
- Mastic Asphalt Council, Flame-free roofing solutions with mastic asphalt, checked 22 October 2026
- Liquid Roofing and Waterproofing Association, Liquid applied waterproofing FAQs, checked 22 October 2026
Common questions
Is a hot works permit the same as a fire risk assessment?
No. The fire risk assessment is the legal document that identifies the risks and precautions. A permit is a job-specific control used to apply them on the day, and the HSE says it is not a replacement for robust risk assessment.
Can a tenant be responsible for fire precautions during landlord roof works?
Possibly. Under article 5 of the 2005 Order, anyone with control of the premises to any extent, including a person with a repair or maintenance obligation under a contract or tenancy, carries duties for matters within that control. Check the lease and agree the procedure in writing.
Does a flame-free roofing system need a permit?
That depends on the fire risk assessment and the insurer. A cold-applied system removes the naked flame, but cutting or grinding on plant or metal sheet may remain, so ask the contractor and insurer to confirm which operations do.
Can torch-on felt be used again once a roof is specified torch-free?
The NFRC says it can revert to torch application if an area is demonstrated to be safe, for example once uncovered, and all parties agree. Record that decision in the project file.
Related guides
Check your re-roof against the rules
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