Inside Risk: Mitigating the risk of hot works

Hot works continue to be one of the main causes of substantial fire loss in commercial premises, resulting in property damage, business interruption, and potential loss of customers. It can ignite combustible materials nearby and potentially more distant from the work area during or after the hot work activities.

Ideally, hot work activities should be avoided through use of alternative work practices. Where it is essential, however, robust controls should be implemented to ensure the risk of fire is reduced as much as possible. In some cases, insurers include policy conditions regarding the control of hot work.

What is hot work?

Hot work involves any process using open flames, sparks or heat producing tools or equipment, such as (opens a new window):

  • Welding and cutting equipment

  • Blow lamps or torches

  • Hot air ‘guns’ or blowers

  • Bitumen or tar boilers

  • Angle grinders and grinding wheels

  • Brazing and soldering

Where combustible materials are present, the risk of fire is increased. Combustible materials might include storage, equipment, furnishings, or construction material such as timber frames or wall insulation products.

Hot work loss examples

The high-risk nature of these activities mean it is essential for a business to have an effective hot work permit system and follow safety procedures. Without this, insurers may not pay out in the event of a claim – if it’s relevant to the loss.

With that in mind, here are a few different examples of multi-million dollar hot works losses:




A plastic tarpaulin was ignited by a gas torch used in a school during the summer holidays. The fire spread rapidly and most of the building was destroyed. No hot work permit was in place, highlighting a lack of mitigation against the risk of fire, along with several other failings.


A contractor had been conducting hot work in a school. A fire watch must remain in place for at least an hour after work has finished for the day, but the contractor left the site before the fire watch period had elapsed. During this time, a fire took hold. Although there was a hot work permit in place, it had been prepared by the contractor with no oversight from the school.


Combustible materials ignited during roof work on a two-story building that housed a library and IT facilities. The fire was spotted quickly, but spread rapidly, destroying the building completely. While a generic permit for a larger program of works was in place, it wasn’t a hot works permit specifically created to manage the associated fire risks. The hot works permit was kept in the contractor’s cabin – the only person who saw it also issued it.

Source: Zurich Insurance, 2020 (opens a new window)

While unfortunate, these cases are avoidable. It’s clear that merely preparing a hot works permit is insufficient – it’s a safety system that should identify, assess and improve the risk for all individuals involved in hot works, whether indirectly or directly.

Mitigating the risk of hot work

A robust hot work process and permit system should be established to manage any activities using open flames, sparks or heat producing tools or equipment.

Key considerations include:

  • Hot work permit system – develop a formal, written hot work permit system, managed by one or more competent supervisors. A hot work permit should be for a specific task within a specific area over a specific duration (not for protracted periods). Additional guidance and example permits can be accessed through the Fire Protection Association (FPA) (opens a new window), National Fire Protection Association (NFPA) (opens a new window) and insurers.

  • Consider safer alternatives – only conduct hot works where a safer work process is not available. Consider conducting the work in safe location outside, or in a dedicated hot work area.

  • Training & equipment – ensure personnel are trained, equipment is in good condition and is used appropriately. The FPA provide a free Hot Work Site Induction toolkit (opens a new window).

  • Use of contractors – ensure adequate contractor controls are in place including processes for contractor selection, competency, review of insurance, method statements and risk assessments, induction, and training.

  • Fire protection – ensure sprinklers remain in service. Limit the size and duration of any required fire detection impairments.

  • Fire watch – provide a continuous fire watch during and following the work to detect any fires or hot spots. The extent and duration of the fire watch should be extended as necessary based on the risk assessment.

  • Before the hot work – ensure a robust risk assessment is conducted with the work area cleared and/or protected. Provide suitable firefighting equipment. Ensure hot work is not conducted in areas with explosive atmospheres.

  • After the hot work – ensure the area is cleared of waste and equipment while maintaining a continuous fire watch. Additional checks may also be needed at regular intervals for longer periods. Assess the work area following completion of the work.

  • Documentation – work permits should be returned, checked, and retained for future reference.

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Inadequately controlled hot work activities can lead to a large loss. To help manage the risk of hot work, develop, and implement a robust hot work system in collaboration with your broker and insurer.

For further information, please visit the Lockton Risk Control page (opens a new window).

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