Hot work

[edit] Introduction

The term ‘hot work’ refers to processes that require the use of open flames or that produce sparks through heat and friction that could ignite into a fire. Hot works include:

• Riveting.
• Welding.
• Flame cutting.
• Brazing.
• Soldering.
• Thawing.
• Grinding and drilling (when flammable materials are present).
• Use of any equipment that incorporates a flame.

Hot works can pose a significant fire risk, from both the initial risks of ignition and as a cause of rapid fire spread. According to BS 9999, only if no satisfactory alternative method is feasible should hot work be undertaken.

Precautions should include:

• Carrying out the hot work outdoors or in specially-designated areas that minimise fire risk if possible.
• Scheduling hot works during periods when other works are quieter.
• Applying safe systems for undertaking the hot works.

In 2020, it was reported that research indicated hot works were to blame for 79% of all fires on construction sites in Scotland during the previous year. Ref http://www.constructionmanagermagazine.com/news/construction-firms-warned-hot-works-fire-risk/

[edit] Hot work permit

BS 9999 recommends that a ‘hot work permit’ be followed in order to ensure actions are taken to mitigate and minimise risks before, during and after the works. The permit is appropriate when there are flammable materials in close proximity to the works, and when the work environment is not ordinarily used for such activities.

The permit is used:

• To ensure there is a formal check confirming appropriate work processes are being adhered to.
• To provide time limits for safe working.
• To provide for special PPE (personal protective equipment) or communication methods.
• For coordinating work activities.
• To ensure proper supervision throughout.

When being employed to complete hot works contractors may be required to use the client’s hot work procedure, or they may use a suitable procedure of their own. In the case of the latter, the client must ensure that the contractor is using a suitable hot work procedure.

There are varying levels of risk depending on the type of work and the area within the building that it is taking place. As a result, the hot work permit system should be adapted to the particular needs and risks. In terms of the proposed works, the permit should be designed to provide as much information as possible.

Typically, the hot work permit will identify:

• Administrative details (permit title, number, job location, etc.).
• Description of the work to be undertaken.
• The person/s carrying out the work.
• Likely length of time to complete the work.
• Identified hazards and required precautions.
• Work methods that are required.
• Types of fire-fighting equipment available.

In addition, the permit will identify the requirements that must be met within the work area which include the following:

• Combustible materials removed before work commences.
• Floors swept clean and combustible surfaces covered with heat protections mats.
• Walls covered and combustibles moved away.
• Elimination of explosive atmosphere in the area.
• Removal of flammable liquids and gas cylinders.
• Appropriate screening, protection and display of safety notices.

[edit] Find out more

[edit] Related articles on Designing Buildings Wiki

• Fire.
• Method statement.
• Permit to work for construction.
• Risk assessment.
• Safe2Torch.
• Welding consumables.
• Welding equipment market.