Keeping it in the box - Fire compartmentation

A common focus in our training and consultancy on fire safety is compartmentation, particularly so when carrying out fire risk assessments and providing guidance and recommended actions to responsible persons. To counter a popular phrase, this is one scenario where you do not want to be thinking outside of the box – and for good reason, as breaks in compartmentation can often lead to the rapid development of a fire through the spread of heat and/or smoke.

According to UK government statistics, 12,939 fires were recorded on work premises in 2021/2022. Fires confined to a small area are easier for businesses to recover from and therefore have a reduced impact on business continuity.

What is fire compartmentation?

Under the Building Regulations 2010 Approved Document B Volumes 1 and 2, a compartment is defined as:

“A building or part of a building, comprising one or more rooms, spaces or storeys, that is constructed to prevent the spread of fire to or from another part of the same building or an adjoining building.”

What is the purpose of fire compartmentation?

Essentially, compartmentation is required for life safety and property protection purposes. Effective compartmentation contains the fire to a respectfully smaller area than if it were given the opportunity to spread, and therefore also reduces the likelihood of it developing as the amount of combustible material is also restricted.

It also provides an element of time that is incredibly valuable to both the occupants to safely and effectively evacuate the building, but also for the fire and rescue service to arrive and take a controlled approach to effectively fight the fire.

By its nature, effective compartmentation will:

• Prevent the rapid spread of fire, heat and smoke
• Subdivide buildings into manageable areas of risk
• Provide and protect adequate means of escape
• Maintain provisions in statutory guidance documents
• Control fire size by managing the amount of fuel available

What are some examples of fire compartmentation?

Fire compartmentation is a form of passive fire protection – this is something that slows or impedes the spread of the effects of fire or smoke without system activation, and usually without movement. Common examples include, but are not limited to:

• Floors and ceilings
• Walls

Special measures to address openings for:

• Fire doors
• Windows
• Glazing
• Ductwork
• Service penetrations
• Cavities

Elements of compartmentation commonly offer between 30 and 120 minutes of fire resistance, depending on the premises and setting. The wall or floor must remain functional for the duration of the designed fire resistance period and it is essential that any component is suitably selected, installed and maintained by competent persons.

Any weakness in an element of compartmentation can be exploited and result in serious consequences.

Common failings in fire compartmentation

Common failings in the condition and/or effectiveness of fire compartmentation include, but are not limited to:

• Fire doors

Incorrectly installed, missing intumescent strips, damage to the door, missing or incorrect fixtures and fittings, non-fire-rated accessories including letter boxes and glazing

• Ceiling tiles

Missing tiles allowing heat, flame and smoke to transfer, non-fire-rated tiles that can ignite, fire-stopping of walls does not continue to the roof

• Services

Holes created in walls and floors are not correctly sealed, collars not fitted around pipework, non-fire-rated materials used, dampers not maintained

• Human behaviours

Blocking fire doors, using door wedges on fire doors, damage to materials through neglect or misuse, lack of reporting on damage

Further advice and guidance

A requirement under the Regulatory Reform (Fire Safety) Order 2005 is to have a suitable and sufficient fire risk assessment in place, carried out by a competent person. Whilst it is good practice to complete an internal review of the assessment annually, it is considered best practice to have an external review every three to five years, depending on the complexity and risk of operations at the premises.

The British Woodworking Federation Fire Door Alliance is a nationally recognised scheme promoting the importance of fire door safety, hosting the Fire Door Safety Week event each year (normally in September). They produce a range of valuable resources, available here: https://firedoors.bwf.org.uk/

Further support and advice on this topic is available from our range of training and consultancy services.

Dave Wright GradIOSH AIFireE

June 2023