What Is Compartmentation?

Fire safety extends far beyond fire alarms and extinguishers. The way a building is designed and constructed can play an equally important role in protecting the people inside it.

Fire compartmentation is a fundamental part of passive fire protection. It involves dividing a building into fire-resistant compartments designed to restrict the spread of fire and smoke for a specified period. But what is compartmentation in practice, and why is compartmentation in fire safety so important?

In this blog, we’ll explore this in more detail, along with explaining how fire compartmentation works, the different measures involved, and the regulations in place that surround the practice.

Key takeaways

• Fire compartmentation divides a building into fire-resistant areas designed to restrict the spread of fire and smoke.
• Compartmentation is a fundamental part of passive fire protection and helps provide occupants with more time to evacuate safely.
• Fire-resistant walls, floors, fire doors, cavity barriers, dampers, and correctly installed fire stopping can all contribute to maintaining a building’s compartments.
• Compartmentation should be properly maintained throughout the life of the building, particularly following alterations or the installation of new services.
• Fire resistance and compartmentation regulations, like Approved Document B, for a building will depend on factors including its use, construction, height, and applicable fire safety guidance.

What is compartmentation?

In simple terms, fire compartmentation is the practice of dividing a building into separate areas that are designed to resist the spread of fire and smoke.

Each compartment creates a degree of separation from other areas of the building. If a fire starts within one compartment, the surrounding fire-resistant construction is intended to restrict its spread for a specified period. This can provide occupants with valuable additional time to evacuate and allow the fire and rescue service to respond.

Effective compartmentation relies on the different elements of the building working together. Fire resistant walls and floors can form the boundaries of a compartment, while measures such as fire doors, cavity barriers, and correctly installed fire stopping help maintain those boundaries where openings or building services are present.

Fire compartmentation can be incorporated into both residential and non-residential buildings, and forms an important element of a wider passive fire protection strategy.

What are the different types of fire compartmentation measures?

There is no single product that creates effective compartmentation. Instead, a number of passive fire protection measures can work together to restrict the movement of fire and smoke through a building.

These can include:

• Fire-resistant walls and floors – designed to provide separation between different areas of the building for an appropriate period of fire resistance.
• Fire doors – installed within openings in compartment walls to maintain the required level of fire separation while still allowing people to move through the building.
• Fire stopping – used to reinstate the fire resistance of walls and floors where they’ve been penetrated by services such as cables, pipes, and ducts.
• Cavity barriers – positioned within concealed cavities to restrict the unseen spread of fire and smoke.
• Fire and smoke dampers – used with ventilation and ductwork systems where required to help maintain compartmentation.

These measures shouldn’t be considered in isolation. A compartment is only as effective as the elements that form and penetrate its boundaries. Damage, inappropriate alterations, or poorly installed services can create weaknesses that allow fire and smoke to move into adjoining areas.

Understanding where compartmentation measures are located within a building is therefore an important part of maintaining effective fire safety.

Why is fire compartmentation important for fire safety?

The primary purpose of fire compartmentation is to restrict fire and smoke to a defined part of a building rather than allowing them to spread rapidly into surrounding areas. This is particularly important for life safety.

Containing a fire can help maintain escape routes for longer and provide occupants with additional time to move away from danger and evacuate the building. It can also help prevent smoke and flames from spreading into other occupied areas before an evacuation has taken place.

Effective compartmentation can also give the fire and rescue service more time to respond and possibly help restrict the extent of damage to the building.

There can be significant benefits for property protection and business continuity too. Important infrastructure, equipment, and higher-risk areas may be separated from other parts of a building to reduce the likelihood of a fire affecting the entire premises.

This is why compartmentation in fire safety should be viewed as an ongoing part of protecting people and buildings, rather than simply a feature installed during construction.

How is fire compartmentation maintained?

Fire compartmentation needs to remain effective throughout the life of a building.

A building that was correctly compartmented when it was constructed can develop weaknesses as it’s altered, refurbished, or maintained. New pipework, electrical cables, ventilation systems, and other services may pass through compartment walls and floors, which create openings that need to be appropriately fire stopped.

There are also other issues that need to be considered, including:

• Damaged fire stopping
• Deterioration to fire-resistant construction
• Incorrectly fitted materials
• Defects to fire doors

This makes ongoing inspections particularly important. A fire compartmentation survey can assess the condition of compartment lines and identify breaches or defects that could affect their ability to restrict the spread of fire and smoke.

Where remedial work is required, it should be carried out using suitable systems and methods appropriate to the building and the required level of fire resistance.

Maintaining compartmentation isn’t simply about repairing visible damage. It means considering the effect that ongoing building works can have on your passive fire protection strategy and ensuring those protective measures remain effective over time.

What are the current UK fire compartmentation regulations?

For buildings in England, fire compartmentation regulations – specifically in relation to building design – are outlined in Approved Document B. This legislation applies to both residential and non-residential buildings, and there are a variety of details that pertain to fire safety in and around buildings. 

Some of the key points that need to be considered for compartmentation include:

• Minimum periods of fire resistance – this can apply to a variety of elements within the structure, including walls and floors, with the presence (or lack) of a sprinkler system having an impact on the minimum resistance levels required.
• Building heights – if your building is over 30m in height, then there needs to be a compliant compartmentation floor in between every storey of the building.
• Common walls – if a wall is common to two or more other buildings, then it should be built as a compartmentation wall.
• Permitted openings – where adjoined buildings share a compartment wall, it should only be disrupted by fire doors or pipework that has been fire stopped by a professional company, like Fire Industry Specialists (FIS).
• Beams and joists – where any compartment is connected via a beam or joist, this also needs to be fire stopped to ensure flames and smoke can’t spread through openings.
• Cavity barriers and fire-resistant ceilings – where either of these components are installed in a building, they should be able to withstand fire for 30 minutes at a minimum.

It’s important to note that Approved Document B applies to buildings located in England. Different building regulations and guidance may apply elsewhere in the UK, so the relevant requirements for your specific building location should be considered.

Adhering to these fire compartmentation regulations means not only are you taking fire safety within your building seriously, but you’re also prioritising the safety and well-being of occupants.

Speak to us about fire compartmentation in your building

It’s clear to see that effective compartmentation is a fundamental part of protecting people, property, and escape routes in the event of a fire. It’s important to speak to professional fire safety specialists to ensure your fire stopping measures are installed and maintained according to fire compartmentation regulations for peace of mind.

At FIS, we provide a range of professional passive fire protection services to help businesses establish and maintain effective compartmentation, including fire stopping, fire doors, and fire barriers.

Our team of qualified engineers and consultants work with organisations across Lincoln, Nottingham, Manchester, Birmingham, Sheffield, and the wider UK to identify fire safety requirements, assess existing passive fire protection measures, and complete appropriate remedial work.

If you have any concerns about the compartmentation within your building or need support assessing existing fire stopping measures, don’t hesitate to contact our team today to discuss your requirements in more detail.