Everything you need to know about fire compartmentation

Effective compartmentation is integral to any passive fire protection strategy. It should be incorporated into a construction project as early as possible to help ensure buildings remain structurally sound in the event of a fire. Compartmentation is also crucial for compliance with fire protection regulations and industry standards. This article will introduce you to the main principles of compartmentation, as well as some of the rules and requirements that help establish best practice.

What is compartmentation?

Putting it simply, compartmentation is the process of dividing a structure into ‘compartments’ for effective risk management. Each compartment is reinforced either by using fire-resistant materials or by installing measures such as fire doors or cavity barriers.

What is the main objective of fire compartmentation?

The main objective of compartmentation is to contain a fire within a specific section of a building, limiting the passage of flames and smoke. This then allows more time for occupants to safely evacuate a building and for fire services to extinguish the flames.

Whilst safety is always of paramount importance, another common objective of fire compartmentation is to prevent a fire from reaching parts of a building that are of particular value, or contain hazardous materials. Common examples include modular plant rooms in industrial buildings or server rooms in commercial premises.

Fire evacuation procedures can vary based on a building’s purpose, size and any specific risks. For instance, buildings may utilise a ‘defend in place’ strategy, which looks to minimise the number of people required to evacuate a building. This strategy is often used in healthcare facilities, where staff may find it virtually impossible to evacuate highly vulnerable patients.

CLM Fireproofing has provided fully-compliant compartmentation for construction projects across the UK. A great example of this is One Crown Place, an exciting Hackney-based construction project. Take a look at our case study to find out more and contact CLM Fireproofing if you have any questions.

Managing risks in compartmentation

Like any fire protection system, compartment walls and floors must be regularly monitored and maintained if they are to remain effective. There are several specific risks that must be quickly identified and managed so that buildings are as secure as possible in the event of a fire.

Construction projects will always involve third-party installers such as electricians and plumbers. These installers may inadvertently cause breaches in fire compartments when fitting wires, pipes or other similar elements. The smallest breach can compromise the integrity of a compartment. Therefore, it is paramount that any breaches are identified and rectified using appropriate fire stopping methods.

Fire doors can also be considered part of a compartmentation strategy. However, they are often subject to either misuse or neglect. One of the most common examples is fire doors being wedged open to ensure easy access. This can cause what is referred to as the ‘chimney effect’, which is when the spread of fire is exacerbated by air moving in and out of a building. It was estimated in 2018 that 64% of buildings visited by fire services had a fire door wedged open. Therefore, while a building’s occupants must be warned about the risks associated with misuse, property owners and commercial landlords must invest in regular fire door inspections and maintenance.

Fire compartmentation requirements

The most relevant and up-to-date compartmentation regulations can be found in Approved Document B. This document covers all regulatory matters relating to fire safety in and around buildings. To give you an indication of what the document covers in relation to compartmentation (in non-residential buildings), we’ve listed some of the main points below.

• The minimum period of fire resistance for a compartment wall or floor can vary based on a building’s specific purpose as well as the presence of sprinkler systems. A comprehensive overview of minimum fire resistance periods can be found here.
• When a building is over 30m in height, each storey must be separated by a fully-compliant compartment floor.
• Any wall that is common to two or more buildings should be constructed as a compartment wall. These should extend to the full height of a building in a ‘continuous vertical plane.’
• Compartment walls should ideally be used to separate areas of a building that serve different purposes (e.g. storage or commercial operations).
• If a compartment wall is installed between two adjoining buildings, the only permitted openings are for fully-compliant fire doors and pipes. It is imperative that these pipes are appropriately firestopped, regardless of their diameter.
• While compartments should ideally be completely separated, there may be instances where they are connected by beams, joists or rafters. If so, any openings caused by these structural elements must be appropriately firestopped.
• Construction teams may look to install fire-resistant ceilings and cavity barriers as part of a compartmentation strategy. If so, these must be able to hold their structural integrity for a minimum of 30 minutes in the event of a fire.

CLM Fireproofing is the UK’s leading provider of passive fire protection services, including compartmentation. Working with clients across many different industries, we ensure that buildings (both residential and non-residential) are fully compliant with the latest fire protection regulations. If you’d like to know more about our services, please contact us today.