Why Fire Compartmentation Must Not Be Compromised

“Fire compartmentation is an important requirement of Building Regulations’ Approved Document B with the aim of reducing the spread of fire within a building. 

Buildings are required to be sub-divided into a number of discreet compartments, using construction materials that will prevent the passage of fire from one cell to another for a given period of time.

Compartmentation is based on the premise that large fires are more dangerous to occupants, fire and rescue services and people located nearby.  Compartmentation has also been found to limit damage to a building and its contents. However, one of the main benefits of compartmentalisation is that it protects ‘means of escape’ routes from the building. This feature is particularly important where there is minimal fire separation, other than the means of escape.

Rules for Compartment walls and floors are set out in Appendix A of Approved document B2 for non-domestic buildings.  Fire resistance is expressed in terms of the number of minutes of resistance that must be provided by different parts of a building.  In the same way, doors within compartmentalised walls, and other openings, need to have a similar fire resistance to the walls or floors they inhabit.

Spaces that connect fire compartments, such as stairways and service shafts, are described as ‘protected shafts’.  These need to be protected to restrict fire spread between the compartments.

To further enhance safety, parts of a building that are occupied for different purposes should be separated from one another by compartment walls and compartment floors.

So this all seems to make sense, but the actual effectiveness of compartmentalisation depends on three things.  Firstly, was the building you are occupying built before Compartmentation became part of Building Regulations (April 2007) and is therefore not in place?  Secondly, was the fire compartmentation process carried out in accordance with the standard in the first place?  Thirdly, is the fire compartmentation inspected regularly, as part of the fire risk assessment process?

These are very serious considerations for building owners and facilities managers.  All too often, fire risk assessments are not carried out in sufficient depth, which can compromise the safety of a building.  Take, for example, the case of a school.  That school could have been built in 2008, which means that it should have safe and effective compartmentation.  However, consider what would happen if upgrades to the IT system or electrical systems have been made in that time, which means holes could have been drilled into walls and ceilings.  The integrity of the compartmentation could therefore be compromised.  No one in the school would necessarily be aware of this if in-depth fire risk assessments were not carried out regularly.  In the event of a fire, smoke and flame could spread from one compartment to another, creating a large dangerous blaze, with potentially deadly smoke inhalation, cutting off essential escape routes.

So next time your fire risk assessment is due, it is worth ensuring that your competent person or external fire inspection company actually does carry out a rigorous inspection of the effectiveness of the fire compartmentation within a building.  If you would like to find out more about protecting your building and its occupants and enhancing fire safety, or to arrange a fire inspection, please contact our team on: 01709 917555.”