Richard Sutton, general manager at Horbury Property Services, looks at fire compartmentation and how regular fire risk assessments can help to reduce dangers and prevent breaches.
3 July 2017 | Richard Sutton
In 2007 Building Regulations' Approved Document B was introduced, requiring buildings to be subdivided into a number of discrete compartments or cells using construction materials to prevent the passage of fire from one cell to another for a given period.
Compartmentation was introduced to contain fires, as large fires are more dangerous to occupants, fire and rescue services and people nearby. Fire compartmentation is also effective in limiting damage to a building and its contents and reduces the risk of fire spread.
Designed to protect 'means of escape' routes from a building, compartmentation is particularly vital where there is minimal fire separation, other than the means of escape - for example, a simple office building served by a single flight of stairs. In this case, the floor area may be open-plan, with no partitions, however, the stair should be enclosed by firewalls (and fire doors) to ensure that a fire in any part cannot pass to the stairway.
Spaces that connect fire compartments, such as stairways and service shafts, are described as 'protected shafts'. These play a vital role in restricting fire spread.
In high-rise residential blocks each flat is generally treated as its own 'cell', so fire spread from one cell to another should not occur. Depending on the size of the flat, additional fire separation is often included to protect the occupants' means of escape.
Regular in-depth fire risk assessments are essential to ensuring the integrity of fire compartmentation. Often fire risk assessments do not extend to inspecting above ceilings (or below floors) to ensure that the fire compartmentation has not been breached, but this could be an expensive mistake that severely affects fire safety.
Fire risk assessments
There are serious consequences for building owners and their FM companies that do not undertake adequate risk assessments. Fire compartmentation should be assessed and reasonable endeavours should be made to at least sample fire stopping in areas where there is potential for penetration. Smoke travels quickly - at between 15 and 90 metres a minute - and studies have shown that 67 per cent of fire-related deaths are through smoke inhalation and 44 per cent of deaths involve people who were not in the room where the fire originated.
Many public and private buildings will have seen alterations to the building fabric and layout during their lifetimes. It is therefore good practice for facilities managers to carry out a pre-works survey if any refurbishment or building services update is planned to ensure that penetrations in fire-rated construction are identified, assessed and managed.
It may be the case that there is limited data on breaches of compartmentation and plans may not truly reflect the building as it stands today. To establish the current condition of the building - specifically the compartmentation - an in-depth survey should be carried out to provide a detailed record of the location and condition of compartmentation, record penetrations, and recommend remediation works.
Take control of breaches
If installed correctly, fire separation has an enviable success rate, however, breaches through compartment walls, floors and ceilings can cause smoke, gases, and fire to spread through escape routes to other parts of the building. It also hinders the fire services' operations and can put firefighters at increased risk.
Compartmentation breaches are often down to a lack of control over external contractors carrying out works. Building owners and FMs should make sure contractors are aware of the importance of passive fire protection. Training may also need to be given to employees carrying out fire risk assessments to give sufficient knowledge in terms of the location and type of fire compartmentation, its function and the importance of maintaining them to achieve their expected level of fire resistance. Alternatively, bring in an external company to take care of assessments.
Good fire safety strategies need to be driven from the top and backed by good training to ensure that when refurbishments are carried out contractors fully understand fire compartmentation and the implications of breaching it. Failure to do this contravenes the Regulatory Reform Order (Fire Safety) 2005.