In order to provide complete functionality, this web site needs your explicit consent to store browser cookies. If you don't allow cookies, you may not be able to use certain features of the web site including but not limited to: log in, buy products, see personalized content, switch between site cultures. It is recommended that you allow all cookies.

Site Search

Compartmentation

Compartmentation is an important part of the passive system within the overall fire safety system of a building.  The fire safety system of a building must be suited to the function of a building;  the activities carried out in that building and the number, nature and physical abilities of the people who occupy or use the building.  The three main components of a fire safety system comprise passive safety, active safety and management systems. 

Compartmentation in passive systems

The passive systems include fire separation and compartmentation through fire doors, which may also be smoke-rated to control the spread of smoke, partitioning and materials such as concrete etc.  Active  systems include fire alarms, wet and dry risers,  smoke control through ventilation and sprinklers.

Management systems include the risk assessment, audit, rehearsal, review, maintenance and communication and liaison. 

All three of these systems should be integrated and interdependent.

Fire resisting partitions and fire doors which form the compartmentation of a building play a critical safety role and the correct type of product should be specified.  Furthermore, it should be properly installed – by competent persons able to fully understand the importance of correct installation of the product in the context of fire safety.

Approved Document B of the building regulations stipulates the functional requirements of fire safety as follows:

B1 – Satisfactory provision of means of alarm and satisfactory means of escape

B2 – Inhibit spread of fire over internal linings

B3 – Ensure stability of building and fire separation within buildings and between adjoining buildings for an appropriate period

B4 – External walls and roof resistance to spread of fire over (building) envelope and to adjoining buildings

B5 – Access for fire appliances and facilities to assist fire fighters

For the high rise safety model there are assumptions in Building Regulations:

  • The fire will [usually] originate in a flat or maisonette

  • No reliance on external rescue by ladder etc

  • Provide a high degree of compartmentation to ensure low probability of spread beyond flat / maisonette of origin

  • Although fire may start in common parts of a building, high levels of fire resistance will prevent spread.

BS5588 pt 1 states: “Owing to the high degree of compartmentation provided in blocks of flats and/ or maisonettes, the spread of fire from one dwelling to another is unusual.  It is, therefore, no longer assumed that – in the event of fire – it is necessary to evacuate the whole building, whole floors or even dwellings adjacent to the fire”

Compartmentation in design

It is a long and established principle that the design and construction of high rise buildings enables the occupants adjacent to the immediate fire area to be able to make their way to a place of safety, while other occupants can remain safely within their homes.  However, this principle does require that a satisfactory level of passive and active fire safety systems are installed and maintained.

Fire safety provision will have been incorporated into a building when it was designed and built, but with an older building, standards may have become more demanding.  There may have been changes in a building’s layout or the nature and number of occupants may warrant a re-examination of the fire safety systems.

In specifying the fire resistance of compartments we consider three possible modes of failure of the partitions which comprise:

(1) ceiling above

(2) floor below

(3) walls/doors which form the compartment

When exposed to fire will they maintain:

  • Stability (ie not collapse);

  • Integrity (ie not be holed, cracked, or otherwise perforated);

  • Fire stopping (ie prevent the passage of fire by conduction, convection or radiation).

The ability of a compartment to maintain these features giving effective compartmentation is measured in minutes.

It is essential that for the component parts to work as they should in compartmentation, ie fire doors, then they must perform to the specified time required – given their location in a building and the building structure. 

For example in a stairwell area which is a protected shaft – the compartmentation required will be 60 to 120 minutes dependent on the partition type.  If this is a fire door, then it needs to have performed to the recognised standard BS476 pt 22 1987 or EN1634-1 in a fire test where they are typically exposed to live fire on one face at temperatures approaching 950°C while the temperature and the passage of smoke on the unexposed face is closely monitored for 60 minutes.

As a compartmented area forms part of a fire fighting area, then damaged or inadequate compartmentation  could  hinder or affect the fire service response and in the worst instance give rise to serious risks for fire fighters.  This could result in enforcement action being taken against the Responsible Person under Article 38 of the RR(FS)O – ‘Maintenance of measures provided for protection of fire fighters.’

Therefore it is essential that the compartmentation of a building is the right type of compartmentation and is maintained “[..] in an efficient state, in efficient  working order and in good repair.” (Article 38-(1).

Please click here for Communal Fire Doorsets