Compartmentation |Blocks of flats

Compartmentation within blocks of flats refers to each flat being contained within fire resisting construction, designed to withstand fire. The walls and floor of each ‘compartment’ are designed to resist fire for a sufficiently long period, so that the fire would burn itself out before those fire resistant walls and floor would allow fire spread to other parts of the building.

It is an essential part of the fire safety strategy for blocks of flats for many reasons, chief amongst them, of course, are life preservation, building integrity and damage limitation.

Effective compartmentation helps to ensure that fire cannot spread from the point of fire origin (within the compartmented flat) to common areas such as landings, staircases and communal rooms. It also considers ‘hidden’ areas of potential fire spread such as concealed voids, external wall cavities, ducts and service risers and will take into account shafts such as rubbish chutes, lift shafts etc.

It would be usual practice for each flat or dwelling to be one compartment. This means, in essence, that fire can spread within that one flat, but should not pass from that flat to another, or to a common area.

However, even with fire resistant walls, ceiling and floor, there are many areas which should be considered to avoid fire spread.

The front door of each flat should be a fire door, which means it is fire resistant and self-closing, but doors inside each flat do not need to be fire doors. All other doors within common areas, entrances to staircases etc. should also be fire doors.

Internal windows which look onto corridors and any windowed area around or within the entrance door to the flat must be fire resistant. Openings in walls, such as those made for services like gas, electricity, water and telecommunications must be considered and the risk mitigated with fire resistant construction.

Shared vents can also be an issue. It can be common to have shared extract ducts from bathrooms and kitchens which may be an escape route for a fire. Equally, openings that are in walls for the purposes of communal heating systems and hot water supply can be a risk.

Of course, fire spread is not the only issue. Smoke spreading from one compartment to another can cause risk to life safety and make safe evacuation impossible.

Regular fire risk assessments and tenant awareness campaigns are an essential part of ensuring the continued impenetrability of the compartmentation. Commonly, contractors and tenants are unaware of the nature of compartmentation in floors and walls and will simply drill through to feed cables for satellite dishes, for example.

Only a well constructed and maintained compartmentation of a block can ensure the safety of the tenants and allow the use of the ‘stay put’ policy of evacuation, in the case of fire.

What may seem like simple changes to the block may impact upon the fire safety of the block and the lives of those within it. The inquest into the fatal Lakanal block fire in 2009, which claimed the lives of six residents, concluded that the fire had spread so fast due to ‘botched’ improvements including the replacement of asbestos cladding on the outside face of the block with one that was not fire resistant. An adequate fire risk assessment had not taken place and the disaster was simply waiting to happen. 

Complete Fire Safety Management is the only fully comprehensive online fire risk assessment, fire safety training and fire procedures system available to individual or multi-site businesses. If you would like more information, or feel that you have particular needs which should be addressed by a fire engineer, please contact Peter Gyere on 020 8668 866.