The LWF Blog
Fire Safety for Facilities Management Personnel – Means of Escape – Part 127December 6, 2021 12:39 pm
Lawrence Webster Forrest (LWF) is a specialist fire engineering and fire risk management consultancy whose aim is to give information on best practice in fire safety for facilities management personnel through this blog series. In part 126, LWF discussed means of escape and stage one and two of the three stages of escape. In part 127, we will continue looking at corridors with alternative means of escape as part of stage two of the three stages of escape.
Stage 2: Travel to a storey exit (continued from part 126)
- Corridors with alternative means of escape
Where a building contains a long corridor, it should be sub-divided by doors to separate stairways. This provision means that it is less likely both doors will be affected by smoke and other products of fire. It also limits the potential area of the corridor that could become smoke-logged. The doors used may have fire-resistance of less than 30 minutes, but should be resistant to smoke passage.
On a day-to-day basis, the doors may be held open, providing they are able to automatically close when triggered by the building’s fire alarm system or automatic smoke detectors.
BS 7273-4 provides guidance on interfacing between electrically-powered hold-open devices for doors (or door release mechanisms) and fire detection and fire alarm systems, including appropriate location, siting and spacing of the smoke detectors.
Doors as described in a long corridor are usually closed at night, but appropriate care should be taken that the sudden release of the doors cannot cause injury to occupants. Of course, particular care should be taken where the building occupants may be frail or have mobility issues, such as in a residential care facility. It might seem unlikely that a person could be injured by a door closing, but cases have been reported and in one instance, a death occurred due to injuries sustained when a care home resident was present in the doorway and the fire door was released through a central control point.
BS 7273-4 recommends warning signage is placed by such doors, the signage is commonly known as a knockdown cautionary in situations where an auditory warning is not provided.
It is important that if one exit from a long corridor is made impassable by smoke that the remaining exit capacity is sufficient for the number of occupants.
The 45 degree rule applies to the exit doors, which should preferably open in the direction of escape and must be able to open in that direction where a significant number of persons are involved. Any rooms where high risk activities are undertaken and rapid fire development could ensue must have exit doors which open outwards to allow quick evacuation from the area.
Long corridors should have wall and ceiling linings with low flammability and escape routes must never be obstructed in width or contain fire hazards. This means no occasional furniture or planters.
In part 128 of this series, LWF will look at the requirements for dead-end corridors. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact LWF on freephone 0800 410 1130.
Lawrence Webster Forrest is a fire engineering consultancy based in Surrey with over 25 years’ experience, which provides a wide range of consultancy services to professionals involved in the design, development and construction and operation of buildings.
While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.