The LWF Blog

Fire Safety for Facilities Management Personnel – Means of Escape – Part 129

December 20, 2021 12:40 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 128, LWF looked at the requirements for dead-end corridors, as part of stage two of the three stages of escape. In part 129, we begin to look at Stage 3, which is vertical travel down a stairway.

Stage 3: Vertical travel down a stairway

When assessing means of escape, there are certain elements that should be borne in mind involving stairways.

Limitations on travel distance are measured to the stair / lobby entry point if the stairway is protected. A protected stairway is, in itself, a fire-resistant compartment and therefore, providing the doors to the stairway are self-closing and fire-resisting (and well fitted in their frames to protect against smoke penetration) the travel distance limits can be set aside for this area.

Doors to stairways are permitted to have automatic hold open units fitted that allow the doors to be held open on a normal basis, but which are closed automatically when the fire alarm system detects a fire.

BS 7273 is the Code of Practice which covers the interface of automatic hold-open devices with the fire alarm and detection system. The use of automatic hold-open devices was not permitted in the past but with the provision of the code of practice and the acceptance that such systems were preferable to the manual wedging open of doors often seen, their use became accepted by the enforcing authorities.

It should be noted however, that while the guidance in England and Wales allows the use of door-release units without restriction, there are conditions that must be met in other areas. Regulations in Scotland limit their use in that they are not to be used on stairway doors in buildings, or parts of buildings, where there is only one protected stairway for escape. This applies to buildings where people sleep and in the case of fire-fighting stairways.

In Northern Ireland, the use of electrically powered hold-open devices is restricted on doors to fire-fighting stairways.

An unprotected stairway – i.e. it is not enclosed in fire-resistant construction – offers no protection from fire or smoke and therefore if it forms a part of the means of escape, the distance travelled on the staircase should be included in the travel distance calculation for Stage 2 of means of escape.

In some premises, an unprotected stairway is not acceptable at all. Even when it does not form part of the means of escape from a building, it can be a means for fire to spread from one storey to the next. Restrictions on unprotected stairways should be investigated for each project and building on an individual basis.

In part 130 of this series, LWF will continue looking at Stage 3 of the three stages of escape. 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.