The LWF Blog

Fire Safety for Facilities Management Personnel – Means of Escape – Part 130

January 4, 2022 1:13 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 129, LWF began to look at Stage 3, which is vertical travel down a stairway. In part 30, we continue discussing Stage 3 of the three stages of escape.

Stage 3: Vertical travel down a stairway (continued)

In a building which only has one stairway between floors, an effective ‘dead-end’ is created and therefore travel distance limitations effectively restrict the potential floor area. Additionally, codes of practice can restrict the height and number of storeys of a building served by only one stairway.

Usually, protected lobbies are provided in such buildings between the single stairway and the accommodation on each floor. This is to avoid the passage of smoke from the accommodation to the stairway with the purpose of prolonging sustainable conditions in the escape route. The same effect can also be achieved by use of a protected corridor leading to the stairway.

The capacity of the stairway must be sufficient for the number of occupants in the building. In buildings with two or more stairways, it should be sufficient even when one stairway is discounted in case it cannot be used due to the fire. It is not always necessary to discount one stairway, but each situation must be assessed on its own merits.

The route to an alternative escape route should not have to pass through a stairway enclosure (unless that forms part of the escape route). Equally, the only route from one area of the building to another should not be through the stairway enclosure. The use of the area as a main thoroughfare to access other areas of the building will increase wear on the stairway doors and may mean that building occupants prop the doors open for ease of access, which would negate the purpose of the enclosure in a fire situation. The only likely exception for this is where automatic door-release units hold the doors open on a day to day basis and operate when a fire is detected, however, this should be avoided where possible.

Where viable, a stairway should lead to a final exit. Where this is not possible, two exits should be accessible from the stairway enclosure, each leading to final exits via routes that are fire-separated from each other with fire-resisting construction. There may simply be a protected route to a final exit.

Additionally, if there is more than one stairway without final exits from within the protected enclosures of the stairways, the routes from each stairway should be fire-separated.

In part 131 of this series, LWF will continue discussing Stage 3 – Vertical travel down a stairway. 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.