The LWF Blog

Fire Safety for Facilities Management Personnel – Smoke Spread – Part 257

June 17, 2024 10:55 am

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 256, LWF talked about smoke control and the effects of smoke on business continuity. In part 257, we begin to look at the spread of smoke.

In the early stages of a fire, even before flames would be visible to the naked eye, smoke will begin to spread beyond the room of fire origin, likely due to an open door. As the fire develops, pressures are created by expanding gases and smoke will begin to permeate any small gaps, and so the fit of closed doors in their frames becomes important. Smoke will move through gaps because of the pressure differential created across the door.

Smoke will move through unstopped service penetrations in the walls, ceiling and floors too. These could be pipework or cabling which has not been adequately fire-stopped at the time of installation, or maintained subsequently.

Once smoke has spread outside of the room of fire origin, it may continue largely unimpeded along corridors, stairways, service ducts etc. causing a large part of the building to become smoke logged. The only way to avoid this scenario is for the construction of the building to be adequately fire-stopped and/or the use of smoke management systems.

There are various ways to help to control the spread of fire, some are simple and straightforward and may be seen in most buildings as a basic design feature. Others are more sophisticated. Whatever methods of smoke control are employed in a building, their purpose, mode of operation and requirements for maintenance must be understood by whomever is responsible for the building and its maintenance.

The type of smoke control measure employed are likely to depend on the objectives decided upon:

• Protecting means of escape
• Assisting the Fire Service in their duties
• Limiting damage to the building and contents

Smoke control can be considered effective if it achieves one of two methods – that the smoke is contained in the area of fire origin, or that it is ventilated from the building. The measures of smoke control may be fundamental (incorporated into most building designs) or special (more sophisticated and necessary for certain applications).

In part 258 of this series, LWF will continue to discuss smoke containment by physical barriers.  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 35 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.