The LWF Blog

Fire Safety for Facilities Management Personnel – Structural Fire Protection – Part 158

July 12, 2022 9:43 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 157, LWF discussed fire resisting doors. In part 158, we will continue to discuss the self-closing mechanisms of fire doors.

Although a fusible link is one method of release of a self-closing fire door, it would not be suitable for doors within the escape route from the building, or which are in place to protect equipment or stock with the potential for smoke damage. The reason behind the unsuitability is that the fusible link may not operate sufficiently early to prevent the passage of large volumes of smoke.

In some types of premises, e.g. residential care homes, there may be a requirement to have all the doors within circulation spaces and doors to resident bedrooms to be held open during non-sleeping hours. These doors will all release and close when the fire alarm activates. The reasoning behind the doors being held open is for residents who have mobility issues, closed doors can be an obstruction to navigating the passageways of the building.

In some circumstances, it may be necessary to keep bedroom doors open at night too, where overnight care needs to be administered, for instance. For this purpose, free-swing devices are often installed, which permit the door to swing freely anywhere between a pre-determined position and the closed position, but which self-close on operation of the fire alarm system. Approved Document B suggests this is a suitable solution for bedroom doors in premises where self-closing doors may present an obstacle to residents.

From a building insurance point of view, the insurers usually require that fire-break doors are kept closed outside normal working hours, and that hold-open fire-resisting doors are closed at night in premises where people sleep. However, this partly originated from issues with early electro-magnetic release devices on doors which sometimes failed due to residual magnetism. Modern devices do not tend to suffer from this issue and the product standards include a test to ensure it’s not likely to happen.

If the closer and hold-open devices are in different planes of the door, then closing the door at night reduces the potential for twisting forces to warp the door and enables any potential problems of door closing to be spotted promptly.

In part 159 of this series, LWF will continue to discuss fire doors and self-closing devices. 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.