The LWF Blog

Passive fire protection for Building Professionals – Part 11

April 2, 2020 7:34 am

In LWFs blog series on passive fire protection for building professionals and contractors and those with an interest in structural fire protection issues, we aim to give an overview of the important role passive protection plays in the overall fire safety provision of a building. In part 10, LWF looked at fire door components and in part 11, we will continue discussing fire door components, in particular, hinges and locks.

BS 1935 standard hinges should be used when fitting a fire door from new (https://shop.bsigroup.com/en/ProductDetail/?pid=000000000030118674). These hinges can be packed with an intumescent hinge pad which prevents the passage of heat beyond the hinge plate for a fixed period of time. This safeguard helps to ensure that the inside face of the door doesn’t become charred by the conduction of heat through the hinge and screws.

It is important that the hinges chosen to use with a fire door are appropriate for the purpose. If the hinge does not have structural integrity for at least the same fire protection period as the door, the failure of the hinge will result in the early failure of the door in a fire situation. Fire doors with lesser hinges have been known to simply fall out of their frames during a fire.

While 30-minute fire doors are not always fitted with intumescent hinge pads, 60-minute timber fire doors invariably are and this enables them to withstand the 60-minute fire door test and the resulting additional temperatures.

In the case of historic doors, the view may be that a part of the listed door is the use of a historic hinge. Such hinges are often constructed from iron or similar materials and are substantial. A suitably-trained professional will be able to ascertain if the hinges on historic fire doors are upgradable and if the level of protection offered befits the risk level of the building. However, each situation should be considered on its own merits and it is not possible to present a definitive generic answer.

A further component that may be seen in a fire door is a lock. The fabric of a lock can contribute significantly to heat transfer into the door. When a fire occurs, it will thermally degrade the door and break it down as heat is conducted into the centre of the door.

In part 12 of this series, LWF will continue to look at fire door components and in particular, locks used in fire doors. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact LWF on free phone 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.