The LWF Blog

Passive fire protection for Building Professionals – Part 12

April 9, 2020 8:22 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 11, LWF looked at fire door components and in particular, hinges and locks. In part 12, we will continue discussing the locks used in fire door assemblies.

When a fire door is exposed to the heat of a fire, the effect of a fire can conduct heat into the centre of the door, the material of the lock contributes to the heat transfer into the door. The persistent conducted heat will degrade the core of the door and will result in the passage of heat through the door, charring it internally and compromising its integrity.

During fire testing, fire door failure through conducted heat is a relatively common cause of failure. One way of avoiding excessive heat transfer through the lock is for intumescent pads to be fitted to the lock. This can potentially remedy the heat transfer issue in a fire door, with otherwise suitable performance but in itself is not a guarantee of adequate performance.

Only locks which have been fire tested with the door in question should be fitted. In cases where locks are already in place, a competent professional can potentially make an assessment of adequacy, however, without fire test data, the assessment will be little more than an educated guess.

It is important to use an adequately trained and competent fire safety professional when undertaking fire door surveys. Fire door surveys are generally performed by fire door surveyors who have completed a one-day course in the subject. Such courses teach the surveyor how to inspect a fire door and pass or fail it. This is dependent on whether appropriate components are installed. It often does not address the issue of whether fire doors and components have been tested together in a fire situation and may not even address whether the type and use of door, the weight and construction are suitable for the purpose to which they are put.

A competent fire door inspector should have received appropriate training and will be able to use their professional judgement on any existing fire door and make recommendations for upgrading. Unfortunately, fire door inspector training is often only a one day course. As such professional competence is often a rare commodity. It is always best to see an example of their CV and previous work so that you can be assured that the fire door inspector is competent and, more importantly that you can read and understand any reports produced. Quite often the outcome of a fire door inspectors report is one that favours the author and not the recipient. These reports may be complex and less than useful using codes to describe deficiencies rather than plain language.

In part 13 of this series, LWF will continue looking at the components used in fire doors, beginning with letterboxes. 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.