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Impending changes to fire regulations mean that the fire risk of many buildings will come under increased scrutiny. Here Andrew Forecast discusses the impact on the specification of fire-rated doorsets.
There are still five months to go before the Regulatory Reform Fire Safety Order (RRFSO) comes into force on 1 October, but it seems as though every man and his dog have been weighing up its pros and cons! Although regular readers of fire engineering journals have heard this before, its popularity as a topic does emphasise the influence that this fundamental change in the fire regulations is having on the building industry, and the effect it is going to have on the building owner/employer.
While there seem to be kinks in the full understanding of the role of the ‘responsible person’ – or indeed the ‘competent person’ – who feature so largely in the new legislation, it is generally accepted that the fire risk in our nation’s commercial property portfolio is to be called in for questioning.
With this in mind, a simple first step for those anxious to ensure their house is in order is to assess the current condition of the passive controls in place in the working environment. There has been a huge increase in interest in the use and maintenance of fire-resisting doorsets and, reading between the lines, this is because fire doors are the acknowledged first line of passive defence against the passage of fire and smoke through a building.
A fire-resisting doorset is designed to function both as a door and, critically, as a barrier to a fully developed fire in a building. Although any closed door will have some delaying effect on the development and spread of a fire, a fire door must be proven to be capable of resisting the effects of a standard fire test for stipulated periods, usually 20, 30 or 60 minutes.
Understandably, the requirements for fire doors are complex. While representative examples of intended fire door designs are required to be tested to BS 476-22: 1987 Methods for determination of the fire resistance of non-load bearing elements of construction, or to BS EN 1634 – 1: 2000 Fire resistance tests for door and shutter assemblies, this is rarely – if ever – feasible for doorsets upgraded in situ. In most cases, regulatory authorities are willing to accept an assessment of likely performance in lieu of a test result.
It is often preferable – and safer – to install new and third-party certified doors when refurbishing or upgrading the passive fire protection of existing buildings. That said, there are circumstances where it is necessary to retain the existing door, for example, to comply with fire regulations when the use of the building has changed. Upgrading might also be considered to meet either retroactive legislation or new insurance requirements.
In such cases, existing doorsets may be upgraded to achieve the required fire resisting performance. But it is vital to look at each case individually, as existing doorset installations and the condition of the leaves and the frame will vary from building to building. Given this, it is recommended that existing doorsets are independently surveyed by an expert, where either enhanced fire resistance is required or general confirmation of their performance is needed.
What of new fire-rated doorsets? The question of fitting a new one will arise when there is a change in compartment lines, or because the existing doorset is inadequate for upgrade. But it is not quite as easy as buying any standard leaf and frame and blindly fitting them into the prepared opening. These types of performance products are not just a piece of wood in a hole, and they will only provide the desired integrity if installed in accordance with the requirements of the test/assessment data. Consequently, it shouldn’t be assumed that all fire-resisting doorsets can be used in all situations.
There have been cases where installed doorsets have been rejected – quite simply because the main construction of the structural surround is incompatible with the doorset – and this will vary from one manufacturer to another.
When specifying a new doorset for installation, the main structural surrounds must be taken into consideration, as an incorrect assumption will cause hefty and unacceptable time delays to the client. Equally, installers and specifiers are faced with similar pitfalls if they assume that any door frame can be married up with any door blank.
So how would one police this to ensure that the beautiful, new, expensive door leaning against the staircase ready for installation will be acceptable? The answer to this is not new by any stretch of the imagination, but is one that has increasing weight in the specifying industry – third-party certification. Schemes such as BM TRADA’s Q-Mark for fire doors ensure not only that the products themselves are manufactured to a consistently high standard time after time, but also that all installation details of either the doorset (frame and leaf etc), or the additional components required to complete the doorset, are passed directly onto the specifier or installer.
It is not necessarily always appropriate to use ‘standard’ doorset details. Doorsets form a large, visible part of our internal (and external) built environment. Consequently, bespoke designs and elevations can not only encourage our enthusiasm for the place in which we work, but also fire our appreciation for good design.
It is essential, however, that bespoke constructions are technically assessed using project-specific assessment reports. These should be based on primary test data, which will (when appropriate) provide cover for architecturally pleasing doorset creations. These reports spell out the required construction and installation methods for the proposed design to achieve the desired integrity performance. While these types of constructions should not be justified by anyone other than a technically competent fire engineer, one should not necessarily allow free thinking to be bound by factory standard details.
There is no doubt that the RRFSO has started people thinking of fire safety within buildings, and has indeed brought to the fore the importance of constructions such as fire-rated doorsets. It is essential, however, not to make untrained assumptions of existing doorset integrity performances. Nor should anyone lose sight of the fact that the primary function of a fire door is to stop the spread of fire, thus ensuring that a building measures up to the new regulations according to its perceived fire risk.
Andrew Forecast is an engineer with Chiltern International Fire and can be contacted on 01494 569811 or email aforecast@chilternfire.co.uk. For information on BM TRADA Q-Mark visit www.bmtrada.com.