Fire stopping – the danger of installer incompetence

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There are cowboy electrical contractors just as there are cowboy car mechanics, but at least in the motor trade, product suppliers provide clear and detailed warnings about tampering with a car’s safety. Using the example of downlighters Peter Jackman explains how incompetence in the fire safety industry is an even more frightening prospect.

It is inconceivable that a car mechanic would fit a car sound system that required the anchorage provided for the seat-belt restraint to be compromised, or which interfered with the operation of the air bags. The mechanic would be very aware that, should there ever be an accident involving the car in question, especially if there were to be injury or death to the occupants, he would be culpable.

At best, when the car comes up for its annual MOT the defect would be discovered and the vehicle owner would fail to be awarded a certificate. The car would soon be returned to the mechanic in question for the reinstatement of the safety measures or compensation. In fact, it is unlikely that a car accessory that could compromise safety to this extent could even be sold openly to the public through the retail motor trade.

Unfortunately, in the construction industry, it is conceivable for a tradesman to compromise the fire safety of a building. So how is it that such a discrepancy can occur between the two industries. The reasons include:

– the education and training that a car mechanic receives compared to some construction tradesmen;

– the instant recognition of the safety measures that are provided in a vehicle as a result of labelling and/or publicity;

– in-built measures in a car that increase the tamper resistance of the safety features, sometimes requiring special tools;

– the provision of a detailed manual with every new vehicle; and

– the annual safety check (MOT), which has to be undertaken if the vehicle is to remain in service.

Most of the above exist in the automotive field, but this is not necessarily the case in the construction industry. Let us consider the situation of an electrician fitting concealed downlighters into the ceiling of a third floor luxury apartment. In terms of specific training, there may not be much difference. But assuming a reputable electrician is used – there are cowboy car mechanics just as there are cowboy electricians – the breadth of training might show significant differences. One would feel confident that the electrician would be adequately trained to provide an ‘electrically safe’ installation, but compared to the motor mechanic, whose training would invariably encompass the important safety features in a vehicle, there is a serious risk that the electrician would not be aware of the other safety features in the building.

The lack of awareness of these safety features may result from the second point – labelling and publicity. Despite the perceived ‘invasion’ that labels may produce in respect of the aesthetics, seat belts and air bags normally carry warning and advisory labels. These labels impart to the user and mechanic alike the important features of the installation. In fire safety terms especially when the floor construction is timber – as it often is in domestic dwellings and some apartments (particularly conversions) – the plasterboard ceiling lining is the equivalent of both the seat belt and/or air bag for the building. When did you ever see a ceiling lining carrying a label advising the owner, or electrician, of this fact? To most members of the public the ceiling lining is primarily an aesthetic item, hiding the structure. In the absence of any label on the construction, what about labelling the product to be fitted?

Stringent consumer laws relating to automotive safety, generally originating from the USA, invariably require a warning on the packaging if there is any possible risk of a car accessory being fitted in a manner that could compromise any of the safety systems. In the construction industry, the responsible component manufacturer – in this case the downlighter manufacturer – may put a warning on, or in, the box, but the guidance will rarely be specific as to what should be done. Probably the worst type of packaging is that which declares the light has been tested, without giving full details as to how and what features need to be incorporated in the installation.

Such packaging places complete responsibility on the installing electrician to establish the way it was tested, and what additional measures are needed to ensure that fire separation is achieved. More worryingly, it is left to the contractor to establish the level of fire resistance needed for the penetrated element, if it is to comply with regulatory guidance, or the declared Fire Strategy. This rarely features in any courses run for the electrical trades. Perhaps a good use of any custodial sentence resulting from a prosecution would be to study the Building Regulations!

When a ceiling lining is critical, then it is possible to make it difficult to fit concealed lights by incorporating steel mesh, either above single layer plasterboard linings or between double layers of boards. While the special tools needed to penetrate this would only extend to metal cutters, hopefully by encountering such a mesh, the lighting fitter will question why it exists in the first place. But this cannot be taken for granted, as even the presence of a steel RSJ immediately behind a plasterboard ceiling may not fail to stop some from completing the task.

In the UK, the Building Regulations are functional; that is the design and construction must be fire-safe, according to the risk that the property and its use represents. But in all cases, there are guidance documents that provide a prescriptive solution to this objective. These take the form of Approved Documents in England & Wales: it was Approved Document P, implemented on 1 January 2005, that placed the responsibility onto the electrician to ensure that his/her fitting of lights and other electrical equipment did not reduce the fire protection or separation levels.

For fire, Approved Document B (AD B) has just undergone a major revision, which went out for public consultation last summer. This draft includes a new Annex G which requires a log book to be completed, in which all items provided for fire performance are readily identified, including their ratings and test evidence. While this is not law. it would, if adopted, give the electrician details of the fire ratings to be maintained. In the case of downlighters, this should identify the need to fit lighting covers/hoods/tents over the light to maintain the fire rating, or to use a correctly tested and rated light. Half of the battle is won, but electricians still have to select a ‘properly’ tested component.

The annual examination of the building – akin to the MOT test – may not be far away either, although ironically this will be unlikely to impact on dwellings, where poorly selected and/or fitted lights could have the most serious consequences. This year, ongoing fire safety legislation changes, so that commercial and public properties have to be regularly risk assessed for compliance with fire safety. This is unlikely to be annually, but it must be at such a frequency that any changes in the building are evaluated for their impact on fire safety requirements.

Currently, the risk assessors performing this function are a disparate group with mixed skills. Hopefully they will soon learn what to look for in respect of protection for the structure needed to compensate for poorly fitted lights. These new millennium ‘fire bobbies’ may, if they do their job properly, keep the errant electrician out of court, or even prison, but they may also cause them to return to site and fit improved lights or additional lighting protection at their own cost. With AD P in existence, they will not be able to claim that the protection was not specified – it is their job to recognise the need.

This brings us to the subject of selecting the correct product(s) for the job. There are no product standards, nor European Technical Approvals, nor bespoke fire test procedures for fire-safe lights or lighting covers, and there will not be for the foreseeable future. The electrician will have to become astute at differentiating between correctly tested and assured products.

Modern building practice has meant that many floor constructions are now much less tolerant of exposure to fire, because modern factory-made composite joists have minimal inherent fire resistance. Many modern joists have an inherent fire resistance measured in minutes, and others permit rapid fire spread from cavity to cavity.

The protection to a floor cavity provided by a ceiling that incorporates a downlighter is governed by the interaction between the light, the ceiling materials and ceiling construction, and any protection provided. A light, protected by a lighting hood/tent/cover, or which embodies its own fire protection, will not afford the same level of protection when installed in wallboard, as it would in Soundbloc/Soundshield – two very visually similar products – let alone in fire performance-enhanced boards, such as Fireline, Fireshield or Glasroc. Two layers of plasterboard often impart three times the level of protection to a floor than a single layer. So a one-hour result of a concealed light in a two-layer board does not translate into a 30-minute result in a single-layer board, especially if the single layer is only of wallboard quality. A component tested in a 15mm lining cannot be used with a 12mm lining, unless a field-of-application report or a test report from an acknowledged fire authority demonstrates that it is safe.

Caveat emptor (buyer beware) has been an established purchasing rule for a long time, but in the case of selecting downlighters, or downlighter protection, rarely has it carried such a responsibility for the electrician. Do not be duped by a low price and a cosy statement that it has been tested. Make sure that the way it was tested is relevant to its intended use or regret it at leisure, or possibly at Her Majesty’s pleasure!

Peter E Jackman IEng MIFireE AIWSc is

technical director of International Fire Consultants.