Fires occur all too often during refurbishment work – Notre Dame is a case in point and only last year the Glasgow School of Art was destroyed by fire during building work. This article looks at the importance of protecting all buildings, including historic and heritage structures, during refurbishment.
Irrespective of how old or grand a heritage building is, it is not immune to fire. The appalling incident at Notre Dame is an example of why, when it comes to building refurbishments, we have to be extra vigilant.
Here in the UK, Glasgow School of Art, not to mention a number of other significant heritage buildings, have been destroyed by fire over the last 12 months. The incident at Notre Dame Cathedral in April engulfed the upper parts of the 12th-century cathedral as it was undergoing a €6 million renovation, threatening one of the greatest architectural treasures of the western world. Set against these high-profile incidents is the UK Government’s estimate that construction firms are affected by 104,000 fires each year, equating to 11 fires every day.
Investigators believe that the fire at Notre Dame started at the centre of the cathedral’s roof towards the base of the iconic spire. Although the exact cause is yet to be determined, it appears to be in the vicinity of the refurbishment works to replace lead roof elements. There is also the possibility that it was caused by a fault in an electrical circuit associated with these works. By the time the flames were first noticed at around 6.43pm they were already raging out of control and vital minutes that could have been used to tackle a smaller blaze were lost.
There will now be a mandatory investigation into the cause. If the fire is considered to have started due to negligence during refurbishment works, the companies involved may be liable.
Fire alarms are there for a reason
The fixed, wired fire alarm on many refurbishment projects is disconnected to expedite works. All too often, decision makers don’t consider the elevated risks of fire during refurbishment (welding, hot works, grinding/cutting etc.) when they decide to take this course of action! That is false economy because the cost of repairing fire damage even on a standard commercial building is very costly and results in severe project delays.
Frustratingly, legislative guidance does already exist for fire alarms on construction and refurbishment projects, which, if followed, would dramatically improve fire safety and prevent many incidents escalating to something far worse.
JCOP (Joint Code of Practice) created a step change in fire safety on site by clarifying the need for an EN 54-compliant fire-alarm system. Version 9 of Fire Prevention on Construction Sites; The Joint Code of Practice on the Protection from Fire of Construction Sites and Buildings Undergoing Renovation (JCOP) contains the advice; Components of automatic fire detection and alarm systems should be marked as complying with EN 54 (paragraph 13.8). JCOP is not prescriptive on whether the system should be wired or wireless although the latter offers significant benefits because it is easy to set up – requiring no specialist trades – and avoids drilling holes in listed or historic structures or trailing electrical cables.
A number of leading insurers to the construction sector have made it clear that there is an ‘expectation that customers comply with JCOP guidelines as far as is practicable and reasonable’. In essence, that means there is an expectation that all construction and refurbishment projects will have a fully compliant fire-alarm system, meaning it carries CE marking. As we now suspect, Notre Dame did not have a fire-alarm system in the refurbishment parts, otherwise the flames would have been detected much earlier.
EN 54-compliant products such as our WES3 wireless fire-alarm system are used regularly by over half of the top 100 construction firms in the UK. Despite this, localised decisions can still be made based on other factors and even though wireless fire alarms are a fraction of the cost of the project and easy to set up, a short-sighted approach can sometimes be taken.
EN 54-compliant wireless fire-alarm systems
If a temporary fire-alarm system had been deployed at Notre Dame, the outcome could have been very different. The call points in a wireless fire-alarm system are interlinked, meaning that all areas receive the same audible and visual alert signal, even if the fire is contained in just one of them. Incorporating heat or smoke detectors into the system provides automatic cover 24/7, ensuring that the site is protected even when personnel are not present. No wires or drilling into the historic fabric of the building are necessary. An ability to add or remove units means that personnel in all areas of the building receive the same audible alarm, ensuring that everyone present can evacuate to a place of safety.
If the Notre Dame fire was caused by an electrical fault – and in fact, there are 25,000 electrical fires in a country the size of the UK each year – there is now technology available that might have prevented it escalating to a fire. The most common causes are resistive heat build-up due to loose connections, faulty appliances or overloaded sockets and distribution boards, all of which are exacerbated on refurbishment projects due to, for example, use of high-capacity power tools. This resistive heating of connections can generate heat in excess of 1,000°C, well above the ignition point of many adjacent combustibles such as timber, PVC cable insulation and plastic consumer-unit enclosures. Many people mistakenly believe that the presence of an RCD would prevent these fires, but a report by the DTI (Department of Trade and Industry) in the UK estimates that only 20% of all electrical fires could be prevented by the presence of an RCD. In simple terms, Circuit Breakers, RCDs and RCBOs are unable to detect resistive heat (which causes the other 80% of fires). RCDs are designed principally to avoid a person from being electrocuted and cannot detect the elevated temperatures generated by resistive heating.
As a result of this anomaly, we developed WES Hotspot incorporating Thermarestor technology, which works by activating as soon as abnormal heat (80ºC ± 5°C) is detected. Once activated, these Single and Multi-Point Sensors can either automatically isolate the circuit supply by operating an RCD or else provide a signal to an alarm system – long before the temperature can increase to the point of ignition. It can be connected to virtually any system to provide nominated personnel with instant notification or disconnect the electrical supply if the site is vacated, before it results in a fire. The range has been independently tested and is compliant with all applicable statutory European regulations and requirements.
Even now, fire safety on construction and refurbishment projects tends to operate wholly independently, with each project having its own set of manually based procedures. More recently, with an ongoing focus on personnel safety and increased attention to setting benchmarks for risk management from the insurance industry, there has been a drive towards harmonisation. JCOP has created a common safety platform across Europe. Incidents such as Notre Dame will hopefully encourage more people to use this guidance.
So what happens now? By taking a planned approach to fire safety and utilising proactive (WES Hotspot) and reactive (WES3) technology to protect refurbishments and construction projects, both employees and stakeholders will have confidence that this area has been taken seriously. And, as with all things involving risk, the best time to act is before it is needed. Following the Notre Dame fire, Tibor Navracsics, the European Union’s top culture official, summed it up well: ‘We should never forget that there is also a cost of non-action, lack of maintenance or lack of prevention.’
For more information, go to www.wesfire.com