11 Jul Enough is enough
Old or new, all buildings are at an increased risk of fire during refurbishment. Here, Paul Henson, Sales and Marketing Director at Ramtech Electronics, looks at the importance of protecting occupants and assets during construction work.
2019 should go down in history as a turning point for fire safety on refurbishment and construction projects as a result of the devastation at Notre Dame Cathedral. The massive fire of April 15th engulfed the upper parts of Paris’ soaring 12th Century cathedral as it was undergoing a €6 million renovation, threatening one of the greatest architectural treasures of the western world. The flames destroyed the cathedral’s spire and spread to one of its landmark rectangular towers – a stark reminder to construction, refurbishment and insurance companies of the cost of fires. Indeed, the UK government estimates that construction firms in England and Wales are affected by 104,000 fires each year, equating to 11 fires every day.
Investigators believe that the fire 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, 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 causes. If the fire is considered to have started due to negligence during refurbishment works, the companies involved may be liable.
The real question, though, is: how have we ended up in a situation where one of the world’s most iconic and treasured buildings has been devastated by fire, and with it priceless and irreplaceable works of art lost forever. Mind you, it’s not an isolated incident because only last year, Glasgow School of Art, the seminal building by Scottish architect Charles Rennie Mackintosh was engulfed by fire, just four years after it was severely damaged by another blaze!
Fire during refurbishment isn’t just restricted to older buildings, either. In 2017 a huge fire broke out in the Dubai Torch, one of the world’s tallest residential skyscrapers, whilst parts of the building were still being refurbished following the last fire in 2015.
Considering the number of buildings that are lost to fire during refurbishment works each year, culminating most recently by the events in Paris, one would have thought it would galvanise us all to say; enough is enough.
Old or new, the risks are the same
The danger with many refurbishment projects is that the fixed, wired fire alarm that is used when the building is occupied 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 disconnect the fire alarm system! False economy, indeed. 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 exists 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.
EN54 compliant wireless fire alarm systems have been available for some years now and are regularly used 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.
Conversely, if a temporary fire alarm system had been deployed at Notre Dame the outcome could have been very different; a wireless fire alarm system comprises manual fire alarm call points that are installed on site in accordance with the project’s Fire Plan. These call points are designed so that the system is interlinked, meaning that all areas receive the same audible and visual alert signal, even if the fire is contained to 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.
When a fire is detected – either by a person activating a manual call point or via the heat/smoke detectors – it triggers a site-wide alarm and sends an alert to nominated personnel. This enables immediate evacuation, saving lives, and rescue services can be notified at the earliest opportunity. That’s important because minutes are critical – when the flames at Notre Dame were first detected they were already three metres high and out of control.
Preventing electrical fires
Now, let’s say 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. The most common cause is 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 1000°C, well above the ignition point of many adjacent combustibles such as timber, PVC cable insulation and plastic consumer unit enclosures.
Many mistakenly believe that the presence of a residual current device (RCD) would prevent these fires, but a report by the Department of Trade and Industry (DTI) 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 residual current breakers with over current protection (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 result in a fire. The range has been independently tested and is compliant with all applicable statutory European regulations and requirements.
When it comes to emergency preparedness, EN54-compliant wireless fire alarm technology provides an effective way of protecting new and old buildings during construction work – the devastating fire at Notre Dame Cathedral and other high profile fires across the Middle East have prompted many to seek better fire prevention systems; they could do worse than take a lead
And, even before a situation escalates to activation of the fire alarm system, there are now proactive ways of eliminating the thousands of electrical fires that occur each year, many on construction and refurbishment projects; WES Hotspot represents the biggest step change in fire safety since the introduction of smoke alarms. Fitting this type of technology, in combination with an EN54-compliant wireless fire alarm system, offers a cost effective method of saving lives, safeguarding national treasures and protecting clients’ assets.”