Could passive fire protection have saved Notre Dame?
The fire at Notre Dame Cathedral on 15th of April this year will hardly be news to you at this point. Thankfully the fire claimed no lives, but there was a large outpouring of grief at the partial loss of such an iconic building.
Notre Dame is considered one of the best symbols of French Gothic architecture and means “Our Lady of Paris”. Consecrated to the Virgin Mary and full of rose windows, decorative sculptures and even a crypt, it’s easy to see why this piece of history is beloved by people the world over – particularly for those of the Catholic faith.
How did the Notre Dame catch fire?
Rumours were flying once the fire broke out at Notre Dame, with the finger of blame being pointed to recent restoration works being carried out. This has been refuted by the company carrying out the works, who explained that there was no soldering or welding occurring at that time, nor were their people even on the site at the time of the fire.
It has since been suspected that an electrical fault, causing sparks, could have been to blame, with drones taking thermal images showing the fire may have originated somewhere close to the spire. However, until investigators can access the site to perform a full investigation – structural safety and water damage need to be addressed first – the exact cause of the fire will remain unknown.
Why did the Notre Dame fire spread so quickly?
Anyone watching the footage as the fire unfolded will know that it spread quickly. Initially, the sounding of the alarm was inspected but no fire was found, only when it sounded again later did guards find flames, but the alarm needed raising manually with a call to the authorities. From this point, the fire brigade was notified and was on the site within 10 minutes, however, the fire had already technically been underway for well over half an hour.
One of the key reasons the fire spread so quickly is due to the materials and the age of said materials. A major issue for many gothic cathedrals is the fact that wood is used for the large roof spaces, often this wood is old and powdery which can be a real headache from a fire protection perspective. Lead roofing probably helped to keep air out until it reached its melting point, but once the lead ruptured this will have allowed more oxygen to flow and assist in the spread of the fire.
Fire stopping, often used as part of passive fire protection, is notoriously difficult to implement successfully when it comes to structures which are centuries old. There are limitations to how much work you can do on these buildings, which means many gaps and spaces which provide ventilation are impossible to secure from a fire safety perspective. Had the fire been isolated – through fire stopping – to one portion of the building, it would have been much easier to tackle the flames and protect other areas of the building.
What challenges did the Paris firefighters face?
There were two main challenges for the firefighters in Paris tasked with saving this national, and indeed global, treasure.
The first is the sheer age of the building and the materials involved. Bombarding the fire from the air, as some people suggested, would be unpredictable in terms of results. There is the risk it damages the structure more because of the sheer force of water or other suppressants on weakened materials – not ideal when trying to preserve such an iconic building – and it would only take the release to be off by a few metres to make it miss the key targets, rendering it a useless and potentially dangerous exercise if it hit other buildings.
The second challenge would have been the height of the building – 69 metres high while the spire remained intact. The main aim when trying to stop a fire is to remove one element of the fire triangle: oxygen, fuel and heat – none of which could be controlled easily with such a tall, old and partially wooden structure. Aerially angled hoses would have been nearly impossible to make an impact with, leaving only the option of tackling the fire from inside.
Going inside to battle the blaze will have been fraught with difficulties, with old beams and stone falling all around. Indeed, there were several injuries to respondents when carrying out the efforts to save the building – luckily there were no fatalities.
What we can learn from the Notre Dame fire
Firstly, the Parisian firefighters should be highly praised for their brave efforts in saving a lot of the structure. They risked their lives, working quickly and diligently to get the fire under control. Efforts are underway to plan the reconstruction of the cathedral, with one idea being to create a glass roof and add a modern tilt to the building – much like the glass pyramid on the Louvre.
Aside from this, the other main lesson is that older, historic buildings need a lot of careful thought. In fact, it’s preferable that any old wooden structures are restored using reinforced concrete to provide stability and greater resistance to fire.
Fire stopping, as detailed in one of our previous pieces, is something which should also be considered where possible – though this is understandably tough and we aren’t aware of what measures Notre Dame Cathedral had in place. This process of fire stopping would include all, or some combination, of the following:
Most modern buildings are developed with these types of features already in mind, but Notre Dame shows how important it is for buildings to take the necessary precautions when it comes to fire safety. While there has been a deluge of donations for the restoration and repair of such a sacred and iconic building, many ordinary commercial buildings wouldn’t get the same kind of support to recover and would cease to operate, making fire stopping a crucial investment to protect a business.
For more information on fire stopping, you can visit our page here, or contact us to discuss passive fire protection for your premises.