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Ancient Skills Used to Raise Roof Truss at Notre Dame Cathedral

Ancient Skills Used to Raise Roof at Notre Dame Cathedral

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On April 15 2019, Notre Dame cathedral , in Paris, France was destroyed by the flames of a horrible electrical fire. Soon after, scientists from the French national research organization (CNRS) announced a multimillion-euro restoration project of the 850-year-old Catholic treasure. This complex, and very expensive restoration project, was to include a full study and rebuild of the sprawling timber frames that once lined the vast ceiling. Notre Dame cathedral reconstruction work began at the beginning of 2020 but was soon halted by the coronavirus crisis outbreak.

Last Saturday (18/09/2020), using what ABC News calls “precision and boundless energy,” a team of master carpenters hoisted “a three-ton oak truss” into the sky in front of Notre Dame cathedral. Raised using only “ medieval building techniques ,” the timber truss is a copy of the original wooden ceiling structure that was completely destroyed during the devastating April 2019 fire. This fire was so fierce that it climbed the interior walls of the cathedral, reaching the spire and causing it to collapse.

Notre Dame cathedral in flames, after a freak electrical fire in April 2019. (GodefroyParis / CC BY-SA 4.0)

Notre Dame cathedral in flames, after a freak electrical fire in April 2019. (GodefroyParis / CC BY-SA 4.0 )

Rebuilding The Medieval Notre Dame Cathedral Superstructure

In a 2020 Ancient Origins news article, CNRS scientists said they intended to examine “the foundations, timber, and metalwork.” In a Nature.com article, Dr. Yves Gallet, a historian of Gothic architecture at the University of Bordeaux -Montaigne, said the new research project aimed to write a new page in the history of Notre-Dame.”

Notre Dame cathedral’s new page began with the recreation of the traditionally designed monumental roof trusses . The new trusses were conceptualized to stand in honor of the ancient roof timbers that were lost in the 2019 fire, which also severely damaged the cathedral’s once magnificent roof.

The raising of the first giant wooden roof truss coincided with European Heritage Days, one of the most widely celebrated annual cultural events in Europe. The roof truss raising event gave hundreds of history fans in Paris a unique chance to witness mediaeval methods developed and used by carpenters over 800 years ago, as they constructed and raised the first massive triangular wooden frame that will line the new nave ceiling of the superstructure.

The complex carpentry work under the roof of Notre Dame cathedral about a year before the fire. All of this must be redone with new wood and new support stones. (Bernard Hasquenoph / CC BY-SA 4.0)

The complex carpentry work under the roof of Notre Dame cathedral about a year before the fire. All of this must be redone with new wood and new support stones. (Bernard Hasquenoph / CC BY-SA 4.0 )

Ancient Restoration Techniques Only A Few Carpenters Know

Deciding on the materials to be used in the cathedral’s future spire has been hotly debated among French historical authorities, who have been split between traditional and modern designs. They also struggled with the decision of whether the new ceiling trusses should be constructed using “fireproof” cement. However, in July this year it was decided that the 25 new triangular trusses would respect the traditional designs and materials that were used in the original Notre Dame cathedral.

Sourcing the correct type of timber for this specialized construction job was a challenging problem but that was just the beginning. A bigger problem was where to put the trusses as much of the ornate stonework, which once supported the original trusses, was damaged by the fire.

Finding the trees for the massive truss timbers was relatively easy but replacing the stonework was much harder.  Finding stone that is similar to the stone used by the stone masons 850 years ago isn’t easy. And this stone then has to be worked and installed before all the wooden trusses can be put in place.

Massive Roof Truss Raising Was Spectacular And Successful

Florian Carpentier, the Notre Dame cathedral restoration project site manager, oversees a team of craftspeople from Carpenters Without Borders . Speaking with AP News , the building manager explained that the axe team, who felled the trees for the carpenters to cut into shape, had cut down specifically identified trees for the wooden frames or trusses. Carpentier added that the particular style of truss chosen for last weekend’s public display was “a replica of truss No. 7, more advanced that the first six trusses, which were more primitive.”

Last Saturday’s special event brought to mind the gravity-defying skills of medieval craftspeople, who lashed the massive timer frames with hemp ropes and wheeled them through wooden A-frames 850 years ago. The modern version of this process involved rope cables controlled with a modern pulley system, which slowly raised the first giant truss from the ground. When this awesome architectural piece was finally secured in its proper place, carpenters crawled over it like worker ants, polishing the wooden beams . In honor of the traditions of ancient French carpentry guilds, an oak branch was attached to the apex of the triangular structure, symbolizing prosperity.

Top image: Notre Dame cathedral still rising proud above Paris days after the devasting fire of 2019.                   Source: UlyssePixel / Adobe Stock

By Ashley Cowie

Comments

t was a terrible fire that now requires significant funds and time to repair. The work is complicated by the fact that there are many holes in the roof that leak during the rains. Can be retrofitted with modified bitumen roof system - https://tornadoroofingco.com/benefits-self-adhered-modified-bitumen-roof...

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