Witold Rybczynski's recent post about the tragic fire at Notre-Dame de Paris provides an interesting summary of cathedral construction techniques over the years:
The Paris fire is also a reminder of what a weird hybrid structure Gothic cathedrals really are. The ancient Romans roofed their basilicas and baths with concrete vaults (the Pantheon with a dome), and the Byzantines used thin domes and vaults of brick. Over time, builders lost these skills and Romanesque cathedrals were roofed with exposed timber rafters like big barns. This made the buildings highly susceptible to fire, often caused by lightning strikes. The solution, pioneered at Durham Cathedral in the 11th century, was to build a lightweight ribbed stone vault over the nave. The timber roof remained, so the vault had no structural function (except to support itself) but it separated the interior from the flammable roof above. This was largely effective as the April 15 fire shows.
Below is an image from the WSJ depicting Notre-Dame's timber rafters and showing the extent of the area consumed by the fire. Fortunately, relatively little of the cathedral was actually destroyed.
Going forward, there will almost certainly be a debate about how the roof and spire should be rebuilt. What materials and construction methods are appropriate for this emblem of Christianity and French culture?
But I agree with Witold in that "there is nothing inauthentic about rebuilding."
It is common to lament that buildings simply aren't built like they used to be. But this is not a new phenomenon. Construction methods change, as do the skills of builders.
There may have been critics in the 1220's complaining about how the cathedral's roof was built using wood, instead of concrete or brick vaulting. But that's what was relevant at the time.
We also know that there have been periods of time since its construction where Notre-Dame simply languished. In fact, some have argued that this week's fire was the result of decades of neglect.
But Victor Hugo once wrote that, “great buildings, like great mountains, are the work of centuries." Despite what unfortunately happened this week, that remains true of Notre-Dame de Paris.
