Saturday, April 20, 2019
Notre Dame's Wooden Roof
I suppose it would in some sense be more historically accurate, but all of the original wood is gone, and modern wood would not be the same any more than steel would. Plus, the focus of any historical reconstruction should be on the experience of visitors, and nobody went into the attic.
Most of the cathedrals rebuilt after the World Wars have roofs supported by steel beams, including the famously beautiful one at Reims. So far as I know, nobody complains about the lack of authenticity.
Steel roof trusses are safer, stronger, and cheaper. It is true that in some kinds of fires thick wooden beams actually work better, retaining more of their strength when heated but not burned through. That only applies to particular situations, though; in general, as you would expect, steel is more fire-proof.
And then we get to the biggest objection to a wooden roof: where would the wood come from? Medieval technology relied on very thick beams cut from very old trees. By the later Middle Ages special forests had to be set aside all over Europe, usually owned by the crown or the church, where oak trees would be allowed to grow for a century or more to provide that crucial wood. In France today there are, experts say, not enough old oak trees to supply the necessary beams. I am not sure if this includes the trees growing in national parks, but since the point of those parks is to gradually recreate Europe's ancient forests, cutting out the best trees seems like a terrible idea.
It isn't just a matter of going to the lumber yard; a whole forest of ancient oaks would have to be cut. How can that be a good idea when we have a perfectly acceptable substitute? Rebuild in steel.