# Notre Dame roof collapse -- are the walls in danger of collapsing due to intact flying buttresses?

**URL:** <https://boards.straightdope.com/t/notre-dame-roof-collapse-are-the-walls-in-danger-of-collapsing-due-to-intact-flying-buttresses/832600>\
**Category:** Factual Questions\
**Created:** [April 15, 2019, 11:43pm UTC](https://boards.straightdope.com/t/notre-dame-roof-collapse-are-the-walls-in-danger-of-collapsing-due-to-intact-flying-buttresses/832600 "2019-04-15T23:43:24Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![eschrodinger](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschrodinger/32/122_2.png) [@eschrodinger](https://boards.straightdope.com/u/eschrodinger)\
**Post date:** [April 15, 2019, 11:43pm UTC](https://boards.straightdope.com/t/notre-dame-roof-collapse-are-the-walls-in-danger-of-collapsing-due-to-intact-flying-buttresses/832600/1 "2019-04-15T23:43:24Z")

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As I understand it, the flying buttresses oppose the outward force on the walls of the weight of the roof and vaulting. Assuming the roof and vaulting have collapsed, and the flying buttresses’ are still intact is there now a danger of the buttresses’ weight causing the walls to collapse? If so, how great is that risk?

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**Author:** ![Marvin\_the\_Martian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/marvin_the_martian/32/2898_2.png) [@Marvin\_the\_Martian](https://boards.straightdope.com/u/Marvin_the_Martian)\
**Post date:** [April 16, 2019, 12:45am UTC](https://boards.straightdope.com/t/notre-dame-roof-collapse-are-the-walls-in-danger-of-collapsing-due-to-intact-flying-buttresses/832600/2 "2019-04-16T00:45:29Z")

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Images from inside the cathedral show most of the vaulting intact, so only the wood/lead roof is destroyed (and maybe a lot of the lead just melted and is still up on the vaulting). Hopefully will be enough weight still producing outward force to counter the inward force of the buttresses.

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**Author:** ![Bijou\_Drains](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bijou_drains/32/2814_2.png) [@Bijou\_Drains](https://boards.straightdope.com/u/Bijou_Drains)\
**Post date:** [April 16, 2019, 3:07am UTC](https://boards.straightdope.com/t/notre-dame-roof-collapse-are-the-walls-in-danger-of-collapsing-due-to-intact-flying-buttresses/832600/3 "2019-04-16T03:07:43Z")

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most likely as soon as possible they will put in braces inside if they are needed

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**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\
**Post date:** [April 16, 2019, 8:04am UTC](https://boards.straightdope.com/t/notre-dame-roof-collapse-are-the-walls-in-danger-of-collapsing-due-to-intact-flying-buttresses/832600/4 "2019-04-16T08:04:05Z")

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The workmen were there because there were problems with the stonework. Cracks and crumbling were spreading - [http://www.notredamedeparis.fr/en/](http://www.notredamedeparis.fr/en/) scroll down one page to see.

There must now be serious concerns about further damage caused by the high temperatures.

All this is highly reminiscent of the fire at York Minster, which cost £2.25m (£6.2m today) and took nearly 5 years.