Using structural steel or reinforced concrete one can create large buildings quickly. Portland cement gains strength rapidly. Gypsum plasters set almost instantly. Off-site manufacturing of entire bathrooms and kitchens which are craned into place is increasingly common. Click-together polymeric components even avoid Tadeusz, his nailbag and hammer.
However, lime mortars and lime plasters mean slow building - as does ashlar or cut stone. Lime mortars cure by CO2, and this can take months. When cathedrals were first built, the building season halted in the Autumn, before the first frosts. Recent work was covered in straw and thatched and left to cure for several months. There are no accelerants for hydraulic lime.
The damage to cracked but uncollapsed rib-vaults at Notre Dame will be infinitely harder to repair than the collapsed ones. Those flying buttresses are presently pushing the roofless walls inwards, and a temporary but substantial steel structure will be needed to stabilise the nave - wind loadings could still collapse the fragile structure.
Not to mention finding sufficient European Oak timbers. As an aside, a Nelson-era frigate took about 600 oak trees to build - and we had a fleet of 900 ships. Those oaks were planted in the 17th century by Pepys expressly for that future purpose. We no longer have a reserve of large structural oaks. For the stone, old quarries must be re-opened, masons recruited from all over Europe and the cathedral close will be alive with the clink of stone on bankers.
My own guess is twenty years. At least between fifteen and twenty-five. Something in that scale. Notre Dame will be covered with a vast temporary roof and be encumbered within by a massive steel structural frame for a generation. Macron is a fool and away with the fairies.
And now for the first of my EP election memes - I return to Twitter for such events with all the enthusiasm of a plumber clearing a blocked toilet.
32 comments:
We no longer have a reserve of large structural oaks.
Yes, was wondering about that. I've done two "roof tours" of Lincoln Cathedral - a huge and magnificent Gothic structure. The roof timbers support an 800-ton roof, and the longest individual timber is 12 inches square and 46 feet long. It was cut (IIRC) in about 990AD for an earlier Norman Cathedral and reused in the present building. These days, it's unusual to see an oak tree in its entirety that's any taller than 46 feet and the idea of getting a straight piece more than few feet long seems ludicrous.
France, on the other hand, is blessed with forests on a scale dwarfing the UK so perhaps there's be something they can use, or perhaps imports will provide the timber needed. Wondered if chestnut is strong enough - used in housebuilding, and any number of large chestnuts available.
I think we can safely say if macron gets his way, the cathedral will be, modernised.
Lots of EU glass and steel.
@ Domo
Yes, I was wondering that?
To Raedwald's point: There is a small and very old packhorse bridge that crosses the Shropshire Union canal near the village of Beeston in Cheshire; right by the Shady Oak pub. A couple of years ago, it was deemed unsafe to cross and in need of a rebuild. Quite rightly, Cheshire Council stated that it must be rebuilt using all the original bricks, stones and only using lime mortar. The canal crossing at that point was closed for well over a year and even after it had been reconstructed (lovely job, by the way!) only people - not cars - could cross it for another 6 months in order for the lime mortar to cure and the bridge key-stones to settle in. Well more than a year for a tiny bridge! What chance for Notre Dame?
There was someone on the PM prog yesterday saying it might even costs a couple of billion *insert 'SNORK here*. I know very little about such things but one thing seems clear ; such 'resurrections' take about twice as long to complete as the original took to build and secondly that 2 or 3 billion is going to be nearer 20-30 billion £s or Euros. Infact it could take so long to complete that the final bill may even be not in Euros but $s or even 'New Francs'.
@Domo... It is probably the more honest route to take. We know Macron has a fairly casual attitude to traditions like democracy, religion, nationality and so on.
Imagine this fire had taken place in 900AD, would they try to copy what went before...?
Or would they try to not only improve the concept, but also be more accommodating to updated conditions?
I have not been to that part of Paris, but I am sure a smaller modern structure, like Coventry would be more appropriate.
/.sarc
Not sure the problem is availability of oak pieces per se, both France, Romania and Hungary to name but three countries have as far as I know vast reserves; the problem is obtaining properly seasoned material.
But hey, Macron is on the case so everything will be fine/sarc.
It will be re-located to Strasbourg and consecrated as Mont St Macron.
Good thing if it had to happen that it happened now, with most of the winter storms out of the way. There do seem to be respectable sources on the web who are sceptical about the official explanations so far. Certainly it would appear that the fire started on a small and local scale (as most of them do) before taking hold. If the roof was damaged and the oak was wet then this is odd to start with. Some say the fire fighters took a significant time to arrive, although by all accounts they did a very good job when they got there.
The people doing the repair work say they had knocked off for the day, so it was not them. Well not entirely, sparks, off cuts of hot metal etc can sit and smoulder for a while before becoming obvious. I know of at least one fire on a mine that was caused by someone cutting off bolts with a cutting torch, the red hot ends fell into a rubber lined tank where they smouldered for hours, undetected before bursting into flames long after the workmen had finished.
Anyone heard the reports of a man in a white hard had walking around the roof just after the fire had started. Apparently they were on French mainstream live TV but have not been shown since. Internet conjecture or cover up? Who knows.
The problem being that our leaders lie so often that when they do tell the truth no one believes them.
As for the rebuilding time I agree it will take a generation at least.
I think you are right, it will take more than five years. But I don't think that matters, the quote of 'five years' is normal political 'direction and aspiration setting' speak. No one believes it but 'the job not started takes the longest'. The Frogs are no worse than anyone else in this regard, it is a politician's duty not to tell the bald truth.
What is disappointing is that once again it seems having the builders in looks likely to cause far more damage than they were hired to repair. Our own National Trust has form in this regard. Not sure what is worse, zealous renovators or benign neglect to say nothing of halogen lamps.
As for Erasmus/Housing. A bit of a false dichotomy here. High house prices are built into the UK's economic structure, we dare not build enough and so we certainly won't. Erasmus on the other hand is low cost bunce for gilded youths, before we shackle them to high cost housing.
Five year plan. Where have we heard that before?
Micron years are something like dog & cat years, think it's a ratio of about 7:1 or thereabouts, I won't state the obvious.
@ Charles 08.20 here is the video you mentioned
( https://twitter.com/TipsyPianoBar/status/1117980100782252032?ref_src=twsrc%5Etfw )
@ Jim
"But I don't think that matters, the quote of 'five years' is normal political 'direction and aspiration setting' speak."
Rather like the Biblical 40 days and 40 nights... a 'political 5 years' just means 'a really long time, after I've gone, and are no longer interested in'.
@PC
I heard on the radio he plans to "improve it".
Regarding the bridge, I think that's probably a pointless indulgence, was it a particularly special bridge?
@RW
Our ancestors really didn't share our fascination with their work.
Every generation felt it was their job to tear down and rebuild significant parts of the manor house.
Much of our preservation efforts preserve tat for no particular reason
Great description of the plaster drying etc., clearly close to your heart!
Good meme too :-)
Nah.
"A free trade deal with the EU will be the easiest in history".
Now THAT's fantasy, Raedwald.
@ Domo
Actually it was. I do a lot of trail running in that area and hadn't realised until I started talking to one of the site managers. It is classified as listed (not that I'm any expert) but it also has to carry light traffic because the alternative is a loooong detour. It can never carry large vehicles because the hump-back is just too "humpy" and it is definitely single-file! Some of the packhorse bridges around these parts were build before the canal was dug out because they crossed small water courses. The bridge was built late 1700s.
When St Paul's burned down, it was replaced with a modern building in a completely different style.
Don Cox
We have a cathedral in need of a roof. It is a shame that the wooden roof-frame has gone but that's all it was, and those buggers do burn down every now and again. I wouldn't shirk from a modern answer instead of a faux oak and lead job. If it could be structurally done, and I am sure that it could, I might even leave the hole in the vault - the better to let Himself see in, and us see out.
"A free trade deal with the EU will be the easiest in history".
Now THAT's fantasy, Raedwald. -Anon
When/if we ever get that far the FTD itself will probably be fairly easy as these things go...assuming by then we have a team of negotiators who don't manage to piss off their opposite numbers from the word go as they did the Japanese recently. Arrogance very rarely goes down well in international negotiations, one would have hoped 'we' would have learnt that lesson over the last couple of years, but it appears not.
and lead job Mongoose
That reminds me, they had the former Renovations manageress from Cologne Cathedral on the German news last night and she pointed out that just getting rid of all the lead that had melted and run down was going to be time consuming (ie lotsa euros). I should imagine there are also 'decontamination issues'- no doubt there is relevant EU legislation on the subject...
Ah Jack ... nope. There's no EU environmental lead limit. One of my notable H&S victories ...
You see in London, with 2000 years of continuous occupation, lead levels in the soil are very high - everyone from the Romans onward used if for roofs, pipes, masonry. Consequently, Pb levels in London soil mostly exceed 400ppm. Well, I had a job that involved sandblasting old paint from steel. The debris was tested and found to contain 200ppm of Pb - which I disposed of as contaminated waste. Not good enough for local Enforcers though - they took swabs that indicated surface dust, coating etc also contained lead at this level and insisted I carry out a specialist clean that would have cost a quarter mill.
I had the soil outside the site tested - 500ppm +. Which meant the wind would blow in soil dust more highly contaminated than my site ... Victory.
London lead map here if you're interested https://www.kisspng.com/png-soil-contamination-soil-map-pollution-lead-soil-te-4463217/preview.html
I expect Paris is much the same.
Regarding the lead levels in the London soil.
It just proves once again that fanatically ticking boxes is no substitute for common sense and never will be.
There's no EU environmental lead limit.-Raed
The things one learns here. Somehow though I have a feeling there should have been a 'yet' in your sentence somewhere...
The issue is, that you actually know the answer to the problem Raedwald, whereas one cannot expect a politician of dubious intellect to make a correct decision.
As most people here say, the five year plan is ridiculous, but the ball has started to roll, and a large section of the population are already being told to believe it! The Scots saw that one coming with their disgraceful People's Palace.
On a slightly different note, the <100bn euros obtained by the Catholic church every year should tide over the reconstruction costs for the next generation. I hope there's a cheque in the post from Vatican City as we speak. This will far out-sway the pledges from the handbag-makers and smelly underarm boilers all dribbling at the advertising revenue.
That London Lead map is, of course, fascinating, thank you...I think (sure I was supposed to be doing something else right now ). Apparently The entire Barbican centre could be weighed in profitably at the nearest scrap yard. Islington is encircled by a ring of toxic lead deposits-which probably explains something about some of the borough's population, especially those of the elderly there what have allotments...and you thought Corbyn had dementia?
Bloody hell radders, I'm amazed they didn't make you decontaminate outside!
Sadly, all present historic buildings and monuments will be gone eventually, even Stonehenge and the Pyramids. It's just a matter of time.
I've just been reading up on lime mortars, plasters etc.
If my sources are correct, then I think that you are referring to non-hydraulic ones, Raedwald, which indeed cure by atmospheric CO2 combination.
Hydraulic limes contain calcium disilicate, and can set under water. They are effectively halfway to portland cement.
White portland cement is also used in restoration work - I don't know if that is planned here, or standard for such work in France.
The European oak (Quercus Robur) is widely available throughout mainland Europe as raw material, but the seasoning times for 30cm square timbers, given a seasoning rate of 1-2cm per year will be a lot longer than five years. Make it more like thirty.
Distribution for European oak here; http://www.euforgen.org/species/quercus-robur/
Anyone who has worked 'green' oak knows it is easy, lovely stuff to work - cuts almost like butter. In Suffolk in the past (documented from 16th - 18th C), because folk always take the easiest path, the oak frames of cottages were fabricated and jointed and pegged OFF SITE from green oak - then the skeletal cottages stood in the yard to twist, warp and season for a year or three. The old dowels could then be knocked out, the sections transported and erected on site and re-jointed with permanent pegs.
People for whom finding enough food for the winter is a challenge will not arse about working hard-as-iron seasoned oak.
There's no evidence, but I suspect oak cathedral roofs were made in the same way - built on the ground from green oak as the walls were going up then un-pegged and re-assembled in situ. Steel tools to work seasoned oak, and the limits of human strength, suggest to me that they would not have worked massive seasoned beams.
But well done.
That kept us off the curious case of Julian Assange very well.
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