The roofers arrived at 8.00am yesterday (I repeat - 8 in the morning, while I was still in my dressing gown) and got straight into work. All the old slates were off the roof over the back half of the house by midday, and by going home time the 2 chevrons which needed to be replaced were sorted, and the aluminium heat resistant foil had been nailed in place. This is really impressive - all(!) that needs doing on that section now is replacing the voliges (battens) and attaching the new slates. They will also be installing a chapeau on the decompression pipe for the WC while they are in that section.
looking towards the staircase tower.
is used to reduce the heat coming in through the slates.
(Assuming summer ever arrives!)
I hope that explains it. (In fact, I hope it's right - it took a while for me to get my head around the fact that they were prepared to trust themselves to such an item!)
For guidance on French roofing terms, here is a good place to start.
Update on my father: He is out of intensive care and looking forwards to food - ice is all he has been allowed for the past 4 days. He has a little TV on which he can watch the news, so maybe he isn't quite as bored as he was.