The striking characteristic of the famous chateaux and old buildings of the Périgord Noir is not just that they are built with beautiful limestone, but that their roofs are made of the same stone.
It is known as a lauze roof, a style unique to the area east of the Dordogne, and just one man and his son specialise in it.
Thierry and Florian Chapoulie are called on to restore roofs both for national heritage sites (monuments historiques) and for private owners – and their order books are full for the next eight years.
I met up with them deep in the countryside as they restored the roof of the ancient bread oven of a private house.
“We use the same techniques that were used 300 years ago,” said Mr Chapoulie senior. “Our only tool is a hammer, which we use to shape each stone tile so that it fits perfectly with the others.
“We do it by ear, listening to the sound of the hammer on the stone, which tells us just how it will break when we hit it. Every stone is different and has to be treated separately.
“It takes 10 years to be taught all aspects of this job. There are no schools, you learn by doing it. I learned from my father, who learned from my grandfather, and now I am passing on the skill to my 23-year-old son. It is hard, physical work, but we are immensely proud to have this special savoir faire.”
Other regions use stone for roofing, and the word lauze is used everywhere to mean a stone tile, but he does not think there is anywhere else in France where the roofs are built with almost horizontal flat slabs laid on top of each other.
“At the base, the slabs are laid 80cm deep on the supporting wall, and then built up and interleaved to the apex where they will be 20cm deep,” he said. “It is a dry-stone technique and we do not use cement, other than perhaps on the corners. This allows the roof to breathe, so that any humidity that gets in will be allowed to dry out.
“We have to get it just right so that it will not let in the rain, and the slope is such that the tiles hold together. It is slow and complex. On average, one person will roof just one square metre in one day.
“It is hugely weighty when finished and there can be from 800 kilos up to well over a tonne of stone for each square metre. In a week, we move about 200 tonnes of stone each – no need for us to go to the gym!”
He said a lauze roof should last about 150 years. It is the wood that gives out first.
Oak is used for the main frame, with chestnut horizontal runners in between, on to which the stone is laid.
He showed me part of the hillside that had been cut away to build the house and the bread oven he was working on.
The limestone was naturally formed in horizontal strata of six to 15cm, separated by breaks in the rock.
You could see that if you dug it out you would have the raw material for the lauze.
“This is why this technique was used,” he said. “People used materials they had at hand. At eye level there are the slabs for the roof. A little deeper and the stone is in larger pieces for the walls and deeper still are much bigger blocks, which could be used for cornices. On top there is soil and the trees to be used for the carpentry.
“I work in a 30km radius of where this kind of rock formation can be found. Beyond that, other roofing solutions were used. In the neighbouring Corrèze, there was slate. Further to the west, around Bergerac, there was clay and so they made their own tiles. Nowadays we quarry very little new stone. Most is reused from the roof we are working on or others that have been abandoned.”
The hammers they use are individually crafted. “We buy them off the shelf but then take them to be re-forged by a blacksmith so the weight is balanced correctly for our own use. They have to be re-forged every two or three jobs.”
The attitude to lauze has changed dramatically over the past 50 years.
Mr Chapoulie said: “In the 1960s, these roofs were associated with poverty and anyone who could would take them down and replace them with shiny new manufactured tiles.
“Now it has changed, so that only the very rich can afford them. In conservation areas, it is obligatory to replace lauze with lauze and I know people who have had to sell their house because they could not afford to restore their roof.”
He says it is expensive because creating a lauze roof is a lengthy procedure.
He would not give a price, as he says it all depends on access to the roof and the state of the timbers, which he gets skilled carpenters to work on.
But he did admit that it is 10 times more expensive than slate.
The Chapoulies have worked on all the prestigious tourist buildings in the region: Marqueyssac; Beynac castle; Saint Geniès, where they are based; and Castelnaud, the highest of them all.
“You have to have a good head for heights, and not mind hard work, but it is rewarding and a pleasure to work in the open air,” said Mr Chapoulie.
“During the summer, we were so high up at Castelnaud that we were above the level of the mist rising from the Dordogne.
“Suddenly, hot-air balloons appeared through the cloud and it was stunning.
“You don’t get views like that working in an office.”