The stonecutter’s workshop or the geometry in action

What is a vault?

Wikipedia defines a vault as a curved masonry structure made of specially cut stones, supported by walls, pillars or columns, and serving as a roof.

In the collective imagination, vaults have an old-fashioned look. We all have in mind the Romanesque vaults, the cross vaults which gave us moments of emotion during our discoveries in abbeys, cathedrals and other religious buildings.

   Photo: Tourisme Tarn-et-Garonne – Abbeys of Belleperche


At the corner of a square, we discover vaults offering these pedestrian passages which enchant urban strolls. The arches of bridges spanning rivers are also vaults. And finally, in the old houses, the vaults of the cellars offer a decor suitable for the tasting of good wines.

But if we are to believe François Buret, a mason and stonecutter in the South of France, who is holding a workshop for young people, the vaulting technique, which is certainly thousands of years old, is not outdated. Contemporary architecture makes frequent use of it to harmoniously arrange the space of the houses of our time, to create arcades, door or window frames in this authentic material which is stone. And even if mechanisation and new materials have changed the practice of this profession, which he has practised with the same passion for over 40 years, the basic knowledge has not changed.

And transmission is no less important today than it was when he himself was an apprentice and then a Compagnon du devoir. (The Compagnons du devoir are members of a french movement that provides young people, from the age of 15, with training in traditional trades. It is based on apprenticeship, community life and the Tour de France du compagnonnage journey). This is why he likes to train young people through hands-on workshops, to give them a taste for the craft and to help children discover the pleasure of giving birth to a vault in their turn.


The idea of this workshop is to show them that mathematics, and in particular geometry, are essential in order to create, from stones – flat elements, a vault developing in volume in space. To help them in this discovery, he presents them with a finished product, a vault made of Siporex (autoclave-cured cellular concrete).

Then he puts them to « work ». He helps them, as a facilitator, to determine the central point from which they will determine the rays and then to divide the vault into several parts. They will draw a life-size template before cutting the stones to size. The stones will then be placed in a wooden formwork where they will be supported on each other. When the formwork is removed, all that remains is to see that the stones fit together.

            Photos: Fermat Science

It would be very difficult to explain to the (very) young audience the forces that add up to create this balance, but each stone, compressed, will now resist the effort. Later, if they are passionate about it, they will learn to calculate the balance of forces that ensure the stability of the whole. But when they leave this workshop, our apprentices of a day will at least have learned to look at the buildings around them with a different eye.

Kids will discover that they are sensitive to the beauties of architecture. Mission accomplished for François Buret, bricklayer and stonecutter.


Article written by Fermat Science

Credits for the featured image: Wikipedia