HISTORY

(Excerpts from an article by Marcel Poulet for the ceramic and glass magazine)

The Courboissy Brickyard is located in the north of Charny, an area of hedged pastures and meadows that makes up the farthest north-west corner of the regions known as Puisaye and Gâtinais.
Originally, clay was dug nearby (150 m) in a pit that belonged to the manufacturer. It was yellow clay to which was added 10 to 30% sand and 5% grey clay from Moutiers.

The clay was put into a hopper from which it flowed down into a mixer. It was taken by a conveyor belt to a grinder with two vertical steel mullers, or millstones. Once it had been crushed and then pressed through a sieve by the stones, the clay was once again sent on a conveyor belt to the crushing rolls where it would be ground even more finely before being dumped into a mixer with spiral augurs where it was moistened and mixed until homogenous. It was then put through a vacuum extruder and extruded through the die calibrated according to the size of the products to be made.

The bricks were placed on racks and then taken to the drying rooms or into the two hot air dryers, each with a capacity of about 120 m3 (4200 ft.3). Hot air was blown into the dryers through four grates in the floor and circulated by four fans at the ceiling. The hot air was provided by the nearest kilns.

Once dry, the bricks were taken to the kiln to be fired. As the floor of the kiln was only a grate in order to allow the fire to surround the bricks, a temporary floor was laid down as the bricks were removed and was reused for the loading of the new bricks to be fired, being progressively taken back up as the kiln was filled. Bricks were placed on edge in “walls” running perpendicular to the loading door and evenly spaced to allow the heat and flames to spread evenly.

When the kiln was full, the door was sealed with bricks covered in a clay and sand mortar. Three small, cylindrical spy holes were left open to be able to see the colour of the kiln’s load near the end of firing and estimate the temperature.

KILNS

The brickyard had four kilns built at the end of the drying rooms.

  • a kiln of about 30 m3 (1000 ft.3) with 4 fireboxes.
  • a kiln of about 40 m3 (1400 ft.3) with 6 fireboxes.
  • a kiln of about 40 m3 (1400 ft.3) with 6 fireboxes.
  • a kiln of about 40 m3 (1400 ft.3) with 6 fireboxes.

They were down-draught kilns with lateral fireboxes. The fire would go up the chimneys along the walls inside the kiln, curve up under the arch and back down between the stacks of bricks before exiting through the grated flooring and out a trench leading to the chimney that was used by all four kilns, located outside of the buildings.

The firing was divided into two segments. The first day the fires were lit in the fireboxes and fed from one side. On the second day, the fires were lit on the other side and fed while the fires on the first side were also fed but kept low. During this phase, the fireboxes were not fed between 10 pm and 6 am. Then followed a period of intense heating lasting 40 hours, when all the fireboxes were fed roughly every 15 minutes. This brought the temperatures up to about 1300°C (2375°F). This was measured by the colour inside the kiln and also by using small metal rods stuck through the arch of the roof that rested on the stacks of bricks. As the bricks shrank during the firing, the metal rods sank further into the kiln. Index marks noted during past firings made it possible to estimate how much the material had shrunk and how far along the firing was. About 60 steres of wood were used for each firing.

There were usually two firings every week. With four kilns it was possible to organise a rotation that would cut out any wasted time, with one kiln cooling, one being emptied, one being loaded and one waiting at the ready.

After firing, all the fireboxes were carefully sealed using bricks and a clay and sand mortar to prevent them from cooling down too quickly. After three or four days, peep holes, small observation holes at the top of the arch, were opened, and then the top of the door. After a week, the bricks could be taken out.

A FAMILY BUSINESS

Several generations have been involved in this family business. The brickyard has seen four generations of Gauthiers. It was started in 1890 by Désiré Gauthier, the great-grandfather in the line who was an employee at the brickyard at Marchais-Béton (10 km or 6 mi. to the south). He married the owner’s daughter and started his own business in Courboissy. His son, Raymond Gauthier took over from him. Upon Raymond’s death, the business became a limited liability company (SARL) run by his daughter Ginette Sauvageon who passed the baton to her own daughter, Ms Beaufils. Unfortunately, handicraft industries were on a downward slope in the 80s. Economic activity slowed, markedly so in construction, and this led to a noticeable downturn in business. In addition to the economic situation, in 1987 production problems that have yet to be explained fully but which seem to have been caused by defective equipment forced production to shut down for four months followed by trial period resulting in a further loss of customers. At that time, there was merely a semi-detached house in front of the plant that served at one time as an office and the residence for the only living descendant of the family of brick makers.

In 2000, the brickyard was bought by two craftsmen brick makers, Chantal Cailleau and Gilles Nadal. Rather than starting up brick production again, these two turned their attention towards tiles and the traditional tommette flooring bricks and started producing them using traditional, hand-crafted techniques. It is one of a very few factories in France that still uses traditional techniques. Except for preparing and shaping the clay into blocks, the rest of the work remains very similar to what it was when the factory was built more than a century ago.

The blocks of clay are cut using a piano wire to form slabs that are then pressed into square or hexagonal moulds. After drying for three weeks on racks, the pieces are put in the kiln on their facing on top of firebrick supports. Then they are fired for two days and one night. Firing them at 1150°C (2100°F) makes less porous, harder tiles.

There are many advantages to the way tiles are produced at Courboissy; the tiles are special, something that is rare in today’s market, which means that they are sought out for restoration projects and for new construction for buildings with regional character. The company is still truly one of craftsmen, both because of the small number of workers who do multiple jobs and because much of the work in the operation is still done manually.

Terres Cuites de Courboissy - Hameau de Courboissy - 89120 Charny - Tél. 03 86 63 71 20 - Fax 03 86 63 66 54 -