4. Building materials and installation

4.1 Preparatory work

Certain steps are essential before implementation, such as :

• sorting the slates or lauzes: sorting consists of classifying the lauzes along the lines of the schist, and grouping them by size and thickness;

• checking the quality of the stones: probing is the practice of tapping on the lauze with a hammer (figure 1 ); you can tell by ear whether the lauze is defective;

• adjusting...