Scale a sbalzo in lastre di marmo a Torino nei primi decenni del Novecento

The essay provides some historical coordinates for the study of a type of cantilevered staircase that has only rarely been mentioned in the literature: the cantilevered staircase made of thin marble slabs, developed and widely used in Turin and Northern Italy from the late 19th century through the 1950s. The paper proposes a chronology of use and the reasons behind the short-lasting success of these staircases. Two case studies are examined in depth, one involving an experience of repair of such a staircase, casting light on its static behavior, and on the marble chosen for these peculiar assemblages. The problems arising from the unavoidable brittleness of the slabs are also discussed, with reference to accidents and repairs that occurred since the early days of use of this kind of stair. Keywords Cantilevered staircase; marble slab; 20th century; conservation