In 1999 a study of the ceiling revealed various types of damage largely due to water penetration, as well as to inappropriate earlier restoration. Damp in the mortar, the loss of some surface layers and a variety of cracks indicated where the most important work was to be carried out.

The next step, and before embarking on the restoration of the painted areas, was to install environmental control and to study the movement of the cracks using sensors. Infra-red images of the entire ceiling revealed that a significant part of Giordano’s painting still lay beneath the various later repaints.

The ceiling that the restorers encountered revealed the work of different hands, different techniques, areas of damp, stains produced by salt, oil, retouching using gesso, badly integrated areas of repair, etc.