La cupola della rotonda del Palladio, problematiche di restauro degli elementi ferrosi a supporto statico delle statue a sbalzo e delle presenze ferrose strutturali all’interno delle masse plastiche

Before starting the restoration of the dome of Villa Capra Almerigo, also known as "La Rotonda", designed by Palladio, the historical research and especially the stratigraphic campaign realized in 2007 allowed to re-interprete completely the various periods of execution of all the decorations. The complexity in the overlapping of the various decorations gave a sense to the presence of metal materials inside the sculptural masses, especially for the overhang ones, and even more to the presence of metal supports with a static stiffening function, most probably installed after the realization. Therefore, at the time of the conservative intervention, it was possible to develop a critical historical analysis that allowed to understand previous restorations works involving the stucco and the internal metal parts. The main issue was evaluating if the restoration of original anchor bolts and the addition of new supports was an appropriate method or not. After various experiences characterized by tests and mistakes, it was considered opportune first of all to maintain intact the static supports of the sculptural mass and then to maintain, where possible, all the existing iron wires to keep their function at least in terms of safety. In a second time, it was decided to intervene where the statues showed signs of discontinuity, to implement a solution more focused to those critical points which were showing that previous support system was no longer guaranteeing static safety. The third application regarded the restoration of the ferrous material, used initially by the stucco workers to reinforce, with an internal wooden structure, the static capacity of the plastic mass.