by Mauro Civai

The Sala di Balia

Another challenging intervention was that on the cycle of Spinello Aretino in the Sala di Balia, in particular the wall upon which the fresco “Ritorno a Roma di Papa Alessandro III” was situated. It is of note that the painting is positioned on the wall corresponding to the external wall upon which the “Maesta” is located, and when, less than a century later, the council committee decided to use this area, remembering the previous difficulties, they decided to create an added piece of wall designed specifically to house the new painted work. If this strategy resulted that the fresco did not come into direct contact with the external environment, the space between the inner and outer walls was, however, the basis for a slow superficial degradation due to the numerous microclimates in existence around the plasterwork and due to increasing structural collapse due to the weakness of the constructed wall of bricks attached with plaster.

The interventions

The investigations, initiated in the 1960s by the ICR, identified complex constructional phenomena which have consequently had determining effects on the current conditions of the work. In particular the investigations discovered highly conspicuous interventions that had taken place in the 1700s, with every probability that these followed the sensitive movements of the walls and the plaster following the disturbance by earthquakes and consistent with the positioning of large metal bars that perforated the painted surface and were attached onto the wall behind.

Following this ample and in-depth series of studies, it was possible to proceed to the phase of elaborating a detailed project, that initially aimed to consolidate the structure through the installation of a mesh of light material between the inner and outer walls, capable of anchoring the thin wall onto the master wall of the Palazzo and maintaining the crucial circulation of air within the cavity.

Following the completion of this challenging structural intervention, the restoration of the painted surface was begun; this had been severely compromised by the application of synthetic fixative materials during the 1930s.