La chiesa di Santa Maria delle Grazie al Calcinaio di Cortona. I restauri dei paramenti lapidei tra gli anni ’60 e ’90 del XX secolo

Since decades the church of S.Maria delle Grazie al Calcinaio was badly deteriored on the external walls made of sandstone ashlars, a phenomenon that the Soprintendenza has attempted to oppose on several occasions with the application of different chemical products. This approach aimed at overcoming, or at least significantly limiting, the usual interventions of renew the degraded stone decoration. As part of a research agreement between the Soprintendenza Archeologia, Belle Arti e Paesaggio per le provincie di Siena, Grosseto e Arezzo and the Departments of Earth Sciences and Architecture of the University of Florence, an extensive campaign of diagnostics investigations was launched, in the lab and on site, accompanied by an accurate investigation of the building. Among the works undertaken, the history of the restorations was also conducted through archive research which highlighted the interventions carried out over time, from which the widespread use of chemical products emerged.