The Terrace of Saturn in Palazzo Vecchio, Florence (Italy): Material Characterisation and Monitoring for Preventive Conservation

Painted between 1557 and 1566 by Giorgio Vasari and Giovanni Stradano, the polychrome wooden ceiling of the Terrace of Saturn at Palazzo Vecchio in Florence (Italy) is one of the case studies of the Smart4CH2 project. During the diagnostic campaign, data from scientific analysis and monitoring of environmental conditions were collected to identify the materials and techniques used and to assess the state of conservation of the ceiling. A multi- analytical characterisation, both in situ and in the laboratory, was performed on the Terrace ceiling. X-Ray Fluorescence (XRF) was adopted as a preliminary on-site investigation, while on the samples collected, Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Raman Spectroscopy and Optical Microscopy (OM) were employed. Pigments, binders, painting technique and restorations were identified. Materials under characterisation have revealed that their majority was applied during previous restoration works and they are affected by several decay processes. Results were combined with data collected by thermo-hygrometric data loggers located close to the ceiling and in the attic too. The analysis of the correlation between diagnostic results and environmental conditions will point out whether the decay processes are still ongoing.