Detecting and mapping detachments in mural paintings by non-invasive acoustic technique: measurements in antique sites in Rome and Florence

The most frequent cause of damage in mural paintings, and particularly in antique frescos, is represented by the presence of detachments. An accurate diagnosis of damages and the successive evaluation of consolidation treatments are fundamental for the protection of many masterpieces. A special apparatus for the detection of detachments in mural paintings has been realised in the framework of the Italian Special Project “Safeguard of Cultural Heritage” in order to satisfy the above objectives. A novel non-invasive acoustic technique displays in acoustic images the presence of surface anomalies such as detachments and fractures. A set of laboratory tests were carried out, employing artificially-made models of detachments, in order to validate the novel acoustic method, and two studies were performed on the XIII century frescos in the little church of St. Passera in Rome, and on the XVI century frescos painted by Giorgio Vasari in his house in Florence.