After the restoration work that lasted for most of the 19th century, following the 1811 fire, major restoration campaigns have been carried out in recent decades: in the 1920s; in 1979 led by the architect Trizzino, and guided by the Superintendency of Cultural and Environmental Heritage of Palermo. On this occasion, the Cathedral’s structure was consolidated (the roofs of the presbytery, the choir and the naves, the vault of the western portico) and work was also carried out on the coffered wooden ceiling. One of the last restoration projects was carried out in the 1990s. The latter, promoted by the Superintendency of Cultural Heritage of the Sicilian Region and the Regional Council, was carried out with the help of the University of Palermo and the ICR, which carried out specific analyses on the Cathedral. The mosaic floors underwent some conservative restoration between 2007 and 2009. In particular, work was carried out on the side walls, as well as in the presbytery.
