The opus sectile was in a compromised state of preservation from a conservative and aesthetic point of view. Large squares divide the stone decorations with plant ornamentation and squares with candelabra and birds on racemes. The lithotypes used are yellow of Numidia Egyptian, red porphyry, green porphyry from Greece called serpentine, white limestone called "palombino" and pavonazzetto of Turkish origin. The restoration of the opus sectile took place in several stages. The craftsman composed the decorative stone pattern on a resinous mortar called misturine composed of Greek pitch, wax, etc. Restorers worked on the backs of the fragments of terracotta to increase the adhesion between the mortars. Subsequently, restorers bedded the stone decoration to the wall with a mortar-based lime. At a first examination, they noticed that the work already had several past restorations, one from the medieval period and the other from the 20^th century. Restorers faced a large portion of detached decoration, reassembled them on cement to create a panel with a metal box, and then repositioned them on-site. Over time it created stresses and detachments to the portions of the sectile. First, restorers consolidated the bedding layers. They used a consolidating agent to allow the lime-based mortars to reattach to the bedding layers between the brick part of the wall and the terracotta part. This operation included injecting the consolidating agent between the detachments and the relative voids. They decided not to fill all the holes to protect the structure's weight. This process helped carry out some nailing, which allowed a re-adhesion of the layers. As for the reattachment of the stone portions, restorers consolidated with injections no longer based on lime but with a synthetic resin dissolved in ethyl alcohol. The misturin is water-repellent by its very nature. Once restorers completed the consolidation phase, they removed the cement filling mortar, especially in the upper part of the sectile between the panel and the arch of the apsidal basin of the old restoration. Precisely during the removal of the cement, some surprises emerged. On the border area between the wall and the arch, fragments of the mosaic decoration of the first decorative arch structure materialized. Also, the end of the sectile candelabrum decoration appeared in the lower right part. This process allowed restorers to establish that the entire arch of the chapel was once part of the mosaic decoration. Restorers also proceeded with bonding portions of stone now detached from the misturin through synthetic consolidant use with a higher percentage.

Once restorers completed the consolidation phase, they cleaned the work, tested various methodologies with the help of the scientific research laboratory, and used compresses with Japanese paper and ammonium bicarbonate. This process allowed the removal of a substance as a protective and enlivening agent in previous restorations of plant-oil protein origin. In addition to substance removal, they removed the old waxes and plasters that covered the sectile. At this point, they tackled the restoration of the sectile portion raised on cement. In agreement with the direction of the works, they decided to remove the panel and lighten it from the cement mortar due to several main factors. The excessive weight compromised the stability of the underlying sectile and the insertion of stone elements that were pertinent but in the wrong position. Thanks to a photo acquisition from the Giovenale archives, it shows the exact position and the state of affairs before the detachment occurred. Restorers polished the entire panel and surrounding areas, which allowed for a wall disassembly. The stone material of the panel and the sectile surrounding it was made safe by veiling with a cotton cloth and starch glue. When the glue dried, the panel was light in the portion of the missing central disk reintegrated in cement. The removal has less weight during the disassembly phase and when positioned on the ground. Once placed on the ground with the cement in sight, they started to remove the metal frame containing the back of the panel and then the cement until all the stone elements were free.

Then restorers applied a new light mortar to a self-supporting panel of fiberglass and aluminum (aereolam) with a total weight of about 150 kg compared to the initial one of about 700 kg. Replacing the panel in the exact position, thanks to the photo, helped adjust the weight on the wall structure, and it's no longer on the decoration in sectile below through steel anchors. Once they completed all these operations, they removed the old grout in the cement mortar and plaster. In agreement with the direction of the works, restorers decided to reintegrate all the reconstructible portions to interrupt the decoration where possible. Where the gaps are extensive, restorers decided to leave in sight the preparation: misturine, elements in terra cotta (tuboli), and mortar. The plastering was done in pozzolan and lime for the deep layers and then in lime and marble powder. They smoothed with lime and calcium carbonate to make the surface more similar to marble. Some fillings have engravings to ensure that the three-dimensionality is similar to the portions of the sectile. There are also pictorial integrations in watercolor. In the large gaps in the panel and surrounding areas, restorers chose a neutral mortar that is not too smooth with an appropriate color. The entire sectile has the protection of a synthetic wax that does not alter chromatically and has an easy removal with alcohol.