The Municipality of Viggiù is the owner of the architectural complex of Villa Borromeo, built at the behest of Count Renato Borromeo Arese who in 1840 entrusted its design to the court architect Giacomo Tazzini. In July 2021, due to the breakage of a water pipe on the second floor of the building, the frescoes on the vault of the large hall on the ground floor, called the Octagonal Room, were damaged by water infiltration. The painted ceiling was in fact affected by widespread stains due to the solubilisation of the tannins present in the supporting wooden structure and conveyed to the surface by the water, which made the extraction and cleaning operation particularly laborious which in fact required several cycles of application of absorbent compresses spaced over time. To re-establish pictorial adhesion, since the use of nanosilica is not recommended by the Superintendency, it was decided to operate using an acrylic resin in aqueous emulsion (composed of highly penetrating acrylic nanomolecules) always applied on Kleenex paper. The intervention concluded with the consolidation of the entablature on which the sail depicting Neptune is placed and, in the same area, with the retouching of some drops of color found during work in progress.