Progetto di restauro conservativo della facciata della chiesa di Santa Maria di Nazareth (Vulgo degli Scalzi) - Venezia: criteri di analisi, rilievo, diagnostica e sperimentazione nel cantiere di restauro

The facade of the Church of Santa Maria di Nazareth is unique in the context of the city of Venice as it is entirely made of Carrara marble, a lithotype rarely used in the Venetian environment. This limestone with a saccharoid structure proved to be unsuitable in particular due to its outside location which subjected it to the aggressive lagoon climate as well as to dramatic thermal shocks due to both solar radiation and frost. The complexity of this restoration work (2014-2018) was to obtain an effective consolidation of the degraded stone support, as well as to reduce the causes of alteration of the marble linked to water, both meteoric and condensation. The first diagnostic investigations brought to light a vast degenerative phenomenon: all the marble decorative apparatus appeared very degraded, characterized by the dissolution and pulverization of matter beneath an apparently compact cortical surface, for a depth varying from 7 to 12 cm. Experimental research was therefore undertaken as this dramatic condition of the marble was not reflected in specialized literature. The guiding line of the restoration project has therefore been oriented towards the use of traditional materials and technologies with the combination of innovative synthetic and inorganic materials widely supported by exhaustive experimentation.