A multidisciplinary diagnostic approach preliminary to the restoration of the country church "San Maurizio" located in Ittiri (SS), Italy

Abstract

Background: The knowledge of the structure of an artefact, as well as that of its constituent materials and of the hosting environment surely ensures safe guideline for its restoration. Unfortunately, in most cases, a scientific investigation preliminary to restoration is not accomplished due to its high costs and, as a fact, diagnostics is performed only for very precious artworks. This paper aims to provide a multidisciplinary diagnostic procedure that, although not exhaustive, is rigorous and relatively low cost. It was employed in view of the restoration works on a country church located in Sardinia. A careful inspection of all the architectural elements was carried out in order to highlight structural damages as well as sources of them. One stone and one plaster samples were analysed. The salt content was determined, in two different areas of the church, using three different sampling procedures while only the normed method was used for the determination along the stratigraphy of the sampled plaster. Microclimate monitoring was also carried out. Results: Water infiltration through the roof was observed. Natural stones and artificial building materials used in the basic architecture resulted to have local source. Both the preliminary "by eye" inspection and the optical microscopy revealed several finishing layers in the investigated plaster samples. The salt content, with some exception, resulted rather low. Microclimate parameters show significant variations only in few areas of the building. Conclusions: Damage observed inside the oldest part of the Church seems to be mainly related to water infiltrations through the roof and the lack of an effective drainage of the rainwater due to a previous bad restoration. Masonry from one of the newest rooms, showing a strong biodeterioration, as well as some areas inside the nave, revealed a significantly high sulphate content. Building materials (stone and aggregates of mortars) are of local provenance.