Laboratory and In Situ Control of Cleaning Techniques and Solutions Performed on Stone Façade of the Serbian National Theatre Building

The aim of this paper is to show the holistic process of diagnosing issues on the façade of the Serbian National Theatre building which was used to make recommendations for subsequent cleaning and protection works done in 2021. The building of the Serbian National Theatre (Serbian: Srpsko narodno pozorište) is located in the city of Novi Sad, the cultural and administrative centre of Vojvodina, the northern Serbian autonomous province. The new theatre building was built in 1981, and apart from several ad hoc interventions on the façade of the building, for over 40 years no comprehensive cleaning had been done and there had been no consolidation or protection works on the delicate white stone. The Laboratory for Materials in Cultural Heritage was trusted with the task of preforming holistic characterisation of the façade stone, detecting deterioration mechanisms and proposing adequate conservation methodology. The laboratory’s mobile equipment with non-destructive techniques and laboratory assessment enabled the complete analysis of the façade materials. Following the analysis of the obtained results, recommendation was made in which techniques and agents had to be used for the façade cleaning, ensuring good aesthetic and microstructural compatibility.