SCIENTIFIC PRE-PROJECT STUDIES AND FORMATION OF THE CONSERVATION CONCEPTION FOR THE ASSEMBLY HALL IN THE MAIN BUILDING OF THE LVIV POLYTECHNIC NATIONAL UNIVERSITY

The article highlights the results of the first round of conservation works to return the lost image of the assembly hall (meeting hall of the great senate) – the main building of the oldest building of the university. The purpose of the works is to create the methodology basis to restore the wall painting and sculpture decoration of the hall, to return it to its original authentic appearance from 1880-1884. The decoration of the hall was realized in 1884 by the artist and architect Ivan Dolynskyi, according to the idea of the first rector, architect Julian Zahariewicz. However, the original artistic decoration of the assembly hall was lost in the subsequent periods after the First World War. The walls of the hall and decorative plastic were covered with new paint layers of a nondecorative nature. The first test studies in 2015 showed the possibility of removing layers and opening the original wall painting decoration. They also testified to the need for conservation and restoration works of the authentic wall painting decoration, which in some places had cracks, local losses, and unsatisfactory technical conditions (flaking from plaster). Complex scientific architectural and conservation studies of the interior of the assembly hall were carried out, including the performance of all necessary types of research – from archival searches to soundings in paint coatings and stucco, and laboratory analyzes of materials. Research has revealed the nature of layering and the different states of preservation of the authentic painting layer in all parts of the hall, at different levels of the walls and decor. As a result of research, it was established the possibility of cleaning all walls, decorative stucco, and sculptures by mechanical means. Due to the large volume, it was recommended to divide the cleaning and conservation works into several stages. According to the concept of the discussed and approved project, the following were recommended as the main methods and stages of restoration works: – mechanical cleaning of the entire wall plane; removal of paint coatings to the layer of authentic marbling; also removing putty from cracks and gaps in the plaster; – delicate wiping of the wall surface with distilled water to remove surface contamination; – injection of deep cracks with liquid restorative putty mass; – “bringing” plaster in places of losses, falls and chips, followed by its alignment in the plane of the wall and its priming; – strengthening of the places of the base where there are losses, shedding of the wall painting by the method of its structural strengthening with the help of impregnation with a special priming solution; – restoration reproduction and toning of the wall painting (exclusively within the limits of losses); – after the completion of the reproduction of the wall painting-marbling (when the toning has completely dried), applying a restoration wax-resin mastic to the entire surface of the wall; giving a gloss after the mastic has completely dried; if necessary, mastic can be re-applied on new layers of wall painting. In the article, we reveal the main results of the research work, as well as highlight the key positions of the conservation task and the conceptual project of conservation, and recommendations for planning executive works. We also reveal the process of implementation of conservation works at their first stage - in 2015-2016. The works were carried out by the restoration group of the Department of Architecture and Conservation with the involvement of students.