Safe Management of Stone Balconies: an Overview

Stone balconies are structural elements and architectural features mainly used in European and Mediterranean countries. The knowledge and the continuous creation of new materials do not constitute a limit to the use of natural stone in structural works such as balconies: this use is often justified by a mere aesthetic reason in the restoration of historic buildings. As a natural material, the stone is difficult to control in terms of homogeneity and isotropy, it has poor tensile strength and it is difficult to consolidate to ensure adequate structural safety. Thus, first, a research of the main balconies’ collapse events was carried out to understand how much extended and critical the situation is. Then, to understand the phenomena of the falling balconies, the problem was approached from different points of view: besides the structural aspect, the overall process was analyzed with the "What-if" technique, to identify the Hazard Factors. The research confirmed that, in Italy, high numbers of balconies collapsed in recent years and a good percentage includes balconies in stone. The paper discusses several proposals and a solution (pre-compressed corbel) is analyzed and proposed to save both the structural conditions and the aesthetic aspects of the building, ensuring a safe construction and use of stone balconies