COSTRUIRE L’AZZARDO. IL CORNICIONE NELL’ARCHITETTURA STORICA, FRA REGOLA E SPERIMENTAZIONE

Abstract

The book explores the historical and constructive aspects of the cornices that, from elements of protection, they can also become elements of degradation and instability due to their form. The structure of the text of this volume consists of three main parts, presenting some technical aspects and issues of uncommon attention. The first part analyzes a discussion about the formal and material values of the cornice; in fact, it presents complex characters and summarizes the problems deriving from formal and constructive requirements of the building envelope, due to the double value of ornamentation (crowning of the building) and functional component (removal system of meteoric water from the façade), also related to an inevitable deterioration, like many other architectural elements jutting out. The second part constitutes, instead, a repertoire of indications for the correct execution of the architectural element, realized according to the perfect “rule of art”. It's an opportunity to present an excursion of about two hundred years on the theme, taken from significant treatises and manuals, which over time have provided rules and dictates “of good construction”, constituting points of reference for the historical construction. Finally, the third part deals with aspects related to the degradation that the shape of cornice can produce on the façade. This evaluation was supported by an experimental study conducted at the University of Palermo, through the creation of an experimental model, calibrating it on the most recurrent forms of cornices founded inside the historic center of Palermo. The data obtained were compared with the pathologies identified by the UNI 11182/2006 and it allowed to draw up synoptic tables through which it’s simple to relate the found degradations with the shape of the cornice molding. Through the identification of exemplary cases and the constitution of a repertoire of formal configurations that contribute to the most recurrent degradation factors, the volume wants to provide specific indications that allow the technical element to be brought back to a configuration compatible with its intrinsic and historical characteristics.