Scandole from Aosta: a peculiar glaze roof covering. Characterization of the traditional materials and evaluation of the possible compatibility of newly manufactured glazed tiles.

Abstract

The thesis focuses on the study of the scandole of the "House of the Vineyards"; located in Aosta. The building was constructed in the late eighteenth century by the noble Passerin D'Entrèves family and it is currently owned by the Aosta Valley region. Scandole are glazed ceramic tiles used for covering building roots and represent a unique decoration example in this geographic area. The tiles are usually covered with lead-based glaze to waterproof them and to create colourful patterns. Considering that the “House of the Vineyards” is under restoration, starting from the definition of the materials and technologies of the original tiles, the main aim of the thesis is to characterize and evaluate the compatibility and durability of the newly designed tiles produced by Castellamonte artisans. The ceramic body was analysed with micro Raman, Fourier-transform infrared spectroscopy (FTIR-ATR) and X-Ray Fluoresence Spectrometery (XRF) for the chemical-mineralogical characterization, while Thermogravimetry and Differential Scanning Calorimetry (TG-DSC) was used to define its firing temperature. The glaze was characterised using Colorimetry and Fiber Optics Reflectance Spectroscopy (FORS), micro Raman and XRF. Considering the climate present in Aosta, an original tile and a new tile were subjected to freezing and thawing cycles in order to understand and compare the resistance over time. Possible damages of the glassed and the ceramic body were evaluated in terms of colorimetric and morphological variations also based on microscopic and macroscopic observation.