Analysis of the state of conservation of historical plasterwork through visual inspection and non-destructive tests. The case of the upper frieze of the Toledanos Room (The Royal Alcázar of Seville, Spain)

Abstract

State of conservation studies carried out before rehabilitation and restoration interventions constitute solid support to make decisions about architectural heritage. In this way, the study of historical plasterwork has been performed through non-destructive tests by measuring environmental conditions and surface properties, taking thermographic images, mapping risks by indicating cavities, cracks and metal fixings -among others- and checking the stability of the present polychrome.This method was applied in the plasterwork of the upper frieze of the Toledanos Room, in the Royal Alcázar of Seville, due to the relevance of the building and its decorative coatings, and established parameters to assess the state of conservation of both, the Royal Alcázar of Seville plasterwork and other heritage buildings with similar coatings.The compilation and analysis of all the results presented in this paper show a positive assessment of the stability and conservation of the frieze plasterwork. Thermohygrometric conditions and physical-mechanical properties are acceptable, vertical cracks – sometimes of large dimensions and also great depth-are stabilized and apparently do not affect the structural integrity and polychromies studied are mostly unstable and re-chromatics were widely used in previously inpainting to imitate reliefs inadequately.