Deterioration of building materials and artworks in the 'Santa Maria della Stella' church, Saluzzo (Italy): Causes of decay and possible remedies. (17th November 2017)

• Record Type: Journal Article
• Authors: Giustetto, Roberto; Moschella, Elena Maria; Cristellotti, Mariano; Costa, Emanuele
• Is Part Of: Studies in conservation. Volume 62:Number 8(2017)
• Page Start: 474
• Page End: 493
• Publication Date: 2017-11-17
• Subjects: Magnesian lime -- Efflorescence -- Incrustation -- Epsomite -- Nesquehonite -- Dypingite -- Hydromagnesite -- Nitratine; Art objects -- Conservation and restoration -- Periodicals; 700.288
• DOI: 10.1080/00393630.2016.1217694
• Languages: English
• ISSNs: 0039-3630

Abstract

Abstract : An in-depth scientific survey revealed the deterioration mechanisms affecting the 'Santa Maria della Stella' church in Saluzzo, Italy, where various salt crystallization processes are strongly damaging the building materials and artworks. Rainwater seepage permeates the vault and interior, causing: (1) epsomite growth as interstitial columnar crystals (resulting in pictorial coating detachment) or superficial, powdery efflorescence; (2) formation of nesquehonite/hydromagnesite crusts on wall paintings; and (3) nitratine growth causing pigment staining and detachment. These processes involve selective Mg 2+ mobilization from magnesian-lime mortars and bacterial-induced formation of nitrates from guano, with consequent precipitation of degrading salts. The study confirms how characterization of all deterioration agents is fundamental to planning a viable cultural heritage conservation and restoration programme.