Fresco restoration includes the integration of missing plaster. Restorers use different tools and materials for the intervention. Recent research shows that restored plasters have different thermo-hygrometrical behaviors at low temperature and high ambient humidity rate. Field observations of the hygroscopic behavior of different mortar textures showed that textures obtained with hard tools (spatula, wooden float, trowel) have harder, denser surfaces, which favor vapor condensation, while soft tooled finishes (sponge, sponge float) have a rough surface that facilitates absorption and evaporation of moisture. In case of contiguity between two different finishes, the edges of the rougher surface (around a more compact texture) show more damage than the smoother and compact surface. Despite chemical compatibility of mortar compounds, the effect of changes in waterstateon the surfaces causes differential damage, starting from the edge of replastered areas. The durability of plasters applied with different tools, resulting in heterogeneous textures, can be shorter than that of homogeneous textures. Early detection of risk areas, by means of infrared thermography at transient conditions, is very helpful for the preservation of historical buildings without a controlled heating/cooling system, and it offers an improvement in restoration techniques of precious surfaces.
ASTM, ASTM E 96: Standard Test Techniques for Water Vapor Transmission of Materials, West Conshohocken, Pennsylvania, ASTM International, 2005. Camuffo, D., “Church Heating and Preservation of the Cultural Heritage: A Practical Guide to the Pros and Cons of Various Heating Systems,” Il riscaldamento nelle chiese e la conservazione dei beni culturali: guida all’analisi dei pro e dei contro dei vari sistemi di riscaldamento, Milan, Electa Mondadori, 2007. Camuffo, D., E. Pagan, A. Bernardi and F. Becherini, “The Impact of Heating, Lighting and People in Re-using Historical Buildings: A Case Study,” Journal of Cultural Heritage, Vol. 5, 2004, pp. 409–416. CEN, EN 1015-19: Methods of Test for Mortar for Masonry: Determination of Water Vapor of Hardened Rendering and Plastering Mortars, Brussels, Comité Européen de Normalisation, 1998. CEN, EN 1015-18: Methods of Test for Mortar for Masonry: Water Absorption Coefficient Due to Capillary Action of Hardened Mortar, Brussels, Comité Européen de Normalisation, 2004. Cornale, P. and A. Olchini, “Verifica dei trattamenti protettivi maggiormente utilizzati per la pietra di Vicenza mediante analisi dinamica all’ESEM,” II conferenza organizzativa la ricerca applicata ai beni culturali la chimica, l’ambiente, la diagnostica, il restauro e la conservazione, Urbino, Italy, 2002. Croveri, P., L. Dei and J. Cassar, “Metodologie di consolidamento di superfici architettoniche interessate da sali solubili. Il caso di studio delle fortificazioni maltesi: Valutazione dell’efficacia dei trattamenti e criticità,” Scienza e beni culturali XXIII, Venice, Arcadia Ricerche, 2007, pp. 549–558. Della Torre, S., E. Rosina, V. Pracchi, G. Suardi, N. Ludwig, V. Redaelli, A, Sansonetti and R. Negrotti, “Le indagini multispettrali per il riconoscimento telemetrico degli interventi di restauro nelle pitture murali,” XXI convegno internazionale scienza e beni culturali, Venice, Arcadia Ricerche, 2005, pp. 907–913. Gregg, S.J. and K.S.W. Sing, Adsorption, Surface Area and Porosity, second edition, London, Academic Press, 1982. Jornet, A., A. Somaini and A. Romer, “Lime Mortar for Renders: Is There a Relationship between Finishing Technique and Properties?,” International Workshop: Repair Mortars for Historic Masonry, Delft, Netherlands, 2005. Ludwig, N. and E. Rosina, “Restoration Mortars at IRT: Optical and Hygroscopic Properties of Surfaces,” 8th International Conference on Quantitative Infrared Thermography, Padova, Italy, 2006. Ludwig, N., V. Redaelli, E. Rosina and F. Augelli, “Moisture Detection in Wood and Plaster by IR Thermography,” Infrared Physics & Technologies, No. 46, Elsevier, 2004, pp. 161–166. Pardini, C. and P. Tiano, “Valutazione in situ dei trattamenti protettivi per il materiale lapideo,” Proposta di una nuova semplice metodologia, Arkos, Vol. 4, 2003, pp. 32–38. Roels, G., J. Carmeliet and H. Hens, “Modelling Unsaturated Moisture Transport in Heterogeneous Limestone,” Transport in Porous Media, Vol. 52, 2003, pp. 333–350; 351–369. Roels, Staf, Jan Carmeliet and Hugo Hens, Moisture Transfer Properties and Materials Characterization, Hamstad WP1: Final Report, Leuven, Belgium, Hamstad, 2003. Rosina, E., N. Avdelidis, A. Moropoulou, S. Della Torre, V. Pracchi and G. Suardi, “IRT Monitoring in Planned Preservation of Built Cultural Heritage,” 16th World Conference on Nondestructive Testing, Montreal, 2004.
ASTM, ASTM E 96: Standard Test Techniques for Water Vapor Transmission of Materials, West Conshohocken, Pennsylvania, ASTM International, 2005. Camuffo, D., “Church Heating and Preservation of the Cultural Heritage: A Practical Guide to the Pros and Cons of Various Heating Systems,” Il riscaldamento nelle chiese e la conservazione dei beni culturali: guida all’analisi dei pro e dei contro dei vari sistemi di riscaldamento, Milan, Electa Mondadori, 2007. Camuffo, D., E. Pagan, A. Bernardi and F. Becherini, “The Impact of Heating, Lighting and People in Re-using Historical Buildings: A Case Study,” Journal of Cultural Heritage, Vol. 5, 2004, pp. 409–416. CEN, EN 1015-19: Methods of Test for Mortar for Masonry: Determination of Water Vapor of Hardened Rendering and Plastering Mortars, Brussels, Comité Européen de Normalisation, 1998. CEN, EN 1015-18: Methods of Test for Mortar for Masonry: Water Absorption Coefficient Due to Capillary Action of Hardened Mortar, Brussels, Comité Européen de Normalisation, 2004. Cornale, P. and A. Olchini, “Verifica dei trattamenti protettivi maggiormente utilizzati per la pietra di Vicenza mediante analisi dinamica all’ESEM,” II conferenza organizzativa la ricerca applicata ai beni culturali la chimica, l’ambiente, la diagnostica, il restauro e la conservazione, Urbino, Italy, 2002. Croveri, P., L. Dei and J. Cassar, “Metodologie di consolidamento di superfici architettoniche interessate da sali solubili. Il caso di studio delle fortificazioni maltesi: Valutazione dell’efficacia dei trattamenti e criticità,” Scienza e beni culturali XXIII, Venice, Arcadia Ricerche, 2007, pp. 549–558. Della Torre, S., E. Rosina, V. Pracchi, G. Suardi, N. Ludwig, V. Redaelli, A, Sansonetti and R. Negrotti, “Le indagini multispettrali per il riconoscimento telemetrico degli interventi di restauro nelle pitture murali,” XXI convegno internazionale scienza e beni culturali, Venice, Arcadia Ricerche, 2005, pp. 907–913. Gregg, S.J. and K.S.W. Sing, Adsorption, Surface Area and Porosity, second edition, London, Academic Press, 1982. Jornet, A., A. Somaini and A. Romer, “Lime Mortar for Renders: Is There a Relationship between Finishing Technique and Properties?,” International Workshop: Repair Mortars for Historic Masonry, Delft, Netherlands, 2005. Ludwig, N. and E. Rosina, “Restoration Mortars at IRT: Optical and Hygroscopic Properties of Surfaces,” 8th International Conference on Quantitative Infrared Thermography, Padova, Italy, 2006. Ludwig, N., V. Redaelli, E. Rosina and F. Augelli, “Moisture Detection in Wood and Plaster by IR Thermography,” Infrared Physics & Technologies, No. 46, Elsevier, 2004, pp. 161–166. Pardini, C. and P. Tiano, “Valutazione in situ dei trattamenti protettivi per il materiale lapideo,” Proposta di una nuova semplice metodologia, Arkos, Vol. 4, 2003, pp. 32–38. Roels, G., J. Carmeliet and H. Hens, “Modelling Unsaturated Moisture Transport in Heterogeneous Limestone,” Transport in Porous Media, Vol. 52, 2003, pp. 333–350; 351–369. Roels, Staf, Jan Carmeliet and Hugo Hens, Moisture Transfer Properties and Materials Characterization, Hamstad WP1: Final Report, Leuven, Belgium, Hamstad, 2003. Rosina, E., N. Avdelidis, A. Moropoulou, S. Della Torre, V. Pracchi and G. Suardi, “IRT Monitoring in Planned Preservation of Built Cultural Heritage,” 16th World Conference on Nondestructive Testing, Montreal, 2004.