Valutazione in situ dei trattamenti protettivi per il materiale lapideo. Proposta di una nuova semplice metodologia

There are few portable diagnostic tools available on the market for investigating the effectiveness of conservation treatments on cultural heritage. The evaluation of protective water repellent products applied to monuments and historical buildings can be performed through the measurement of the amount of water absorbed by the treated stone. The existing methodologies, based on the application of the Karsten tube or the pipette, have shown some technical difficulties that hinder practical use. In order to overcome this problem, a new method based on the contact sponge has been developed and tested in the Istituto per la Conservazione e Valorizzazione dei Beni Culturali. Results have indicated the affordable, reliable and easy application of this method, especially for in situ or outdoor testing. Therefore, the procedure is recommended for the evaluation of protective treatments applied to historic buildings. The article includes experimental results and the proposed methodology for carrying out the test. Two protectives were tested (Silirain 50 and Wacker 290) on various stones.