The choice of parameters for the monitoring and the maintenance of architectural stone surfaces

The maintenance of stone buildings aims to preserve artefacts, to reduce the economic management costs and to extend the lifetime of the restoration interventions. Up to now, there are no clear regulations regarding useful parameters which can be used for evaluating the efficiency of surface treatments for the consolidation and protection of stone. The main goal of this work is to identify possible important “chemical-physical parameters” and their threshold limit values. In this context, the determination of the surface water absorption and colour variation may be important tools for the control and the monitoring over time of the state of conservation of the architecture stone surfaces. These parameters are strongly related not only to the surface conservation state but also to products efficiency. Moreover, they can be easily measured at low cost by specifically trained personnel.