Always within the category of artificial stone materials, the plaster was used for coating the buildings surfaces both outside and inside. Born as the sacrifice surface for the preservation of the covered masonry, over the time has acquired nobility, artistic expression and value of historical evidence. Has been done the attempt to imitate the stone through the artificial composition ("bugnati", fake stones) and finishing (profiles, pigmentation), or the decoration itself (wall paintings, graffiti). It has been possible that the restoration theories and methodologies focus also on this class of material, taking it away from the reinstatement interventions, considered routine maintenance. General speaking, the processes and methods applied for the plastered façades restoration follow the same standards as for the stone façades.
It starts up with the operation of pre-consolidation and securing of parts in danger of collapse (as portions of plaster raised and strongly detached). It continues with the cleanings stage, including sanitation and disinfection, removal of various kinds deposits and over putted substances (repainting, varnishes altered, graffiti and writings acts of vandalism). If necessary, it carries out the surface consolidation (micro-cracks, detachments, defects) and in depth (lesions, adhesion defects between masonry and finishing) by injections of compacting mortars or resins. As final step, the original plaster is protected by compatible products, or with are carried out scialbature or reinstatements , always trying to take into account the final aesthetic presentation. All the available sources are carefully studied, among which are to include diagnostic researches to find out and reproduce the original colors, or that which has been more significant in the history of the building.