Restoration is a traumatic event for a monument which should always be avoided, except in the case of unforeseeable events that cause more or less serious damage to the monument.
Restoration should be replaced by continuous and careful maintenance work to prevent the accentuation of any deterioration processes which are, however, inevitable though the action of weather and environmental factors. Nature has provided the materials with which man can create manufactured products and, in the absence of regular maintenance by man, nature will tend to repossess what is hers.
Maintenance work must be carried out regularly, frequently and carefully, using traditional materials, applied using traditional techniques. Only a few exceptions to this general rule are permissible, and only in cases where traditional techniques are quite clearly inadequate in order, for example, to protect against rain water (waterproofing of roofs) or from damp (stopping capillary action in walls) or against fire (flame retardant treatments) or biological agents (antiparasitic treatments). Old plasterwork must always be preserved, by filling and fixing and also by adding mortars of the same composition, where necessary. Paintwork must be touched up or if necessary renewed using traditional colourings. Wooden floors must be treated with natural protective coatings. Wood components must be preserved, as far as possible, and must only be replaced in exceptional cases, using seasoned woods of the same type. Floorings must be preserved and must never be replaced with new materials. Brickwork must be re-pointed using mortar of the same type as the original and avoiding the use of cement mortars, which spoil the appearance and have negative properties with regard to humidity.
Maintenance can be divided into:
ordinary maintenance, involving limited work, not requiring the replacement of structural components;
extraordinary maintenance, involving the re-arrangement of internal space and the replacement of structural components.
These distinctions must be borne in mind, both because of the different technical and financial commitment involved in the two types of work, and because they are subject to different authorisation systems. Under current town planning and building regulations, for ordinary maintenance it is sufficient to communicate the date on which work will start to the municipal authorities. For extraordinary maintenance, planning permission must be obtained from the municipal authorities. In both cases, if the monument is subject to restrictions, permission must be obtained from the Superintendency for Cultural Heritage and Landscape.