When sites are discovered and excavated, the decorated walls of sculpted shelters are subjected to the action of natural physico-chemical and/or biological agents, as well as to human vandalism.
The site of Chaire-à-Calvin (property of the département of Charente), is protected by Lippi fencing, whereas Cap Blanc (which is government property, managed by the Centre des Monuments Nationaux) Reverdit (private property) and Roc-aux-Sorciers (government-owned) are protected by a roof and/or a wall. In addition to providing physical protection against possible vandalism, roofing helps mitigate thermal swings and protects the wall against direct sunlight and water runoff that can result in loss of material from the decorated walls.
The presence of the owners themselves (Reverdit), guides (Cap Blanc) and responsible individuals (Roc-aux-Sorciers, Chaire-à-Calvin) makes it possible to control and guide visitors as well as constantly monitor a site's state of preservation: visual inspection can reveal variations on the walls, such as mineral or organic appearances or loss. Supervisory staff also perform routine site maintenance.
More in-depth surveillance is usually carried out. Climatic and biological monitoring provide indicators of the site's stability, particularly if it is open to the public. These include temperature increases, changes in relative humidity and fluctuations in internal biological pollution. These readings are used to trigger appropriate actions, such as treatments to be applied (Reverdit) or work to be carried out (Chaire-à-Calvin). Monitoring of the sites' surrounding environment (agriculture, urban planning, roadworks, etc.) is also vital because these shelters are open environments in constant contact with their karstic context and the landscape (water runoff, fracturing, vegetation, etc.).
Finally, all development work for the purpose of enhancing the site or making it available to the public is subject to strict specifications that must specify:
- The nature of the materials to be used in order to ensure their harmlessness
- How the works will be performed and how their impact will be monitored
Thus, although a few years ago, as part of efforts to highlight a site, casts could be made (Roc-aux-Sorciers), today's 3D topographic digital recording techniques means that direct impact to walls can be avoided (Chaire-à-Calvin).