The present work is devoted to represent a case study with the aim to give useful elements in order to evaluate the application of nanolime. Callixtus Catacombs have been the object of the research carried out in situ and in laboratory, checking indirectly in the short run and in the long run the porosity variation in the materials.
This work grows out from the need to develop consolidating treatments tailored for a specific archaeological structure  under hypogeal conditions .
Generically in a preventive conservation project, treatments and materials are always more frequently evaluated in order to provide two main requisites:highest durability, through the combination of complementary preventive activities, such as monitoring and adjusting environmental parameters and defining a monitoring and routine maintenance plan of the structures, together with graphic and photographic documentation, and the systematic data archiving, in order to easily compare the short-run and the long-run variations.
The deterioration phenomena are caused by microclimatic conditions and thermohygrometric exchanges between walls and the microclime and presence of light and visitors flow .
The combination of water, air, and light interaction with the artefacts structures activates several degradation processes, interesting the various degradation phenomena: cohesion, crumbling, pulverization, concretion and/or biological patina growth.
In order to verify the property of the samples to simulate natural porosity, the capillary absorption curves of the laboratory-made samples have been compared with those of true specimens.