In this paper, we propose to study the building maintenance in ancient Rome, both in public and private context, through a comparison between legal norms and archaeological surveys. More specifically, we will focus on wall covering. Building maintenance is not a well-defined category in ancient Rome, and literary sources which help us understand it are very few. Legal texts, mainly from the Digest, offer more information, but in scattered pieces where building maintenance is just one subject among others. Thus, only confrontation between these texts and archaeological data really helps to understand how building maintenance was organised in the ancient Roman world. Remains of wall coverings are very interesting in this perspective, as they are the ultimate piece of a building and with no doubt the more easily altered by degradations due to day-today use of a building. We will try to propose a distinction between maintenance, repair and renovation. These different interventions are not defined in Latin by specific words but are the responsibility of different actors in terms of legal norms. We can be even more specific by studying different types of interventions on wall coverings and compare them with norms defined by Roman jurists. Finally we will turn back to the Roman way of defining maintenance by focusing on the definition of what can be called "well-maintained". Roof is the first criteria to define it; the second one are the walls. In both cases, the state of the decorations is cited by literary sources to describe well-maintained building, even if the place of the decoration in defining the identity of a building is a subject of controversy between Roman jurists. We will then conclude on a reflection on the link between maintenance and identity of a building, based on archaeological and legal criteria.