---

This paper presents an inspection and diagnosis system customized for rendered walls, both interior and external. It classifies all anomalies capable of affecting renderings and most of the likeliest corresponding causes and is supplemented by anomaly-cause and inter-anomaly correlation matrices. In addition, the diagnosis, repair and maintenance techniques suitable for these anomalies are classified. Examples of the files that contain the exhaustive characterization of the anomalies and diagnosis, repair and maintenance techniques are also presented. The system is the result of an intense literature review, which allowed collecting and organizing the information available on pathology of renders. Next it was validated by mathematical manipulation of the data collected from standard inspections of 55 buildings, in which 150 renderings (100 exterior and 50 interior) were examined. The system proposed may be included in a proactive maintenance strategy, since it is robust, reliable and has been statistically validated. The systematic structure of this system is innovative and can help the inspector by making his/her work more objective and standardizing procedures. Anomalies in wall renderings may be prevented/minimized if buildings are properly managed by developing and implementing proactive maintenance plans that cover the following areas: technology (adequate maintenance and repair solutions, including the selection of materials and execution techniques), economy (minimizing running costs) and functionality (appropriate use).