Effect of misuse and lack of maintenance on a historical building

In 2007, a cooperation between different institutions realized a proposal for a rehabilitation design of a problematic central area in Sesto San Giovanni, a large town in the metropolitan hinterland of Milan. Between new modern buildings and new streets, built during the second half of 20th century, a portion of the ancient convent of St. Nicolao is still present, but its neglected structures are in bad conditions. In order to preserve this past-memory of the city, the municipality, together with other associations, is trying to find a new destination for the building. Investigation procedures were requested to control the condition of the surveyed structures of the convent. The complementary use of powder drilling, sonic, single and double flat jack tests, supported by a geometrical survey of the building, was useful to evaluate the characteristics of the survived load-bearing walls. Main problems were generated by the misuse of the building that, after being a convent, was used as a rural construction and recently as a garage: the original organization of inner rooms and floors was modified with the insertion of modern concrete floors and new openings, that usually were not respectful of the previous structures. The paper will present diagnostic investigation carried out on the building and the definition of its state of damage.