Villa Tomati, a roof within the roof: a project to restore the past throughout knowledge

This paper aims at describing the diagnostic study on structural performance of the XV century wooden roof of Villa Tomati, located in Genoa, Italy. Several wooden roofs were analyzed with the purpose to obtain fundamental data in order to restore these ancient covers, which can be considered particularly valuable from the historic-artistic point of view. General principles regarding both Restoration and Diagnosis of structural performance were framed in International Charters (ICOMOS, 1995) (Venice Charter, 1964). In particular reference literature regarding diagnosis methods and grading of timber is represented by the European one (Ceccotti, Uzielli, 1989), (Giordano, 1993), (Bonamini, 1996). The structural performance analysis, which is based on the diagnostic study, is considered fundamental in order to define a restoration project based on minimum interventions (ICOMOS 1995). Structural performance will be performed by finite elements analysis using the packaging software STRAND 7. The final goal of the conservation project is to restore the structure bringing it back to the original state, preserving structural conception and roof typology. The work described shows the importance to perform a detailed diagnostic study prior to define the restoration intervention in order to be conscious of Conservation State of the structures. This is fundamental in defining an adequate restoration project, reaching the goal of operating minimum interventions and to maintain as much as possible of original materials while preserving original structural conception and typology. This paper describes the wooden roof typology found in this Villa and the diagnostic method applied for this study. A detailed analysis of the results of the diagnostic process will be discussed. The structural analysis approach chosen for the study of this complex carpentry will be presented and analyzed. Finally it will be possible to foresee possible directions regarding restoration project strategies.