Complex Assessment of Roof Structures

AbstractThe structural analysis of a complex roofing system – the early XX-th century Stock Exchange in Timisoara – has brought forward a paradoxical situation: this early modern building displayed an amazing collage of various traditional typologies of timber roofing, connected in order to produce a spectacular aesthetic effect of roof line. Further studies of XVIII-th, XIX-th and early XX-th century roofing structures presented an interesting evolution: until mid XIX-th century the roofs were produced by craft guilds, influenced not only by their practical knowledge but also by symbolic and traditional knowledge manifested in the choice of peculiar geometric traces (sacred geometries) not unlike the famous Chinese roofing principles, described in “Yingzao Fashi” manual. Starting with the end of the XIX-th century, the guild system vanished along with the symbolic and traditional meanings, leaving the practical knowledge completely independent – ready to be used for spectacular and aesthetic purposes (as in Art Nouveau and Secession buildings). Well into the XX-th century, even that knowledge vanished, leaving a simplified, standardized and efficient form of roof framing.Paradoxically, well into the mid XX-th century, an unconventional thinker, Buckminster Fuller, was able to generate a new kind of “roofing system”, the “geodesic dome” and the space frame structure, taking inspiration from the same kind of holistic and universal approach which animated the old craftsmen. Our investigations highlighted the overwhelming importance of a holistic and symbolic world view (“weltanschaung”) in the making of such specialized structures as the roofing frames, at least until the mid XIX-th century. A complex assessment of such structures must take into consideration these elements in order to fully understand and properly conserve and restore them for the benefit of further generations