Storie di legamenti. Assetti e problemi conservativi di sistemi di connessione tradizionali

Traditional connections between floors or stone cladding and walls are often made of metal bars and tie-rods, which are nailed into the wood or cemented into the stone-brickwork. The so-called "legamenti" (links) are an essential part of the constructive culture in Venice, where the building system is based on diffused joints between thin structures, rather than on massive walls, because of the site peculiarities, first of all the unreliability of the ground. Documentary evidence is provided of this one as an historical feature in Venice, which gave rise to such complex devices as the "fiube", chich build up a kind of gear made of different materials, connecting stone and iron with wood and brickwork; fiube can only be reinforced (not replaced or repaired) by adding tie rods. Even in other, and less peculiar places, wood-towood or wood-to-masonry ties are often made of iron, sometimes carrying out some interesting and refined connections, as a metal device of a rural roof in Lombardy turns out to be. This paper tries to compare the results of different researches and experiences in restoration, focusing on both urban and rural contructive contexts, describing the different layouts and peculiarities but also some common problems, above all the decay by oxidation. Whoe damages are both physical and structural, introducing the preservative topic of adding modern interventions, as a support of traditional devices, rather than simply replacing them.