Spruce Timber Trusses of Existing Pitched Roofs: a Reinforcement Study

A load-bearing timber truss of an existing pitched roof, located in Northern Italy, is examined in this paper by means of finite element analysis, with two possible configurations: the first one, without any reinforcement, that provides, given the assigned loads, barely allowable stress values in terms of current safety standards; the second one, with the application of fiber-reinforced polymeric fabrics on the bottom edge of the rafters and the tie beam, which results in a substantial reduction both in stress and strain. In particular, it is possible to observe a stress migration from the wooden material to the fabric, which is able to produce more satisfactory stress values within the entire structure, thanks to the exploitation of the tensile strength granted by the reinforcement.