Tire comprising a crown reinforcement

A tire with a radial carcass reinforcement, comprising at least one layer of reinforcing elements, the tire comprising a crown reinforcement formed of at least two working crown layers of reinforcing elements which are crossed from one layer to the other making with the circumferential direction angles of between 10° and 45° and the ends of which are radially uncoupled by a polymer compound, which layer is itself capped radially by a tread, the tread being connected to two beads via two sidewalls, wherein the reinforcing elements of at least one working crown layer are metal cords with saturated layers, at least one internal layer being sheathed with a layer consisting of a polymer composition and wherein, in each of the shoulders of the tire, at least the uncoupling polymer compound in contact with the ends of at least two working crown layers exhibits, in the sorption test, a gas content lower than 0.06 m3STP/m3ML.