The invention relates to a tire comprising a crown reinforcement formed of at least two working crown layers of reinforcing elements the ends of which are radially uncoupled by a polymer compound. According to the invention, 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 such as a rubber composition and 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.