The invention relates to a tire having a radial carcass reinforcement, consisting of at least one layer of metal reinforcing elements, said tire including a top reinforcement, which is covered radially with a tread, said tread being joined to two beads via two sidewalls. According to the invention, the reinforcing elements of at least one carcass reinforcement layer are metal cables which, in the so-called permeability test, have a flow rate less than 20 cm3/mn and at least 10% of said metal cables are banded by a strand consisting of multifilament textile fibers.