Abstract: Improved system ensuring the support and securing of long support beams of wood core plywood or composite materials (1A, 1B . . . ) on metal support posts (2B . . . ), characterized by the fact that each post is provided with at least one scaffolding strut (3B.sub.1, 3B.sub.2 . . . ) articulated at its lower end on a hinge pin (5.sub.1, 5.sub.2 . . . ), integral with the adjoining post, the upper end being provided with a receiving angle (6.sub.1, 6.sub.2 . . . ) which bears a corner piece (7.sub.1, 7.sub.2), integral with the end of a long supporting beam (1A, 1B . . . ) by means of contact pieces (8.sub.1, 8.sub.2 . . . ) fitted to said corner piece; the vertical reaction of the weight of the beam R.sub.v is thereby transferred, by the application of load to the scaffolding R.sub.p, to the axis of the integral strut (3 B.sub.1, 3B.sub.2), said load creating a horizontal load of longitudinal stress R.sub.H in the adjoining long supporting beam.