This paper presents an innovative technology of timber floor whose function is both the replacement of horizontal elements in historical buildings, not subject to constraints of protection, and the utilization in new buildings. The new system responds to the market demand that requires high performance characteristics in terms of stiffness in the plane, correct transmission of the horizontal actions, lightness and low thicknesses. The floor at issue is composed of two plywood panels glued in the intrados and extrados to a moulded grid panel in GFRP with a single warping of glass fibres. We want here to present the stages of study, research and design, that helped define an element considerably rigid and at the same time lightweight, trying to contain the thickness of the section. Laboratory testing phase has highlighted the increase in stiffness and flexural limitation that the coupling of the moulded grid panel with plywood panels undergoes in the different configurations.