The feasibility to manufacture a 3D warp interlock preform from 1000 Tex flax roving is investigated by means of a prototype machine developed to GEMTEX laboratory. The provided flax roving has low tensile failure load because of lack of twist so it isn’t suitable for weaving. The first step was dedicated to improve the tensile properties of the roving through twisting process and identifies the optimal twist level. Experimental campaign is conducted by applying different twist level and evaluates the roving tensile properties. The ultimate tensile load increases as roving twist level increases until a threshold at which the tensile load declines as twist level increases. While the failure strain increases continuously as twist level increases. Five fabrics are produced with the same flax roving, 3D weave architecture and warp number and weft column number per unit length. Only the number of weft layers varies. The physical and tensile properties of these five flax fabrics are characterized experimentally. A considerable effect on the thickness and areal density of the fabric is reported. The difference in the waviness length between the two types of the warp roving (reinforcing and binding) has a significant impact on the tensile behavior of the fabrics in warp direction through the appearance of two phases on the force-strain curve. Otherwise, the variation of the number of layers does not induce a remarkable impact of the fabric structure on the tensile performance of the constituting roving.