The research focuses on hemp yarns activity in the woven reinforcements, depending on the production method as well as production of reinforcement of natural yarns and thermoplastic yarns as matrix in one woven product for production of composites of building materials. The reinforcements of hemp yarns (100 tex), polypropylene yarns (100 tex) and polyethylene yarn (220 tex) were produced using plain weaving technique on a craftsman’s loom. The measurement of fabric thickness and physical-mechanical properties of reinforcements were carried out according to ISO 5084:1996 and LVS EN ISO 13934-1-2001 standards. Fabric thickness of hemp yarns reinforcement was 0.61-0.69 mm and density 91-100 g/m2. Tensile strength of hemp reinforcement on warp direction are 241.7N-279.8N and on weft direction 249.4N -302.9N; tensile modulus 218.48MPa-271.24MPa and 189.3 MPa-196.1MPa. Laboratory Press LP_S_50/SASTM) was used for production of composites. The mechanical properties of composite were established according to ISO 527-5:2009 standard and thickness swelling in water was conducted in accordance to EN 622-2: 2004 standard. Composite thickness depending of reinforcement layers in composites was 0.34mm to1.1mm; the density of composites varied from 311 g/m2 to 1040 g/m.2 Tensile strength of composites varied from 303.09N (one layer) to 2019.39N (five layers) and the elastic modulus of same composites are 908.24MPa and 1809.64 MPa.