A method for producing a gypsum board (GB) used in the building sector, comprising the steps of: (a) producing a glass-fibre mat by (i) feeding a glass-fibre layer made of combining glass-fibres from a roller (R2), (ii) feeding a reinforcement element from another roller (R1), (iii) contacting said glass-fibre layer and said reinforcement element over a moving cylinder (C) and coating by a filling liquid the contacted said glass-fibre layer and said reinforcement element on the moving cylinder (C) located inside a filling fluid tank (ST), (iv) scraping excess filling liquid that is puddled onto the glass-fibre layer and the reinforcement element over the glass-fibre layer and the reinforcement element after the coating process and transmitting the excess filling liquid back to the filling fluid tank (ST), and (v) drying the produced glass-fibre mat comprising a filling layer which increases strength properties of the glass-fibre layer and the reinforcement element which is located between the glass-fibre layer and the filling layer and provides a massive increase in strength to form a final product after drying; and (b) coating said glass-fibre mat thus produced on both sides of gypsum (G) to form said gypsum board (GB), said reinforcement element being any material that is synthetic, can be woven, strength enhancing, portable and flexible such as polypropylene, glass-fibre, carbon-fibre. (a) producing a glass-fibre mat by (i) feeding a glass-fibre layer made of combining glass-fibres from a roller (R2), (ii) feeding a reinforcement element from another roller (R1), (iii) contacting said glass-fibre layer and said reinforcement element over a moving cylinder (C) and coating by a filling liquid the contacted said glass-fibre layer and said reinforcement element on the moving cylinder (C) located inside a filling fluid tank (ST), (iv) scraping excess filling liquid that is puddled onto the glass-fibre layer and the reinforcement element over the glass-fibre layer and the reinforcement element after the coating process and transmitting the excess filling liquid back to the filling fluid tank (ST), and (v) drying the produced glass-fibre mat comprising a filling layer which increases strength properties of the glass-fibre layer and the reinforcement element which is located between the glass-fibre layer and the filling layer and provides a massive increase in strength to form a final product after drying; and (i) feeding a glass-fibre layer made of combining glass-fibres from a roller (R2), (ii) feeding a reinforcement element from another roller (R1), (iii) contacting said glass-fibre layer and said reinforcement element over a moving cylinder (C) and coating by a filling liquid the contacted said glass-fibre layer and said reinforcement element on the moving cylinder (C) located inside a filling fluid tank (ST), (iv) scraping excess filling liquid that is puddled onto the glass-fibre layer and the reinforcement element over the glass-fibre layer and the reinforcement element after the coating process and transmitting the excess filling liquid back to the filling fluid tank (ST), and (v) drying the produced glass-fibre mat comprising a filling layer which increases strength properties of the glass-fibre layer and the reinforcement element which is located between the glass-fibre layer and the filling layer and provides a massive increase in strength to form a final product after drying; and (b) coating said glass-fibre mat thus produced on both sides of gypsum (G) to form said gypsum board (GB), said reinforcement element being any material that is synthetic, can be woven, strength enhancing, portable and flexible such as polypropylene, glass-fibre, carbon-fibre. <EOS>