Method for manufacturing a composite product comprising: - folding a first layer in order to create a first folded layer consisting of a first and a second superposed portions (30A, 30B) extending from a respective first and second free end (3A, 3B) to a first bend, - folding a second layer in order to create a second folded layer consisting of a third and a fourth superposed portions (40A, 40B) extending from a respective third and fourth free end (4A, 4B) to a second bend, - laying the first folded layer over a first support surface with the first portion in contact with the first support surface, - laying the second folded layer over the first folded layer with the third portion in contact with the second portion of the first folded layer, the first and second folded layers (3, 4) being oriented with respect to each other in order to extend from a first side including the first, second, third and fourth free ends (3A, 3B, 4A, 4B) to a second side including the first and second bend (3C, 4C), - laying a plurality of fibre layers over the second folded layer and a cover surface over the plurality of fibre layers, - moving the assembly comprising the first and second folded layers (3, 4), the plurality of fibre layers and the cover surface over a second support surface with the first portion in contact with the second support surface, - pulling the second free end of the first folded layer and the third free end of the second folded layer in order to extract the first and second folded layers (3, 4) from between the fibre layers and the second support surface in order to let the fibre layers and the second support surface to contact each other. - folding a first layer in order to create a first folded layer consisting of a first and a second superposed portions (30A, 30B) extending from a respective first and second free end (3A, 3B) to a first bend, - folding a second layer in order to create a second folded layer consisting of a third and a fourth superposed portions (40A, 40B) extending from a respective third and fourth free end (4A, 4B) to a second bend, - laying the first folded layer over a first support surface with the first portion in contact with the first support surface, - laying the second folded layer over the first folded layer with the third portion in contact with the second portion of the first folded layer, the first and second folded layers (3, 4) being oriented with respect to each other in order to extend from a first side including the first, second, third and fourth free ends (3A, 3B, 4A, 4B) to a second side including the first and second bend (3C, 4C), - laying a plurality of fibre layers over the second folded layer and a cover surface over the plurality of fibre layers, - moving the assembly comprising the first and second folded layers (3, 4), the plurality of fibre layers and the cover surface over a second support surface with the first portion in contact with the second support surface, - pulling the second free end of the first folded layer and the third free end of the second folded layer in order to extract the first and second folded layers (3, 4) from between the fibre layers and the second support surface in order to let the fibre layers and the second support surface to contact each other.