FORMWORK FOR CONCRETING PREFABRICATED STAIRS AND METHOD FOR ITS MANUFACTURE

The invention relates to a cardboard formwork (100) for concreting a prefabricated stair (140), wherein concrete is being poured into the cardboard formwork (100) during concreting, and wherein the cardboard formwork (100) is constructed by folding and/or assembling one or more cardboard elements (110), and the one or more cardboard elements (110) are cut with predetermined cuts (120) and/or cutouts (130), and wherein the assembled cardboard element(s) (110) facing the concrete constitute a substantial part of the formwork (100), the formwork (100) being capable of supporting the prefabricated stair (140) during the process of concreting said stair (140).