The present invention relates to a constructing method of a waterproof and root barrier structure which can secure continuity of root barrier characteristics at connected parts by securing continuity of a PET film used to integrated type waterproof and root barrier sheets even at the connected parts where the sheets come into contact with each other and are connected to each other, thereby enhancing adhesive strength of the connected parts through a triple-decker structure using a punched joint root barrier stiffener. The constructing method of the water proof and root barrier structure according to the present invention comprises the steps of: coating the concrete surface with primer to form a primer layer bonding integrated type waterproof and root barrier sheets, which have a waterproof function, a root barrier function and a self-adhesion function, on the upper part of the primer layer in a state where the end parts of the sheets are spaced apart at a predetermined interval forming a connected part between the adhered sheets coating synthetic resin onto the upper part of the entire surface of the waterproof and root barrier layer after the connected parts are formed. In the connected part forming step, after high hard urethane or FRP is charged between the sheets which are spaced apart from each other at a predetermined interval, joint root barrier stiffeners are bonded on the sheets in such a way that both ends are respectively located on the sheets located on both sides, the upper parts of the joint root barrier stiffeners are coated with high hard urethane or FRP, and nonwoven fabric is bonded on the upper part and the lower part of a PET film, which is located in the middle of the joint root barrier stiffener, by a thermosetting resin adhesive agent, and then, punched holes are formed in the edges of both sides of the joint root barrier stiffener at regular intervals in the longitudinal direction.COPYRIGHT KIPO 2014본 발명은 방수·방근 일체형 시트가 맞닿아 이어지는 접합부에서도 시트에 사용된
