Construction process for groove of crenelated parapet wall

The invention discloses a construction process for a groove of a crenelated parapet wall. The construction process comprises the following steps that when a crenelated parapet wall formwork is bound on a shop roof, a square timber is placed on the portion, 50 cm above the ground, of the inner side of the formwork, so that the groove can be easily formed in the crenelated parapet wall; after the formwork is bound for a week, the crenelated parapet wall formwork is dismantled, the groove is formed in the portion where the square timber makes contact with the crenelated parapet wall, and then a first layer of waterproof roll is laid and fixed into the groove; a second layer of waterproof roll is laid on the first layer of waterproof roll and fixed into the groove; and the ready-made second layer of waterproof roll is subjected to crenelated parapet wall coping painting, and the groove is painted to be flat so that the waterproof rolls can be pressed into the groove. According to the construction process, the wat