The utility model discloses a double-guide drainage structure for roof
external drainage, and relates to the technical field of
house building construction. According to the technical key points, the device comprises a first double-water-guide
assembly arranged at the junction of a roof structure and a
parapet wall, the first double-water-guide
assembly comprises a horizontal main water drainage
pipe, the horizontal main water drainage
pipe is installed on the
parapet wall in a penetrating mode, and the inner wall of the lower side of the horizontal main water drainage
pipe is flush with a protective
surface layer in the roof structure; a horizontal drainage
branch pipe is arranged under the horizontal main drainage pipe, and the lower side inner wall, located at one end of the inner side of the
parapet wall, of the horizontal drainage
branch pipe is aligned with the lower bottom of a heat preservation layer in the roof structure. The ends, located on the outer side of the parapet wall, of the horizontal drainage
branch pipe and the horizontal main drainage pipe are fixedly connected with a vertical outer drainage pipe. By means of the horizontal main water drainage pipe and the horizontal water drainage branch pipe in the first double-water-guide
assembly, accumulated water above a protective layer in the roof structure can be effectively drained, and when accumulated water exists in the roof structure, the accumulated water in the roof structure can be effectively drained.