New and old widened roof waterproof structure

The utility model relates to the field of house transformation, in particular to a new and old widening roof waterproof structure which comprises a new house wall body with a side wall parallel to an old house wall body. And a deformation joint is formed between the old house wall body and the new house wall body. The device further comprises a waterproof coiled material, a cover plate and a water guide assembly. The waterproof coiled material and the cover plate at least cover an old house parapet wall above an old house wall body, a new house parapet wall above a new house wall body and a deformation joint between the old house parapet wall and the new house parapet wall, and the cover plate covers the waterproof coiled material; the water guide assembly comprises a water receiving box fixedly connected in the deformation joint below the waterproof roll and a water falling branch pipe used for connecting the water receiving box and the water falling header pipe. The deformation joint of the structure can fr