To easily and certainly repair existing corrugated slate installed to a roof or an exterior wall.

A saddle 38, which comprises a flat surface 36 having a through hole 36a and skirt portions 40, 40 separated and extended downward from the flat surface, is placed on existing corrugated slate 18. External thread 10a of a hook bolt 10 projected from a ridge portion 18a of the corrugated slate 18 is inserted into the through hole 36a and the skirt portions 40, 40 are laid across the ridge portion 18a. A self-tapping nut 42 is interlocked with the external thread 10a projected from the through hole 36a, and the saddle 38 is fixed to the top of the ridge portion 18a. A channel member 44 is installed to the top of the saddle 38 and they are fixed together by a tapping screw 50. Moreover, a metal roofing member 30 is arranged to the top of the channel member 44, and tapping screws 56 are screwed in the channel member 44 through the metal roofing member 30.