To improve execution workability by forming multiple curved surface- shaped notches on one end side of a spacer member forming a corrugated lower face, and selectively using one of the notches according to a corrugated roof material at the time of execution.

The upper face 31 of a spacer member 3A molded with a foam resin to be kept in contact with the lower face of a coping material is formed into a plane shape, and the corrugated lower face 32 to be kept in contact with the corrugated face of a corrugated roof material 2 is formed into a corrugated face along a curved plate section 2a. Multiple curved surface-shaped notches 32a1 are formed on one end side of the corrugated lower face 32 at intervals in the lateral direction so that an optional notch can be selected and separated by hand. At the time of execution, the notch 32a1 corresponding to the curved plate section 2a of the cover side end edge of the corrugated roof material 2 is selected and separated. The curved face 32a along the curved pate section 2a of the cover side end edge can be simply and surely formed for the spacer member 3A. Waterproof performance can be secured.