The ornamental design for a buttjointflashingsheet, as shown and described.
FIG. 1 is a front, top, right side isometric view of a butt joint flashing sheet showing my new design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a left side elevation view thereof;
FIG. 5 is a right side elevation view thereof;
FIG. 6 is a front elevation view thereof; and,
FIG. 7 is a rear elevation view thereof.
The broken lines shown in the figures are included for the purpose of illustrating portions of the butt joint flashing sheet that form no part of the claimed design.
Sheet metal flashing member for frame structures of roof windows or similar roof penetrating building structures and a flashing frame comprising such a member