PURPOSE: To make it possible to provide a sure seal with ease even under such conditions that workers are prevented from getting into the outside of an outer wall.

CONSTITUTION: A siding joint 1 is provided, in which a belt-shaped press member 11 for contact with the outside area of butting parts 5 of siding groups 4a, 4b applied to the outside of wall panels 2a, 2b is provided. By the traction and fixing from the indoor side through the wall panel butting surfaces 6 approximately aligned with the position where the joint 1 is placed, the siding butting parts 5 are pressed and fixed in watertight manner. The siding joint 1 used in this joint comprises the press member 11, a caulking agent layer 12 laid over one surface of the member 11, and a plurality of tensile members 13 disposed on said surface.