To provide a construction in which roof finishing material can be nailed without necessity taking care of the position of joint part of adjoining roof components, and the waterproof function of the joint part can be also sufficiently maintained.

On the joint part 11 of roof panels 5 as adjoining roof components, a pressure sensitive adhesive sheet 13 is arranged extending over these roof panels 5, in addition the pressure sensitive adhesive sheet 13 is covered with a waterproof sheet 14 as a plane-like member so as to form a roof backing plane 6, and a roof finishing material 7 is constructed on the roof backing plane 6 by nailing. Hereby, even if the joint part 11 is nailed, the waterproof function is maintained by the pressure sensitive adhesive sheet 13, and hence it is unnecessary to take care of the position of the joint part 11.