PURPOSE: To easily and surely lay down a roof member on a parapet on the inside of a building so as to be sloped with a down-grade, without requiring the working of a sloped surface on the upper surfaces of the members such as adjusting members and verge-board fitting members.

CONSTITUTION: A connecting member 13 whose undersurface is horizontal and whose upper surface is sloped on the down-grade to the inside of a building is provided on the upper surface of a parapet 2, and a roof member 3 is laid down on the upper surface of the connecting member 13 along the sloped direction of the upper surface, thereby the roof member 3 is laid down on the parapet 2 so as to be sloped on the down-grade to the inside of a building. Only by working the upper surface of the connecting member 13 into a sloped surface, the need of slope surface working of the upper surfaces of the other adjusting members 14, verge-board fitting members 15, or the like can be dispensed with.