To prevent reinforcing bars from being pushed up by ready mixed concrete and shorten a placement time by fixing a down stop member with a roof slab reinforcing bar with a fixture and partitioning a beam formation space area and a roof formation space area with an ejection stop member.

A reinforcing bar 72 is placed in a wall surface formation space area 62 segmented with a form 80 while a deep reinforcing bar 72 is placed in a slope roof formation space 52 and roof slab reinforcing bars 53 are placed respectively. At first, high slump ready-mixed concrete is placed at a stroke from an opening area 63 into the wall surface formation space area 62. Then, a comb-shaped ejection stopper member 1 is provided along the border between the space area 71 and 52 while the top of the space area 71 is covered, thereby loading the down stop member 10 on the reinforcing bar 52 and fixing with a fixture 20 which is provided with a removable flange and a tapping screw. High slump ready-mixed concrete is placed at a stroke into the space area 71 covered with the members 1 and 10 from the side of eaves to a ridge area. Before the ready-mixed concrete is cured, the member 1 is removed while the ready-mixed concrete is placed in the space area 52 separately by several times while the crest is being leveled.