To prevent a flexible pipe for piping from struggling at the time of discharging water and to prevent a ceiling surface material from being given a large load at the time of charging water by connecting a water feeding piping and a header through a flexible pipe so as to easily position and move the header and a sprinkler head.

After arranging the water feeding piping 11, the header 15, a flexible pipe 21, the flexible pipe for piping 23 and an elbow 25 between a ceiling slab 1 and a ceiling base material 2, the ceiling surface material 3 is fixed to the material 2 directly or with a fixing metal fittings or the like. The header 15 and the elbow 25 are connected through the piping 23. Thereby, the installing place of the sprinkler head 27 is easily varied. In addition, as a branch pipe 12 and the header 15 are connected through the pipe 21, the header 15 and the elbow 25 (a sprinkler head 27) are easily positioned to make it possible to move the header 15 without varying the position of the pipe 12.