To solve a problem in conventional radiating pipe laying of a hot water floor heating base board wherein feeding is carried out by an automatic piping machine, and piping and fitting into a laying groove is carried out by a pressing mechanism, but there is a possibility that fit-in piping will be detached from the laying groove if feed driving is continued without a fixing means and a track error occurs.

The radiating pipe laying groove 11 is provided as an inverted tapered structure, and it is composed by forming it as a fitting pressurizing structure wherein a maximum pipe diameter side face part of the piping 2 to be laid is pressurized and fixed by a width diameter of a groove inner wall in a predetermined depth from an opening. It is composed such that the radiating piping fed and laid by the automatic piping machine is fit and fixed by pressing into the laying groove.