PURPOSE: To improve vibration-resistant capacity by a method wherein a bolt provided at the underside of a supporting plate is screw-fitted, being capable of moving up and down, to a nut of a post hardware erected on the surface of an independent footing and side-end parts of floor panels are placed over the surface of the plate.

CONSTITUTION: A strut hardware 3 is made from a base plate 16, cylindrical body 17 erected thereon and a nut 2 that is fixed at the top of the cylindrical body 17. The strut hardware 3 is then fixed to the surface of an independent footing 1. A bolt 5 provided at the underside of a supporting plate 4 is screw- fitted to the nut 2 of the post hardware 3. Height of the bolt 5 is adjusted by turning the plate 4 until the plate 4 fits at its surface against the underside of a floor panel 8. Side-end parts of the floor panels 8 are then placed over the plate 4 and a connecting hardware 9 is placed between the adjoining floor panels 8 and is fixed with bolts and nuts 20. Then the bolt 5 is made to penetrate through the connecting hardware 9 and the tip of the bolt is secured with a nut 6 of fixing metal 7.