摘要 |
PROBLEM TO BE SOLVED: To provide a floor slab which can improve performance of insulating floor impact sound downstairs and is easy in construction.SOLUTION: A floor slab 1 comprises: a flat plate part 7; and projections 6 projecting from the upper surface 4 or lower surface 5 of the flat plate part 7 or from the upper and lower surfaces 4, 5 thereof, and the projections 6 are not directly connected to a beam. The projections 6 are installed so as to project from the upper surface 4 or lower surface 5 of the flat plate part 7 located below a corridor area 3 of a dwelling unit. The flat plate part 7 is designed to have a characteristic frequency capable of obtaining desired performance of insulating floor impact sound downstairs from a habitable room 8, and a ratio of the total weight of the projections 6 to the total weight of the floor slab 1 is determined so that a characteristic frequency of the floor slab 1 with the projections 6 is within a range capable of obtaining the desired performance of insulating floor impact sound downstairs from the habitable room 8. |