This study represents compilation of the results of experimental examinations regarding methods for improving the performance of floor impact sound insulation for heavy impact source in light-weight steel frame ALC-type dwellings. The primary factors examined include the number of steel beams and mounting method, ALC plate joint treatment method, sound-insulating ceiling specifications and vibration isolating support method of walls of room below, and we verified the effects of each through vibration tests. We thereupon measured floor impact sound for specific floor structures taking these verification results into account and stipulated cross-sectional specifications for the floor, ceiling and lower-floor walls with the performance of floor impact sound insulation for heavy impact source in the range of L_H-65-L_H45.
