Abstract
It has been noted, in case of the apartments in collective form, the drainage noise from cleaning of toilet causes many problems in the basement and adjacent rooms, mainly hampering the pleasant housing environment. The problems are increasingly raised by civil complaints with the public offices. Therefore, if the drainage noise generates when wash out of toilet bowl is grasped how the characteristics change according to the sorts of drainpipe, it is considered that the establishment of an effective sound insulation countermeasure could be possible when a civil petition against the drainage noise of apartment house is submitted hereafter. On such viewpoint, this study measured and analyzed the characteristics of drainage noise per the type of drainage pipe, according to KS A ISO $1996-1{\sim}3$, with the horizontal branch pipe and riser pipes in the drainage noise experiment chamber which has the characteristics of the anechoic room. In the result, the pipe type with excellent noise reduction function. The result of this study is considered to become available as fundamental data, to take actions on reduction of drainage noise of the ceiling piping method.