[QUOTE] So the idea, Why can't the drainpipe manufacturers make drainpipes that have a 'screw' type internal(sort of helter skelter) so the water would run down the spiral hence making no sound as it exited the bottom. I call this 'The Quiet Drainpipe' So there you go, first one to the Patent Office gets it. I will take my pleasure from seeing it the marketing success that it will most certainly be.[/QUOTE] One possible stumbling block (which we often hit in the office when designing drainage). With the screw formation, there will be a maximum rate of flow for the water going down the pipe. In a torrential rain, it might not be quick enough and you'd end up with it backing up. Often, a slight kink at the top would be enough to cause the water to swirl down the sides on the inside of the pipe, so it doesn't fall all the way to the bottom in a straight line. :)