View Full Version : Water Draining Noise Thru The House
10-30-2004, 09:02 PM
We have recently moved into a new two floor home in Southern California. When any of the upstairs bath tubs drain, toilets flush, or upstairs washing machine drains the noise radiates through the entire house. The walls that the cast iron pipes are in are 6-10 inches thick. The cast iron goes down to the basement and then changes to black "plastic" piping.
The noise is apparent as the water slopes horizontally, and becomes very loud just as it turns the 90 degree to start dropping from the second floor down.
My understanding is that cast iron pipe is the "quietest".....so what can be done to eliminate/correct or at least insulate our "waterfall" sound effects?
10-31-2004, 05:46 AM
I believe the old idea that cast iron is quiet is a myth. There are valid reasons to use it, but ABS may be quieter.
You said the wet wall is 6 to 10 inches thick. Is there any insulation in that wall?
I don't have any ideas except to try to insulate. If you can locate the pipe exactly, you could use some blown-in insulation by making only 2 or 3 small holes.. I do not recommend any type of expanding foam, because even the so-called minimal-expansion type could bow the drywall.
Any place the pipe touches framing, either studs or plates, the sound and vibration transfers, and the framing resonates. I don't know any way to fix that/
This is a common problem. CHeck with your builder. Check with your neighbors. CHeck with some good local plumbers. There are lots of people out there with cumulative experience in the hundreds of years, so there might be a solution somewhere.
I, personally, have found that cast iron is the quietest and have several times removed ABS and replaced with cast iron when the original plumber did not plumb the drops in cast--the difference was always amazing. In fact, I believe that PVC DWV is also quieter than ABS.
I have to say that I have never run into noise like that from cast iron, and other than insulation as Jimbo has suggested, I have no other ideas either. I would encourage you to call your builder. Are his other houses like this?
11-01-2004, 03:18 PM
I've read of some plumbers that put a small jog or offset in the pipe's veritical section to slow the rapid drop. Think of a 2-3 story waterfall - the falling water doesn't make much noise, but when it hits, it does! Some stacks could be several stories tall, and if straight, the stuff can really accellerate to a high velocity. When it eventually does need to turn, it hits that junction pretty hard. No practical experience on this...
11-02-2004, 08:13 PM
Jim surprises me with his position on cast iron not being quieter. I have cured (or thought I did) customers noise problems by replacing plastic with cast iron. I do put in a couple of forty-fives. However since this noise radiates throughout the house I think it is more likely framing to pipe contact.
I'm also surprised that the sound of water could bother a sailor, Sam.
11-03-2004, 06:18 AM
There are lots of variables here, and I was just commenting based on my admittedly limited experience. I do agree that noise transmission to the framing system is a big culprit, so installation technique may be as important as the material used.