On Jan 22, 9:46*pm, Niels L Ellegaard
wrote:
On Jan 22, 9:17*pm, Speedy Jim wrote:

A kink or offset can indeed produce a lot of noise with a fall
of 5 stories, especially if it is a 90 deg offset rather than 45 deg.

More important though is the pipe material. *Cast iron stacks
produce far less noise than PVC or ABS plastic piping. *What was used?

But it may not be the plumbers' fault. *Did they comply with the
job specs? * If so, the consulting engineer may be to blame.

Rather than redesign the piping, it may be practical to
apply soundproofing material, such as:http://soundproofing.org/sales/prices.html

Will the noise lessen as the pipes get used? *HaHaHaHa!

Thank you for the answer.

The pipes are made from metal, and the kink is only 45 degrees, but
the metal appears to be significantly thinner than the metal in the
pipe I had before. If I hit them with a metal object they sound a bit
like a bell. The previous pipe was also better attached to the wall,
so perhaps a part of the problem is lack of damping.

Anyway, I am not sure if there were detailed specs, and it is further
complicated by the fact that the house is owned by a cooperative
society, so if I want the pipes to be replaced I need to convince
other people complain on my behalf, and that may not be easy.

I will look into the sound proofing materials and see what I can find.

For the sake of google: They entrepreneur ended up building a wooden
box around the pipe. I talked to several people and in my country
wooden
boxes seem to the the standard approach to sound isolating this kind
of
sewer pipes. All the sound has gone, so I am happy.

Regarding sound isolating lead tape I was told that this tape could
only dampen the high frequency noise. So the deeper tones would
still be hearable through the tape. I haven't tested if this is true.

Thanks again for all the advice.

Niels