sm_jamieson wrote:
Most people replace cast iron pipes with plastic. Advantages, less
chance of freezing etc.
When my extension is built, I will have a soil pipe boxed in in the
kitchen and wish it to be as quiet as possible, so am considering new
cast iron for at least the indoor section. Anyone fitted new cast iron
? What are the standard sizes, best places to purchase etc. ?
And will it in reality decrease house saleability, since due to
ignorance, many poeple think all old cast iron needs to be replaced
with plastic (like they do with wooden windows) ?
Simon.

There are better ways to get sound reduction that cast iron. Its very
hard to work with and probably rusts faster than plastic.

I'd use plastic and then cast concrete around it. Cast iron is NOT
quiet. Another possibility is to box in with blockwork, filling the
space between with expanding foam. The foam will asborb high frequencies
and the blocks the lower.