You can change it with PVS pipe they better at noise reduction in comparison to ABC and easier to work with but in any case, you have to open up the wall no matter what you use.

They also have soundproofing wrap for PVC/ABC pipes I heard some of them are very effective.

During my reno, I changed my pipes to cast iron, can’t hear a thing now. And I did it for the same reason as you, they were running through the dining room.

It was totally worth it doing it during the reno, I don’t know if I would do it after the fact, depends on cost I suppose.

@luscious111 @GN Builders L.L.C Since I will open up the walls, should I change the pipes PLUS soundproof wrap or that could end up being an overkill. How does PVC pipes compared to cast iron for noise reduction?

@GN Builders L.L.C,

Your post suggests you need to relearn your ABCs: It's PVC pipe and ABS pipe. Get the initials wrong in a polymer reaction and bad things can happen. If you'd prefer to forgo the initials, you can simply write out polyvinyl chloride pipe or acrylonitrile-butadiene-styrene pipe.

If you’re going to the effort of opening the walls, you’ll want cast iron as it’s much quieter. I didn’t insulate mine and don’t hear anything. Flush with the walls still open and you can decide.

@Charles Ross Homes Mistype, thanks for the correction...

@GN Builders L.L.C.,

Kinda like "rapture" vs. "rupture." Makes a difference.

@juliacali Just wrap the Black pipe they installed and flush the water before and after before closing up the wall and see if the sound is reduced, I'm sure it's not gonna be too much of a difference if you swap ABS for PVC.

As the pipes go, it's just the plumber's preferences...Some love working with Black Pipe, Some love PVC pipe and they all swear by it whatever they use... Nobody likes to work with Cast Iron pipes, they're more expensive, heavy as hell, harder to handle and install so unless someone is willing to contribute to their retirement plan they will suffer and use Cast Iron. :-)

Good luck

@Charles Ross Homes When you bored you can follow me around and fix things, I don't mind at all, I make lots of typoes, I might even throw you a bone if you do a good job. ;-)

@GN Builders,

Expert advice should be offered by experts with first-hand knowledge to contribute to the discussion. And yes, spelling counts. If you're confused about ABS vs. ABC and PVC vs. PVS what does that say to the average DIYer about expert advice on houzz.com?

@Charles Ross Homes the self-proclaimed "expert".

You would have to ask them if you don't have any common sense to figure out by now it was a mistype and move on to a different subject.

Right. Rapture vs. rupture.

You say you have insulation in the wall - are you sure? It would seem unusual to insulate an interior wall - presumably for sound - and then not do a cast iron downpipe. What I say unusual, you can substitute incompetent if you are feeling mad.

Your contractor suggested the ONLY way to reduce sound is to change to iron which is not true.

Maybe the most effective but not the only way.

If there is no fiberglass in the wall, you could try injecting foam which could be done through small access holes. Alternatively, or additionally, you could put another layer of drywall down with acoustic glue in between the two layers. If you have room, you could do even more.

No-hub cast iron will work but so will wrapping the pipes (or enclosing the structural bays) with Mass Loaded Vinyl or adding layers of drywall possibly on resilient channels. It depends on the situation. Are there recessed lights in the ceiling?

In my opinion... cast iron is the best option. We have insulated 4" pvc pipes and I can clearly hear the water running upstairs.

Which is not all bad. We moved into this house when my youngest was a senior in high school and my oldest a freshman in college, knowing who is up and in the shower has been more useful than I could have imagined.

Having said that, cast iron will work and isn't marketing hype. I am sure some pipe soundproofing works, but others are mostly hype. If you are going to be in the wall anyway go for cast iron and avoid the soundproofing options which are more expensive and less certain.

@res2architect Yes, I have recessed lighting.

Instead of changing out the pipe to cast iron you could just open up sections of the wall and spray that one bay with some closed cell foam. He will only have to open the bay up every foot or so just to get the foam in there and make sure it has a place to expand out of. It's obvious let the foam dry trim it off and seal up the wall. I'm assuming that you have half inch drywall on this dining room wall. Round a test and see how quiet it has gotten with the closed cell foam. If the noise still exists beyond your comfort level, fear not. You can always cover that one wall with another layer of 5/8 drywall. This is a common practice for soundproofing music rooms and alike. Seal, texture, paint, and I think you will be done. At the cost of cast iron pipe I believe that you can do the above repair for less.

@juliacali, I had same noise concern for our basement. We went with cast iron. Our builder said no prob, plumbers did a great job and price was reasonable. There are other options besides cast iron but that is irrelevant.

A contractor can easily retrofit this in a house.