Acoustic treatment for exposed pipes?

[Flyover]

Even without being painted yet I love the aesthetic of my exposed office ceiling. Sometimes I just stare at the ducts and pipes and wires and joists and subfloor and it makes me really happy.

However, one issue is that the drains from both full bathrooms originate from directly overhead. Needless to say, if anyone flushes the toilet or takes a shower during my morning meetings it is quite loud and distracting. I'm actually pretty used to it by now, to the point where it doesn't bother me, but I know one day I won't be the only one using this office, and others will surely complain. If you're not expecting it it really does sound like the water is being dumped right on your head.

The drain pipes are ~2" PVC. Is there anything I can maybe wrap the pipes in, or do something else, to make them quieter?

 

[Snoonyb]

Your's is an example why drain and waste lines in commercial buildings are cast-iron.

 

[Flyover]

@Snoonyb That's interesting. But, I'm not replacing my drains with cast-iron.

 

[user 4883]

Your's is an example why drain and waste lines in commercial buildings are cast-iron.

Not exactly. Cast iron pipes are definitely quitter but, the reason they are used in commercial builds is that they are against code. PVC emits toxic fumes when on fire and therefore are not allowed in a commercial building. Why the same does not apply to residential is beyond me.
So the solution would be to change out your pipes with cast (yea I know, not gonna happen).

 

[Flyover]

Many (most?) homes these days use PVC, yet I don't hear every home owner with living space below a bathroom complaining about the noise. I'm guessing finished ceilings dampen sound a lot, presumably by positioning relatively heavy material (sheetrock) between the pipes and residents' ears.

While I am opposed to reinstalling the drop ceiling, I don't have a huge problem with hanging a few acoustic panels (like this, or maybe the foam ones if I can find them cheap), attached to 1/2" OSB or plywood backers, from chains a few inches below the joists in strategic locations. This would preserve most of the view to the exposed ceiling and also the industrial look. I could eventually paint them to match the painted ceiling, whenever that happens.

Do you think that would work?

 

[Snoonyb]

If you place a value on your time, almost anything you attempt will either equal, time and material, or surpass the cost in cast-iron, as well as being aesthetically, less appealing.

It's your space to define.

 

[Flyover]

Time and effort are plentiful; if this particular project drags on for years that's fine. (Decades maybe not.) I believe for the acoustic panel idea I can craftily control costs very well: if it got up around the equivalent cost of cast iron pipes (plus paying a plumber to properly do the replacement because I believe that is beyond what I trust myself to do well) then I would be very, very surprised. The remaining question is whether it would be effective.

 

[Fireguy5674]

Whatever you choose to do toward sound proofing be careful of introducing a lot of highly flammable material into the space. Exposed foam will produce large amounts of very toxic smoke if a fire should occur. Escaping from a normal basement requires you to pass through the hottest and heaviest smoke at ceiling level to get out. Try to choose nonflammable materials as much as possible in your sound proofing plan.

Just a suggestion from a guy who was a firefighter for 30 years. Having seen and read about the the results of building fire traps, always makes me very cautious about material used.

 

[Flyover]

Thanks, @Fireguy5674 that is really great info and I will keep it in mind. Especially since the pipes in question are already PVC which isn't exactly lung-friendly when on fire.

 

[Sparky617]

My vertical pipes are cast iron, everything else is PVC, it does make them quieter. You could replace the offending section with cast iron and join it to the PVC with these. https://www.lowes.com/pd/Fernco-4-in-x-4-in-x-4-58-in-dia-Coupling-PVC-Fitting/1000075325 If there is a long section without fittings replacing it with cast iron wouldn't be a terribly difficult job. If there are a lot of fittings it becomes more involved.

 

[Sparky617]

Whatever you choose to do toward sound proofing be careful of introducing a lot of highly flammable material into the space. Exposed foam will produce large amounts of very toxic smoke if a fire should occur. Escaping from a normal basement requires you to pass through the hottest and heaviest smoke at ceiling level to get out. Try to choose nonflammable materials as much as possible in your sound proofing plan.

Just a suggestion from a guy who was a firefighter for 30 years. Having seen and read about the the results of building fire traps, always makes me very cautious about material used.

Most exposed residential plumbing is in basements or crawlspaces. The stuff behind walls is behind drywall with has a 30 minute fire rating. When a house is on fire the first thing to do is get the heck out. The toxic fumes from the PVC is just part of the mix of stuff you don't want in your lungs. Just regular smoke inhalation from burning furniture, carpet, household goods, wood, etc is enough to kill you. Fire fighters have air tanks when they go into a burning building.

 

[Flyover]

My vertical pipes are cast iron, everything else is PVC, it does make them quieter. You could replace the offending section with cast iron and join it to the PVC with these. https://www.lowes.com/pd/Fernco-4-in-x-4-in-x-4-58-in-dia-Coupling-PVC-Fitting/1000075325 If there is a long section without fittings replacing it with cast iron wouldn't be a terribly difficult job. If there are a lot of fittings it becomes more involved.

Yeah, it's all p-traps, elbows and tees as far as the eye can see...

 

[Eddie_T]

Yeah, it's all p-traps, elbows and tees as far as the eye can see...

I just had to say this. When I worked on the Kings Bay Sub Base expansion we had a labor relations guy in our group. I overheard a conversation with a laborer where our rep asked him what his job was. He told him that he installed P-traps our guy was taking notes and asked him if they were on the urinals. The laborer didn't laugh and said yes and also on sinks, and showers.

 

[Graybeard]

I believe there is a vinyl or rubber wrap to help with reverberation and sound. Not sure about combustibility, but it might be something to look into.

 

[Flyover]

Yeah I figure the noise happens because of the relative thinness of the pipe walls, allowing them to act like drum heads when water flows over them. Packing mass around the pipes is probably the name of the game, same reason why cast-iron is quieter.

 

[Bob Reynolds]

I believe you have some good advice here.

When we were build two story homes, we always use cast iron pipe for the vertical areas coming from upstairs.

As someone said, you just replace the vertical part (about 8-10 feet depending upon your ceiling height). Then you wrap the cast iron pipe with fiberglass insulation to help dampen the sound.

This should not be a major expense. The few hundred dollars you spend doing this will result in you being able to comfortably use your office space for many years to come.

 

[Flyover]

@Bob Reynolds Thanks for the advice, but the pipes in my office ceiling are almost entirely, as I noted, elbows and tees, with a few shorter (<6 ft, mostly <4 ft) horizontal sections. Anything vertical is off to the side in the wall and the noise from that isn't a lot. The splashing noises are from toilet flushes and running the sink and shower, presumably mainly when the waste water hits the p-traps.

 

[sadavis80]

I have a 'decently loud' water splatter in my basement from the toilet & shower above. My first thought was that the noise could be reduced by about 100% by simply rearranging the vertical pipes to be at an ANGLE... say 30-40 degrees off vertical. Wouldn't that stop most of the noises? Of course, my 'solution ' is a bit more complicated since the pipes are IN THE WALL instead of exposed!.
Steve

 

[ctviggen]

You can get heavy wrap for this, but it's expensive, and since it's heavy, you typically need to get it locally. I have a poorly built and designed house with a PVC pipe running from the upstairs bathroom through the wall to the basement. I'd have LOVED if this was cast iron. (If you watch This Old House, they often install cast iron in certain locations for this purpose.)

We have to do some drywall work in the room where this pipe runs. So, I was thinking of cutting the drywall where the pipe is and putting something around the pipe. Maybe the sound barriers here:

https://acousticalsolutions.com/product-category/sound-barriers/
I think it would be tough to replace the PVC inside the wall with cast iron, though I could be (often am) wrong. I'd pop the drywall back on and patch with the other patching in that room (had overhead lights installed, which meant they cut long parts of drywall out of the ceiling).

Since your runs are horizontal, with traps, that adds a whole layer more complexity.

If you go here: AVS forum Dedicated Home Theater Design, I'm sure someone has done something like what you want to do. Just be ready for a shock as to the amount of cost.