Sound Insulation

[John]

I'm redoing our basement (or rather doing it...). While working down there, someone above flushed a toilet, and I was a bit dismayed as to the volume of splashing sounds I got coming down the main drain pipe. Lovely... The pipe is in the center of the room, and I'm building a column around it (with an access panel in case...). Before I drywall it, I'd like to take some measures to dampen the sound from the pipe. Is there a simple, fast way to do this? Is there any material I can buy for this?

On another, similar note, I have a finished wall upstairs on which the TV is hung. It appears as though the sound is carrying through the finished wall into the staircase, and down. Is there anything I can spray into the wall to dampen that? Again, I'm not looking for complete soundproofing, just to lower the decibel level a bit. In this case though, I'd prefer not to remove the existing drywall (not completely at least).

Thanks in advance

John

[Jon Danniken]

Wrap a few layers of 30# roofing felt around it, then find something pretty to put on top of that.

Jon

[aemeijers]

Plastic or copper, I presume? One of the few advantages of the old-style cast-iron waste stacks is that they radiate a lot less noise. It wouldn't be practical to switch it out, I'm sure, so the only idea I have to offer is a slab-to-floor enclosure of foam slabs or fiberglass batts, with a wood skin that you can non-destructively remove when needed. Mebbe 2 L-shaped sides that fit into slots on each other, held together with a few discreet screws, or even some industrial velcro? Unless the column you are building is huge, a simple access panel won't give much access for any major work on the pipe- we have lotsa pipes in the columns at work (computer and office floors in an 80 YO building), and when they have to work on one, they end up having to rerock half the column, in most cases.

[Sonny]

Theaters dampen sound with curtains and/or cloth covered walls. High end homes have cloth covered walls in the entertainment room(s).

Wrap a few layers of thick cloth (remnant store surplus or discounted fabric) around the pipe.

Decorate the wall, or part of, behind your TV with thick fabric, or a curtian if that decor is appropriate.

Sonny

[HeyBub]

Sound is transmitted two ways: The thing making the sound radiates the sound into the nearby environment. Insulation or baffling can control this. The other ways if for the source of the sound to vibrate a fixed object which in turn projects the vibration into the surrounding area.

Consider your TV: If it is connected securely to the wall, it turns the whole doggone wall into a speaker! To mitigate this, you'll need a wall-hanger that has built-in sound dampers.

As for your drain pipe - if it is strapped directly to the joists, you'll need some sort of hanger that insulates the pipe from the houses' structural members. If the pipe is hanging mostly free, wrapping it with something like fiberglass insulation should help quite a bit.

[Jeff Thies]

This gets my vote. Density and decoupling are how you stop transmission. Alternatively/additionally, more layers of drywall.

Jeff

[hrhofmann]

I second Jeff's second.

[hallerb]

Or replace the offending section of PVC sewer line with hubless cast iron..

PVC transmits water rushing thru it very well:(

[Joe]

After decoupling the stack from the structure as mentioned above, isolate the sound with a polyurethane closed cell foam. PU's are 'dead' materials as far as sound is concerned and clever audiophiles have used it for years. An example is the anechoic chambers used in industrial R & D labs.

Joe

[Robert Green]

Not if you use an old Hoover or Electrolux to mount it to the wall. Everyone knows that sound can't travel thru a vacuum.

Bada-bing!

-- Bobby G.

[Heathcliff]

Me three. People will tell you that you can baffle the sound with fiberglass or foam rubber or whatever, but these are not good at stopping sound transmission. What you want is mass. Put the roofing felt on an inch thick. Or consider bricking around it.-- H

[Higgs Boson]

How about straw bales? Straight question. Straw bales are used in some innovative housing, being cheap and good insulation, I have heard.

HB

[jamesgangnc]

Try to eliminate any contact between the pipe and the house frame. That may mean enlarging holes. You can still use hangers bot do not use anymore than you have to. You can buy sound insulation, it is often used in bathroom interior walls. Do not allow any of the new column frame to contact the pipe. Separation is the best way to reduce sound.

[ransley]

I bet its Pvc, the best idea is put in cast iron, you get almost no noise. Encase it in layers of drywall, 1.5" or more thick with each sheet seperated by a glob of caulk that you let dry hard, is often done, dont let the drywall touch the pipe.

[hallerb]

Hubless cast iron for the offending area. Just cut out the PVC and use what are really ferncos for the cast iron connections.

then add some sound insulation just to be on the safe side