Author Topic: Soundproofing a shared wall in a duplex  (Read 8828 times)

CS

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Soundproofing a shared wall in a duplex
« on: April 27, 2011, 10:00:46 PM »
I own 1/2 of a duplex built in 1890.  There is a shared wall running the length of unit, and the noise transmission is terrible.  You can hear conversations, snoring, walking, etc.  The wall is not original as it is drywall.  I believe it's a simple 2x4 frame wall with no insulation (based on noise transmission).  Additionally, the ceiling was originally 20" higher and has been lowered, and I do not know what the separating wall looks like above the ceiling level, but I suspect that this is an additional source of transmission.  Floors on both sides are hardwood.  I'm looking for the best option to maximize sound transmission reduction.

Thanks,
CS

Randy S

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Re: Soundproofing a shared wall in a duplex
« Reply #1 on: April 29, 2011, 04:22:14 PM »
Remove existing drywall, fill cavity with cotton fiber insulation. Staple #1 MLV directly to the studs, seal and tape.
Attach Clips to studs through mlv and install channel, attach 5/8" sheet rock to channel only! not making hard connections to perimeter. this gap filled with acoustical caulk.
Assess results, if more reduction is desired add second layer of 5/8" sheet rock with a 3 tube per 4' x 8' sheet with Green glue compound.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
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Fax.760-752-3040

CS

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Re: Soundproofing a shared wall in a duplex
« Reply #2 on: May 02, 2011, 01:09:21 AM »
Thanks Randy.  Is it worth the cost to use a specialized type of sheet rock, such as Quietrock or a similar product? 

CS

Randy S

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Re: Soundproofing a shared wall in a duplex
« Reply #3 on: May 02, 2011, 04:20:18 PM »
Not in our opinion, if your using Green glue than double 5/8" sheet rock is fine.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

CS

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Re: Soundproofing a shared wall in a duplex
« Reply #4 on: May 03, 2011, 09:40:35 PM »
Gotcha.  One last question: I was able to cut out a hole in the closet wall and look above the ceiling in the room I'd like to soundproof.  The current drywall on the shared wall runs to the original ceiling height, which is 20" above the current ceiling level.  Now I'd be able to get the insulation into this portion of the shared wall by pushing it up from the bottom, but without cutting out a portion of the ceiling, there'd be no way to lay the MLV/channeling/new dry wall above the ceiling level.  So, my question is if it is worth doing this job up to the current ceiling, or would you recommend taking on the cost/labor of cutting out and replacing the ceiling (at least the part which abuts to the shared wall)?

Thanks for all the help,

CS

Randy S

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Re: Soundproofing a shared wall in a duplex
« Reply #5 on: May 03, 2011, 10:19:13 PM »
If you do a portion of the wall and not the entire wall than its like having the window cracked in your car..all the sound will focus above the wall where it meats the ceiling then the sound will come down...when your doing a floated wall you can not have a hard connection around the perimeter. So I would advise you to do the entire wall if your going to do the project..its worth it and you most likely will not have to address the ceiling.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

CS

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Re: Soundproofing a shared wall in a duplex
« Reply #6 on: May 07, 2011, 03:51:20 PM »
Understood.  I plan on doing the entire wall that is exposed.  The new wall would be floated out and where it meets the ceiling at the top would be filled in with an 1/8 " of acoustical caulk. 

One more question popped up as I was putting together my order:  What type of tape is best for the the seams and what sounds clips are best? 

Thanks,

CS

Randy S

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Re: Soundproofing a shared wall in a duplex
« Reply #7 on: May 09, 2011, 04:10:27 PM »
5mm lead tape for seams in field of MLV,  and our ssp-1 clips are the best for decoupling.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040