Author Topic: Low impact sound proofing idea - Will it work?  (Read 3119 times)

ngn

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Low impact sound proofing idea - Will it work?
« on: March 06, 2014, 05:01:59 PM »
Hi,
I live in an apartment and share a wall (drywall) with a neighbor.  My toddler cries at night and we want to sleep train him (let him cry it out), but our neighbor gets pissed (I don't blame him) and knocks on the wall.  We want to sound proof that wall so that my toddler can cry all he wants and our neighbor won't be disturbed.  The wall is 12.5 feet wide and 8 feet tall.

The problem with going the typical route (adding MLV and drywall over the existing drywall) is that my landlord won't let us do all that construction.  I can't put a lot of holes and staples in the wall.  So, as a workaround I came up with an idea, but I don't know how well it will work and I wanted to check here first before spending the money.

My idea is to run a 2 x 3 strip of wood across the very top of the wall (nail it into the top beam there that runs along the top of the frame behind the drywall).  Then, I'll run another 2 x 3 strip of wood along the very bottom of the wall (screwed into the beams).  Then, I would run 8-foot-tall wood or MDF planks side by side along the wall, and they would screw into the bottom and top piece of the wood to keep them from tipping.  To be clear, the wood strips along the top and bottom of the wall would not be supporting the weight of the planks.  The planks would be free-standing (supported by the floor) and run from the floor to the ceiling.  I am screwing them in to the top and bottom strips of wood only to hold them in place and keep them from tipping.  In essence, I'm just running a standing row of MDF planks along the wall.  Originally, I was thinking of buying 4x8 pieces of MDF, but they are so heavy (and very dangerous if they tipped) that I don't feel comfortable working with them or putting them up in my kid’s room.  Instead I was thinking of running a bunch of 1 x 8 foot or 1.3 x 8 foot planks. 

There are a couple of notes about the design: 
--First, there will be a pocket of air between the planks and the wall behind it, since the planks lean up against the top and bottom strips of wood (essentially framing out the wall).
 --Second, I was thinking that I could put MLV or Peacekeeper running from the top strip of wood down to the bottom strip of wood, before putting up the row of planks.  If that is a good idea, does it matter that the MLV is only supported in two places and may bow away from the planks in the middle of the wall?  Does it matter that the MLV won’t be tight and flat and secure along the entire length of the planks?   Do I even need MLV or Peacekeeper?  Or will MDF do the trick on its own?
--Third, although the planks are butted up against each other side by side, there will still be some air gaps or weak parts between them where sound could get through.  Will that mess everything up?  What can I do to help that?  Will MLV be enough to cover that?
--Finally, if the gaps between the planks are a major problem, I was thinking that I could overlap the planks.  That is, I could run one row of planks separated by about 8 inches of space between them.  Then, I could run another row of planks placed over those gaps, essentially overlapping the planks on either side by 2 inches (assuming the width of my planks is 12 inches).  So I would have one row that is out further from the wall than the other row, but there won’t really be straight gaps.  However, since the planks are not one unified piece, I suppose that even with overlap, there are still week points and air leaks where they overlap. 

Any help is greatly appreciated.

Randy S

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Re: Low impact sound proofing idea - Will it work?
« Reply #1 on: March 06, 2014, 06:40:24 PM »
ok your idea has merit, I would do it step by step and assess the reductions at each application.

Go ahead a run the 2x3 top plate and bottom plate.
get R8 mineral wool or cotton fiber insulation to put in between the wood panels and the original wall..you do not want the hollow cavity.
get some acoustical caulk and seal the field seams and the perimeter, you can remove the caulking at a later date with ease. acoustical caulk is non hardening.
Then test...
if you need more reduction you can add mass loaded vinyl (not peacekeeper they are not the same) directly to the panels with staples and seal with tape.
as you continue to add mass you will achieve more noise reduction.
Since your putting the weight on the floor you should have no problems with this falling over..just make sure your using screws and not nails.
Randy Sieg

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888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

ngn

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Re: Low impact sound proofing idea - Will it work?
« Reply #2 on: March 07, 2014, 12:50:53 AM »
Thank you for the great reply!  Does it matter if the panels are lined up side by side (all butted together), or should I overlap the panels as I described above (staggered front row of panels placed over a back row of panels with an inch or so overlap at the edges of each panel)?  Do you recommend one method over the other?  Will it make a difference?  Butting the panels together as a single row is easier and less expensive, but I don't want to sacrifice sound proofing.

ngn

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Re: Low impact sound proofing idea - Will it work?
« Reply #3 on: March 07, 2014, 02:59:11 AM »
Also, is MDF the best material?  Or, do you recommend using another type of board?

Randy S

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Re: Low impact sound proofing idea - Will it work?
« Reply #4 on: March 07, 2014, 04:44:06 PM »
as far as the panels overlapping or butt joints, either way you will need to caulk the seams air tight..one is not better than the other as long as the system is sealed correctly. The next layer applied should be offset so seams do not meet seams.
MDF/ OSB/ drywall / cement board can be used ...the key to all this is sheer mass....you really want to build the heaviest system that you can support. when I do sound control walls I like to start at 8lbs per square foot and go up from there.

Randy Sieg

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

 

anything