Author Topic: don't understand why I have a sound problem  (Read 4929 times)

sndproof2014

  • Guest
don't understand why I have a sound problem
« on: August 29, 2014, 12:26:48 PM »
I just moved into a townhome.  We have independent cement block walls.  Our master bedrooms are next to each other.  I can hear coughing and muffled conversations too well for my comfort.  I don't understand why.  It should be, at the least: drywall, cement block, cement block, drywall.  That should be plenty of noise protection.  I'm not sure if there's insulation.   

I have so many projects to work on, I am reluctant to do it the right way right now (i.e., tear down the drywall, add quality insulation, MLV, green glue, drywall(s).).  I'm thinking of tacking a strip of 1x4 board at the top of the existing drywall, and maybe at the base, and simply hanging MLV --perhaps with a layer of homasote resting on or tacked at the top and bottom.  I could add some insulation into the 1 inch gap between the soundproofing material and the existing drywall.  Are there any fire or mold concerns?  I have to cut out an area of the above for an outlet.  Thanks in advance...

sndproof2014

  • Guest
Re: don't understand why I have a sound problem
« Reply #1 on: August 29, 2014, 05:13:10 PM »
Someone (Dad) recommended having insulation blown into the wall and building upon the existing wall with MLV or equivalent and then adding another layer of drywall.  How much soundproofing value  does insulation add to the system compared to the additional drywall and MLV without the insulation?  The blown in will be a pain if it isn't something I can do myself.

sndproof2014

  • Guest
Re: don't understand why I have a sound problem
« Reply #2 on: August 29, 2014, 06:41:25 PM »
Blow-in insulation might not be an option.  Probe hole shows that there is only one inch between the drywall and the cement block.  ?.  I assumed 2x4.  This is probably part of the problem. 

Randy S

  • Senior Soundproofing Technical Specialist
  • Global Moderator
  • *****
  • Posts: 819
    • Super Soundproofing Co
Re: don't understand why I have a sound problem
« Reply #3 on: September 02, 2014, 03:52:49 PM »
well that 1 inch hollow gap is part of the problem, sounds like they did a wood furring strip on the block to hang the drywall..
If your going to tackle this problem, I would do it right the first time.
Remove the drywall, check to make sure the block is sealed. if not seal the block.
attach clip and channel to the block, use R-8 insulation between the channel and hang 2 layers of 5/8" sheet rock with green glue in between.

http://www.soundproofing.org/sales/ssp.htm

http://www.supersoundproofingsales.com/Green-Glue/products/34/

Randy S.


Randy Sieg

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

johnbergstromslc

  • Guest
Re: don't understand why I have a sound problem
« Reply #4 on: September 03, 2014, 08:13:35 PM »
I fully agree with Randy.  You shouldn't waste money on iffy 'band-aids' solutions and be stuck with obsolete materials later. 

If you have that bad of a noise problem with concrete block, you've got other issues going on behind the drywall.  Tear it off, remediate and seal, insulate and hang 2 layers of drywall resiliently.

sndproof2014

  • Guest
Re: don't understand why I have a sound problem
« Reply #5 on: September 05, 2014, 06:42:22 PM »
Thank you for the responses.  I apologize for not monitoring my post. I was busy doing the work: 1/2 the right way, but 1/2 not.  I also think they used a furring strip on concrete for the drywall.    I looked into adding blow-in insulation but the 4-inch machine attachments looked too big for the 1 inch gap.  I ended up tacking a layer of DB4 from Lowes and then adding 500 quietrock on top of existing 1/2 inch drywall. I spayed foam around an outlet and removed and foamed a phone jack.  I'm mudding and sanding now.  This solution was about $350-400 for one wall, which is quite pricey.  I don't have a kill room but I think I've blocked the uncomfortable noise penetration.  I won't know until carpet and baseboard is re-installed to block the noise in the 1/2 in gap between the drywall and the floorboards.  Yesterday, I read up about unsealed concrete on another site. I'm sure that's the main culprit.   If I had read that earlier, I probably would have torn out the first layer of drywall and sealed, insulated, and then added 2 layers of regular drywall.  I'm not sure the quietrock 500 is worth the $53 a sheet.  On the bright side, I have another room that might become an issue sometime in the future.  Right now my neighbor does not use that room, so noise is not a problem.

sndproof2014

  • Guest
Re: don't understand why I have a sound problem
« Reply #6 on: March 23, 2015, 03:01:55 PM »
Well, it has been 6 months now and I'm unhappy with the results.  I think my effort helped, but I can still hear too many noises.   Let's not go there.  Will sealing the concrete and adding the insulation in just that 1 wall of that room help enough to justify the work?   I'm worried that once the sound enters the concert it amplifies such that anything you do on one just side of one room will only be minor.  Another thought is adding wall-to-wall bookshelves with insulation or board behind it.   

Randy S

  • Senior Soundproofing Technical Specialist
  • Global Moderator
  • *****
  • Posts: 819
    • Super Soundproofing Co
Re: don't understand why I have a sound problem
« Reply #7 on: March 23, 2015, 04:42:21 PM »
yes concrete is an amplifier for vibration @ 10,600 fps this is why we recommended you floating new drywall on clips and channel and get rid of the wood furring connections and yes the sound will always go to the area of least resistance so doing one wall will move the sound elsewhere but the flanking noise will be at a lessor value.
its hard to say that band-aids are cost effective as opposed to doing the job right in its entirety.
I can relate with your frustration but sound is going to do what it does and that will never change so when you do single partitions there will always be a value of flanking noise....
It is hard to say if the book shelves will add a lot to the reduction but if you go that route do not let them touch the wall no matter what.

Feel free to contact me direct

Randy S.


Randy Sieg

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

sndproof2014

  • Guest
Re: don't understand why I have a sound problem
« Reply #8 on: March 23, 2015, 04:57:51 PM »
Thank you Randy for the helpful information.  I have some things to consider. I will make sure to take advantage of your offer.   Tom

 

anything