Author Topic: condo shared wall renovation (questions)  (Read 4538 times)

cyr0nk0r

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condo shared wall renovation (questions)
« on: December 07, 2015, 05:15:40 AM »
It will be a shared bedroom wall in a new condo. The principals will be the same though, the only difference is I'm not doing the ceiling or the other 3 walls.

I can't do anything with the ceiling (steel beam construction), or the floor (concrete slabs that I can't modify in any way per the HOA).
The wall now is (2) 5/8" sheetrock layers on each side of the wall, using metal studs that are 3 5/8". There is fiberglass insulation in there now, which I'm sure is pretty cheap stuff.

The new wall will consist of the following and wanted to get input from the community if I'm on the right track after quite extensive research.
I can't do anything with their side of the wall, but this what I've come up with.

(1) backside of their wall, Damplifer sheets cut into 18" wide strips in whatever height to go up the 8' wall floor to ceiling in between each 16" gap. The extra 1" on either side is to secure the sheets to the studs. (Doing B stock to save money since this step isn't the most critical)
http://store.secondskinaudio.com/dam...ock-16-sheets/
(2) Foil tape on each side of each stud to secure the Damplifer strips to. (so in the event of a re-model you can somewhat easily remove the mats without completely warping the studs.
http://store.secondskinaudio.com/foi...ll-x-150-feet/
(3) Standard fiberglass insulation. R-13. Was looking into Denim insulation or rockwool but I've heard the difference isn't astronomical and trying to save money for other parts of the sound project so going easy on the insulation.
http://www.homedepot.com/p/Owens-Cor...BF10/202676829
(4) IsoMax sound clips. Going with IsoMax since these are a good price and I don't lose as much internal space.
http://www.amazon.com/10-IsoMax-Soun...eywords=isomax
(5) Resilient hat channel.
http://www.homedepot.com/p/Super-Stu...8100/202093381
(6) Layer 1 of 5/8" sheetrock. Each layer will have a 1/8" gap between floor, ceiling, and between each sheet for later acoustical sealant.
http://www.homedepot.com/p/Sheetrock...1308/100321591
(7) Green Glue. 1.5 tubes per sheet.
http://www.amazon.com/Case-Green-Glu.../dp/B000SKWD8Y
(8) Layer 2 of 5/8" sheetrock. Sheetrock will be staggered over the 1st layer so seams don't align.
(9) GreenGlue noise sealant in between all gaps of sheetrock on both layers.
http://www.greengluecompany.com/prod...oofing-sealant
(10) Then texture and paint.

Wanted to get input on if I'm going about things the right way, or overkill. I've not had any issues with noise coming from the unit above me. They did a great job of prevent sound transmission through the floors, but the shared walls not so much. This wall I'm renovating does not have any doors or windows. Just a straight 16'x8' wall.

Randy S

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Re: condo shared wall renovation (questions)
« Reply #1 on: December 08, 2015, 04:27:36 PM »
your research has you on the right path, however I see some things that are not cost effective.

1) damplifer sheets will not be as effective as simply using construction adhesive and another layer of 5/8" sheet rock or my favorite 1/2" cement board (hardie backer)..far cheaper and more bang for the buck. 1/4" notch trowel full coverage.
2) not necessary
3) yes improve the insulation ...Denim or roxul is worth the extra buck. get it local.
4) isomax clips is right on point ...we can provide them for $5.40 ea.
5) 25 gauge 7/8" channel on point.
6) the only gaps you need are around the perimeter. you do not need to gap the field nor caulk the field.
7) you should increase to 2 tubes per sheet ..even the factory states that 2 tubes per sheet is a 70% increase of performance over a single tube.  I actually use 3 per sheet in all my projects for low bass and impact.
8) yes offset seams so they do not meet in the field. no gaping of the final layer nor caulk in the field just the perimeter. if you caulk the field on the final layer you could have expansion and contraction of the caulking.
9) I would use a better brand of caulking for this job...OSI or Grabber ..not as watery and easy to finish.

Now before you caulk the final layer you want to tape mud and sand field ready for primer. then caulk..if you hit the caulking with a sander it will ruin the finish of the caulk..you can not sand caulking.
All Soundproofing materials should only be around $600 at most and that is with good insulation.

Feel free to call me
Randy S.
760-752-3030
 
Randy Sieg

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

cyr0nk0r

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Re: condo shared wall renovation (questions)
« Reply #2 on: December 09, 2015, 03:47:12 AM »
Great feedback Randy, thank you. I have some followup for you.

1) I interpret this to mean cut 5/8" sheetrock into 16" widths and glue or use adhesive to secure to the backside of the neighbors drywall. Would greenglue be benefical in this step? or better saved for the 2 layers of 5/8" later on?
A concern I have with this is the 5/8" of space lost for insulation. Is this a problem?
2) understood when going the drywall route.
3) If I do go with upgraded insulation I was looking at something like this, thoughts?
http://www.homedepot.com/p/UltraTouch-15-5-in-x-94-in-R-13-Sound-Control-Denim-Insulation-12-Bags-10003-11315/204599343
OR this
http://www.supersoundproofingsales.com/SSP-Cotton-Fiber-Insulation-35-thick-R-13-16/productinfo/09-99913-16/
4) any discount for buying large quantity of ISOMax clips?
5) I'll speak with my contractor and make sure that he's using 25 gauge.
6) understood. leave 1/8" gap around perimeter.
7) I know 2 tubes > 1.5 tubes, but GG is a little pricey. Plus, I figured with all the other steps I'm taking (hat channel, IsoMax clips, etc) that I can get away with saving a little on GG. Thoughs?
8) Do the seems on the first layer need to be covered with foil tape or can I just drywall right over them?
9) I'll look into OSI and Grabber sealants, thank you.

About your instructions for sealing the final layer, won't it look funny after painting if the sealant isn't finished and flush with the drywall?

Randy S

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Re: condo shared wall renovation (questions)
« Reply #3 on: December 09, 2015, 06:42:38 PM »
1) yes that is correct, no do not use green glue for this step. A construction adhesive works fine.
loss of 5/8" will not effect the insulation.
2) ok
3) yes denim insulation is preferred, try to get it local if you can.
4) you would need to call me direct for that.
5) ok 25 gauge for walls...ceiling would be 22 gauge.
6) ok
7) use at least 2 tubes trust me...
8) no because if you use green glue and offset the seams of the second layer there should be no leak issues.
9) we sell the grabber brand.
http://www.supersoundproofingsales.com/SSP-Acoustical-Sound-Sealant-Caulk/productinfo/09-42745-S/

Randy S.

Randy Sieg

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

cyr0nk0r

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Re: condo shared wall renovation (questions)
« Reply #4 on: December 19, 2015, 04:50:24 AM »
Randy, I have a followup question for #1. You mention it isn't necessary to use greenglue for this step. Why is that?

Also, I have another shared wall that is now part of this project that has a few different requirements.
I will be placing a stacked stone product on the wall that is ~12lb / sqft. Currently the wall has (2) layers of 5/8" drywall that my contractor wants to just put backboard on and install the stone.
This would normally be fine, but the depth of the stone will cause my to lose too much interior space.

My brainstorming led me to say... tear both layers of 5/8 drywall out. This will give me access to the backside of the neighbors wall, as well as let me replace the insulation with something much better. I would then do 5/8 drywall cut into 16" widths and put on the backside of their wall. This directly leads to me wondering why greenglue would not be ideal for this step? Especially since there wont be drywall going back up after insulation.
The current plan is the 16" drywall sections on the backside of the neighbors wall, insulation, then backerboard for the stacked stone. This will save me 1.5" in depth that the stone will take up leaving me right where I started so I don't lose any interior space.

Randy S

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Re: condo shared wall renovation (questions)
« Reply #5 on: December 21, 2015, 04:16:23 PM »
I have found in field testing that Green glue works best on a floated double layer of drywall.
when installed in between studs or for flooring layers I have had a hard time showing cost vs. reduction in the field. therefore cheaper products work just fine..my choice product for these applications is titebond 771-step.

For the new wall since you are only finishing with cement board and stone and therefore final exposed layers are not floating I do not think you will see much of a difference.

If you plan on floating that wall we would need to redesign the clip and channel layout to support that much weight added to the wall..

Randy S.
Randy Sieg

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

cyr0nk0r

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Re: condo shared wall renovation (questions)
« Reply #6 on: December 21, 2015, 06:24:27 PM »
For the new wall since you are only finishing with cement board and stone and therefore final exposed layers are not floating I do not think you will see much of a difference.
I won't see much difference between how it is now vs stacked stone? Or I won't see much difference between greenglue on the 16" length layers of drywall vs just using adhesive?

Randy S

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Re: condo shared wall renovation (questions)
« Reply #7 on: December 21, 2015, 06:39:20 PM »
greenglue on the 16" length layers of drywall vs just using adhesive in between the studs..

Green glue is best when drywall is exposed to source on floated wall system.
Randy Sieg

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

 

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