Author Topic: decoupling vs pumping cellulose into ceiling  (Read 8114 times)

ymi

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decoupling vs pumping cellulose into ceiling
« on: June 06, 2015, 09:11:03 PM »
Hello
I have a 2 story duplex and the bottom unit can hear everything from everyday conversation and normal walking.  I am debating on either:

1. tearing down existing ceiling, adding insulation, isolation clips, resilient channels, and then a hanging ceiling

vs

2. drilling a hole, pumping cellulose into the ceiling, and then adding another layer of 5/8 inch new dry wall using green glue.

I would prefer to go with the 2nd option since I would not have to tear down the existing ceiling, but am concerned that this will not provide enough sound insulation.  Any thoughts and advice?

Thank you.

Randy S

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Re: decoupling vs pumping cellulose into ceiling
« Reply #1 on: June 08, 2015, 03:13:37 PM »
First option will give you both impact/footfall and airborne noise reduction the second option will do less airborne and very little to no impact/ footfall reduction.

Randy S.
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ymi

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Re: decoupling vs pumping cellulose into ceiling
« Reply #2 on: June 10, 2015, 10:27:52 AM »
Thank you Randy!  What if we kept the original drywall,  placed isolation clips and channels through the drywall onto the joists, and then added another 2 layers of drywall with green glue?  Will the lack of insulation make a big difference on sound insulation?  I thought I had read somewhere that insulation fibers are more for thermal insulation than sound insulation. 
Thank you again!

Randy S

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Re: decoupling vs pumping cellulose into ceiling
« Reply #3 on: June 10, 2015, 03:25:32 PM »
You will create the triple leaf effect and since neither the cavity nor the space between the 2 layers of drywall are insulated the out come will be undetermined until finished.
I would strongly advise against this type of approach, I have seen increases of impact issues when no insulation is in the air spaces... insulation is not just for thermal it will stop standing waves in the cavities instead of allowing sound to continue to bounce around.

Randy S.
Randy Sieg

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ymi

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Re: decoupling vs pumping cellulose into ceiling
« Reply #4 on: June 11, 2015, 12:24:48 AM »
Great!  Thank you so much for your help and information.  I would like to start buying some materials for the sound insulation project.  I was looking at your product website and saw a lot of different types of clips and channels. Which products do you recommend for my project? 

Thank you!

Randy S

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Re: decoupling vs pumping cellulose into ceiling
« Reply #5 on: June 11, 2015, 03:21:51 PM »
Give me a call direct and we can go over options and what materials do in certain applications this way you are able to make the same decisions we make when addressing sound issues.

Randy S.
760-752-3030 ext 3095 
Randy Sieg

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888-942-7723
Ph. 760-752-3030
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The_Mentiad

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Re: decoupling vs pumping cellulose into ceiling
« Reply #6 on: August 07, 2015, 02:37:15 PM »
I am having a similar issue (so I hope you don't mind me coat-tailing this thread).

It is basically footfall that we are dealing with from the apartment upstairs. There is also flanking noise associated with this coming from the walls.

I guess I am right in assuming that short of taking the ceiling off, insulating and decoupling and rehanging double drywall there is little that can be done yeah? No way to mitigate by opening an access and stuffing in insulation or something?

I was reading also, a website that showed a person reinforcing the bottom of the floor above with a double layer of drywall glued against the floorboards from the bottom between the rafters. Any thoughts on this?

Also, any ideas specifically in respect to dealing with the flanking noise?

Randy S

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Re: decoupling vs pumping cellulose into ceiling
« Reply #7 on: August 07, 2015, 03:22:43 PM »
you are on the right track, you must decouple in order to achieve a reduction from impact and footfall noise.
We do use drywall and or cement board in between joist beams against the subfloor to increase mass and minimize the drum head effect from subfloors.
You also want to check if you have a deflection issue at the same time and put in cross bracing if needed to stiffen the floor in the center.
Flanking noise must be dealt with the same way if you have a serious flank issue. There have been a few occasions where the flank was not that bad and a second layer of sheet rock and green glue was able to address that, but if it is bad flanking then the same decoupled system will need to be installed.
Feel free to contact me direct if you would like to discuss particulars to this type of project.

Best Regards,

Randy S.
760-752-3030 ext 3095 
Randy Sieg

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

The_Mentiad

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Re: decoupling vs pumping cellulose into ceiling
« Reply #8 on: August 07, 2015, 03:36:57 PM »
Many thanks Randy. I appreciate your advice... I will let the forum know how I get on.

The_Mentiad

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Re: decoupling vs pumping cellulose into ceiling
« Reply #9 on: August 07, 2015, 05:07:25 PM »
One further thought that springs to mind: The above floor is old, and I think it is just a single layer of floor boards mounted on the joists, to what extent would overlaying parket and a sponge under-lay be a solution as compared to fixing it from below?

Randy S

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Re: decoupling vs pumping cellulose into ceiling
« Reply #10 on: August 07, 2015, 06:04:28 PM »
If the ceiling cavity is insulated and you use an underlayment with carpet and padding that would do the trick also.
But only if you have all 3 in play...cavity insulated, underlayment and carpet padding.

http://www.supersoundproofingsales.com/Mass-Loaded-Vinyl-48W-w_Closed-Cell-30-Roll/productinfo/09-00005CC-54R/

Randy S.
Randy Sieg

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888-942-7723
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The_Mentiad

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Re: decoupling vs pumping cellulose into ceiling
« Reply #11 on: August 07, 2015, 06:31:54 PM »
The situation is that we just bought the apartment but the previous owner says they are unaware of any noise issue. I am wondering if the upstairs neighbour has torn up the old parket and has sanded back the base floor boards- and that is causing the issue.

Does that sound plausible?

And if so do you think just replacing the underlay and parket could do substantially fix the issue?

Randy S

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Re: decoupling vs pumping cellulose into ceiling
« Reply #12 on: August 07, 2015, 06:37:35 PM »
that does sound plausible, however putting a parket down will not help absorb the impact noise before the subfloor and the underlayment will not function to full potential.
You would have to do carpet and padding.


Randy S.
Randy Sieg

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

The_Mentiad

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Re: decoupling vs pumping cellulose into ceiling
« Reply #13 on: August 07, 2015, 06:43:20 PM »
I'm never going to get the upstairs neighbour to put down carpet unfortunately...
I am struggling to get them to stop putting cigarettes out on my balcony :(
New parket with an underlay might possibly convince her... but if that isn't going to cut it in terms of impact noise I guess I'm going to have to work from below...

Randy S

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Re: decoupling vs pumping cellulose into ceiling
« Reply #14 on: August 07, 2015, 06:56:51 PM »
you only have 2 choices here:

1) absorb the impact before the subfloor.
or
2) unplug the sheet rock from below. decoupled ceiling system.


Randy S.
Randy Sieg

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