Author Topic: another ceiling question  (Read 3315 times)

karinsky

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another ceiling question
« on: March 25, 2006, 01:54:23 AM »
i am remodeling a 120 yr old victorian - its a duplex (upstairs/downstairs) - (and i will be moving into the poor-house any day now). i am currently working on the middle room downstairs. the walls and the ceiling are open. the downstairs is usually rented and there is a problem with noise from upstairs. the upstairs has softwood floors that were finished. i dropped the ball when i retrofitted the walls upstairs and did not pay attention to soudproofing, ignorantly assuming that this was a downstairs problem. now i have a chance to fix things somewhat but on a limited budget. it looks like the quickest option would be to go with supress or quietrock, but that is not in the budget.
what gets the best bang for the buck? would it be: hat channel + greenglue + double sheetrock for the ceiling? what about cotton insulation (because i have to insulate too...) ? how about the walls? same thing?
thank you in advance

johnbergstromslc

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Re: another ceiling question
« Reply #1 on: March 25, 2006, 02:16:57 AM »
Sounds like you're on the right track.  The downstairs renters will still be able to hear some of your footfall noise, but I guess that's their problem.  You can isolate a lot of airborne sound by doing exactly what you have planned.  Just remember to seal up the edges, gaps and penetrations really well.    
As for insulation, I don't know the pros and cons of cotton vs. fiberglass (in terms of absorbtion of sound) but cotton is definitely less itchy (and 3 times the price.)

karinsky

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Re: another ceiling question http://www.soundproof
« Reply #2 on: March 27, 2006, 06:13:38 PM »
thank you for the reply. how does shear wall factor into this equation?
and how about the walls? should i do hat channels in the walls as well? then insulate? then shear wall? and then also two layers of dry wall? (i'm loosing square footage here...)
here's the link to the cotton insulation. (www.soundproofing.org/infopages/natural_fiber.htm) if anyone has used this and is certain that it is measurably better than regular insulation in terms of sound control (and thus worth the price) please let me know! (i don't mind the itching)
thank you again!

johnbergstromslc

  • Guest
Re: another ceiling question
« Reply #3 on: March 28, 2006, 03:56:38 AM »
Obviously, you want to insulate first, while the walls are still open.  

If you're using Green Glue you can put a layer of it on the shear wall sheathing, then put up 2 layers of drywall with a Green Glue layer in between them too.  

Maybe putting channels on the walls is not a good idea.  As you said, you are losing floor area and we are talking about a rental here.  If the tenant decides to hang a large bookshelf or other heavy thing, he/she will either screw into a stud, short-circuiting the soundwall and all your work or perhaps hang so much weight on the wall that the drywall and channel comes off the wall and crashes down on their head.  You can get good isolation with 2 layers of 5/8" drywall and Green Glue.  Just remember to hang the ceiling resiliently - that's where most of the noise will be coming from.  Use SSP clips (sold on this site) plus hat channels.  They are the best system I've worked with.  

As for insulation, I'd stick with fiberglass.  To me, the cotton insulation seems like an unnecessary 'green' product, not really worth the premium price.  I doesn't offer any better thermal insulation (if you want primo thermal performance you should go with expanded foam but it won't give good sound absorbtion - it's too rigid.) and I seriously doubt cotton is one iota better that fiberglass in terms of absorbtion.  

I know how it goes remodeling an older house.  Save your money for other stuff...

 

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