Author Topic: 2nd try at soundproofing suite ceiling. Start over or add to what I've got?  (Read 3128 times)

audi99

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Hi - I'm a homeowner with a suite in my basement. House is 1yr old, and has hardwood on the floor above the suite. The impact and airborne noise in the suite from the upstairs level of the house was terrible, so I had cellulose insulation blown into the ceiling of the suite last year.  It helped muffle the voices so you couldn't hear what was being said in the suite (or vice versa from upstairs), but you can definitely still hear there is speaking going on.  I also hear the beeps from the microwave downstairs when it finishes, etc. And the cellulose did nothing to reduce impact noise in the suite from footsteps on the hardwood floor from the level above. There are no pot lights in the ceiling of the suite, although there are some furnace ducts that travel through the suite. The ducts don't vent into the suite, the suite has its own electric baseboard heaters.

I'd like to reduce both airborne and impact noise transmission between the main floor of the house and the suite below.  My question is, should I take down the drywall in the suite, remove the cellulose, and start from scratch?  As I say, it has improved things somewhat, but not hugely, so not sure if it was a decent install in the first place. There was cellulose blown in all the joist cavities, I know because I had to repair all the holes in the drywall where the blew it in.  If recommending I keep the cellulose install, what next steps would you recommend I consider to improve the soundproofing?  I have two young sons (9&5), so there's a lot of yelling and running around from upstairs, and can be very noisy for the tenant in the suite. Am looking to improve things as much as possible, and am Ok with spending the money to do this job properly (the second time around  :)).  If I keep as is and add another layer of drywall to existing, there are some spots in the ceiling that are lower where the furnace ducts travel through the suite, so I assume I'd have to also do another layer of drywall on these too?

Thanks, Jason

Randy S

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Jason,

It is best to pull down the sheet rock and start over... you need to decouple the drywall from the joist and when the ceiling is open you have options to improve the mass and impact reduction.
Give me a call on Monday, I will be in the office and we can discuss the project and I can send you over images and instructions for you to review.

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

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

audi99

  • Guest
Hi - due to budget, I've scaled back on how far I want to go with soundproofing. I'm now considering two options. I've decided it's more important for me to reduce sounds coming from the basement suite into the upper floor of the house, rather than worry as much about sound coming from upstairs to be heard in the suite. Is that any opinion on which of the following would provide better soundproofing improvements? Bear in mind I'm going to keep my existing 1/2" drywall ceiling (attached directly to joists) with cellulose.

1) Add a layer of 5/8" drywall with green glue to the existing ceiling drywall
2) Attach resilient channel to the existing drywall, and then a layer of 5/8" drywall. My contractor proposed to use long screws to attach the channels, thrugh the existing 1/2" drywall, directl ,to the joists.  Once the channels are fastened tightly to the josts, he'd back the screws off a bit so the channels hung a bit below the existing drywall. Ie. It would be floating, not be in direct contact with the existing drywall, and the 5/8" drywall would be attached in normal fashion.

Both methods above would be sealed at the edges with acoustic sealant.

I'm thinking #2 above would provide better soundproofing for footfalls than #1? But how about ambient noises, would one provide better results than other?  I'm leaning towards going with #2, but can't find much info online about people actually doing this, which leads me to think it may be a bad idea?  But in my circumstance of not wanting to remove the existing drwyall and cellulose, wondering which scenario would be better. Thanks

Randy S

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Ok,
#1 system would be for airborne sound from below being reduced going up to next floor.

system #2 is dangerous because you are creating the triple leaf system, in this scenario it would be an improvement on the airborne reduction however, the impact noise reduction would be questionable because the first layer of drywall was not decoupled from the system.


Randy S.
 
Randy Sieg

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

audi99

  • Guest
  Ok, I have decided to take the whole ceiling down and start from scratch. One question - I have some furnace duct bulkheads. They attach to the joists with 2x4s. Do people put soundbars on the bottoms of these and then 2 layers of drywall?  Or just add another layer of drywall with green glue to the layer of drywall already on them?

Randy S

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They need to be isolated from the new ceiling, if it is framed in then yes, you will clip and channel under the framing to keep the duct work out of the sound bubble so to speak.
can you post me a photo of it?

Randy S.
Randy Sieg

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

audi99

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Hi - would I install the clip/channel to the bottom of the bulkheads?  Or would I put the clip/channels on the bottom of the joists and then attach the bulkhead framing to the channel (major rework to demo the bulkhead frames & re-install).  Re Roxul, was thinking that one I take the ceiling down, I could probably reach into the bulkheads and stuff them with Roxul.

Here are pics.  What is best way to soundproof these bulkheads?  Am thinking I'm going to need to remove the cabinets to add clips/channels and 2 layers of 5/8" drywall.



Randy S

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yes the soundproofing and clips and channel would go on the bottom of the 2x4 framing and therefore the cabinets would need to be re installed..
Yes you want to fill any and all voids with the roxul.

Randy S.
Randy Sieg

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

audi99

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What should I do with the vertical side of the bulkheads?  Should the have clips & channels installed as well?  Thanks for all your help.

Randy S

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yes the verticals would need clip and channel as well.
You are basically making sure everything in the ceiling is isolated from the new soundproof ceiling system.

Randy S.
Randy Sieg

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