Best strategy to rehang the ceiling drywall?
Our basement (ground level) room suffers tremendously from the noise in the upper level where the kitchen and dining table are. Walking and moving chairs noise is very pronounced downstairs. I’d like to improve on it. We should have used resilient channel before hanging that ceiling drywall, but we did not. There are also 16” tall floor joists – maybe the cavity even amplifies the noise? First floor is just the hardwood floor with a minimal (very thin) cork layer below it.
I presume it is best not to remove the existing drywall from the ceiling in the basement, just open it up in few spots to drop down the lights. The contractor suggest attaching a horizontal channel all around the walls, few inches below ceiling, to rest the drywall edges there, and otherwise only use wire to hang the second layer of drywall. Are there some such products/devices available or is this all a kluge? (Any pictures/description on what that should be..?). He believes resilient channel on its own (attached to ceiling) won’t be good enough. Could people recommend some products and/or suggest the best strategies? I would be probably willing to pay for SilentFX or similar drywall (or Homasote?) that also dampen the acoustical wave. Is IsoTrax from soundproofcow.com good?
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Don't do as your contractor recommends. Adding additional layers of drywall with a gap between it and the existing layer is a very common mistake and makes the sound attenuation worse not better.
It illustrates the problems with adding any acoustical dampening in isolation. They often act in unpredictable ways, sometimes working, sometimes making things worse. That's why wall and ceiling are tested and rated as complete assemblies.
I would suggest looking at tested assemblies and finding one that looks like it would work in your situation. They are online at a variety of sources. Try searching for "STC rated floor/ceiling assemblies", or some variation on that. A well installed version of a tested assembly will perform predictably and solve your problem.
Thank you for your advice! We should then proceed to remove the existing ceiling drywall first, is that correct?
It depends on what assembly you choose.
You may find it best to start from scratch and remove the drywall, add Res bar, perhaps with clips, insulate the joist bays and then drywall - with a whole lot of variations on what materials and how many layers you use.
Or you may find an assembly that just adds layers to the existing ceiling. Green glue, mass-loaded vinyl, specialty drywall...
The main thing is to identify an assembly that has a sufficient STC rating and suits your situation.