Finally tackling sound proofing my live in basement

I have a very comfortable and small <300 sq ft live in basement that we have finally decided must be sound proofed from the main house above. On two adjoining sides the walls are drywall over brick foundation (underground) and on the other two sides, the walls are simply 1/2" drywall separating the room from a laundry/utility room. I will address these walls after the ceiling.

The prime culprit is the ceiling between the basement suite and the house above. You can hear conversations between the two rooms and footfall traffic sounds like exactly that from the basement suite. The suite ceiling is 3/8" drywall installed on 2X2's strung across the joists. There is no insulation between the ceiling and flooring above and the drywall is interrupted with about 6 recessed can lights. Yes, I now realize that the previous owner created this suite 'on the cheap'. Moving on.

The single largest noise issue is foot falls followed by conversational noise passing from the house above to the suite below. My plan is to entirely remove the current suite ceiling and 2X2 frame, insulate the gap with R-13 or R19 cheap pink stuff. Re-hang a decoupled ceiling using WAVE hangers WAVE Hanger | Noise Control Ceiling Hanger for Wood-Framed Construction The ceiling will consist of 2 layers of 5/8" drywall offset. If I can talk my wife into it, I will eliminate the recessed lighting in favor of leaving the drywall as one smooth decoupled surface.

My question is this. While I have the ceiling torn down, am I overlooking something that I can address while I have access. For example. Should I cut 16" wide strips of 5/8" drywall and apply them to the underside of the subfloor, perhaps with Green Glue? Should I apply Green Glue between the two layers of drywall I will be using in the decoupled ceiling? I am aware that my largest percentage of noise reduction will occur through decoupling, is it worthwhile to introduce the dampening properties of the GG between the ceiling layers? Am I missing an opportunity here? As the house is older (100) I have read that I may be able to eliminate certain types of creaking by also stiffening the joist structure while it is exposed with 2X4 running across them in a lattice?

Part two of the project will be applying another layer of 5/8" drywall to the two wall separating the suite from the laundry room.

Any advice will be much appreciated. TIA.

Paul

 

Welcome to the forums!

Mineral wool is more effective at dampening sound than fiberglass.

That ceiling sounds labor intensive, heavy and blocking. I would install a suspended ceiling in a grid for access to plumbing and wiring. Patterned metal tiles would look nice in a house the age of yours. Using flexible hangers will isolate either ceiling from transmitted vibration. Light fixtures can be mounted in the grid or to electrical boxes mounted in the grid.

Some good rugs, with padding, on the floor above will help a lot.

 

NASHKAT, thank you for your response and the information you provided. In the research I have done, I thought that I had learned that it is counter intuitive, however, mineral wool is actually less effective than fiberglass in providing sound mitigation. I will re read those studies to make sure that I am interpreting the data correctly. I will check out these suspended metal tiles you recommend. Unfortunately area rugs upstairs are not an option though I agree that this would be the least expensive and fastest remedy. Thank you for your advice and time.

 

Keep us posted and ask about anything else that comes up.

 

Roxul STC 52; http://www.roxul.com/files/RX-NA_EN/pdf/SafenSound.pdf

Fiberglass STC 50, #10- 5/8"GWB each side; http://www.certainteed.com/resources...%20Control.pdf 1/2" GWB is STC 46.

IMHO, a suspended ceiling would leave many open cracks (harder to get air-tight) for sound compared to drywall; taped/mudded (air-tight).

Compare different thickness changes of insulation only in same stud configuration; pp.15 and pp.17; https://docs.google.com/viewer?a=v&q...5-Nlw11eErzv_A

Density is a biggie; https://docs.google.com/viewer?a=v&q...3EnQaBEE-SpO8g

Floors; http://www.bobgolds.com/AbsorptionCoefficients.htm

If a techie; Research Highlight 2000-109 Summary Report For Consortium On Fire Resistance And Sound Insulation Of Floors: Sound Transmission Class And Impact Insulation Class Results (CMHC Canada Mortgage and Housing Corporation)

Resilient channels = 4-7 STC improvement, neoprene isolators = 8-11, pp.3; http://www.google.com/url?sa=t&rct=j...AMLzJw&cad=rja

Last, but not least, lol; Georgia-Pacific HushBoard Sound Deadening Board


Gary

 

No taping or mudding needed. In fact, trying to do something like that would reduce the sound-deadening properties of a suspended ceiling.

While I'm partial to the look of a stamped-metal ceiling in an older house, nothing, but nothing, kills sound as effectively as an SOP acoustical tile suspended ceiling, IMX.

 

I should have used a coma after "drywall" so as not to have readers think anyone would suggest tape/mud on a suspended ceiling-- kind of defeats the access purpose, don't you think... very difficult (if not impossible as the panels set on the grids. lol. I bow to Ted White on the "hush board" though, an expert on soundproofing more so than a contractor, myself or electrician; http://www.doityourself.com/forum/ba...ggestions.html

Gary

 

From a practical perspective, I would use fiberglass batts. If I had all the free insulation I could use, I'd use the cheapest fiberglass batts available.

STC doesn't measure low frequencies so as a metric is is at best incomplete, and at worst meaningless. Since high frequencies are very easy to deal with we really should concern ourselves with what insulation does better in the low frequencies. The answer is lowly fiberglass.

Sound boards of all types have limited value in any construction. It is too stiff to decouple, too dense for absorption, insufficient mass to look at as a mass contributor. It does nothing particularly well.

Resilient channel is the #1 product involved in soundproofing lawsuits. I would avoid it.

To soundproof, you are looking at sealed mass. Not a dropped ceiling. You're looking at double 5/8" drywall at a minimum. Given that nice mass as a starting point, you may as well get the least expensive clip not the most expensive as the OP originally referenced. As mass increases, the differences in performance between the clips decreases. You absolutely want the mass and would never, ever substitute an exotic clip for less mass.

You might find this aticle useful: How to Soundproof a Ceiling - Soundproofing Products for Ceilings