A new condo with with 17" floor trusses between the first unit and the unit above. Can anyone tell me if 17" of loose fill fiber glass insulation will provide similar sound proof qualities as the same amount of fiber glass batts?
Is there a code that states how much insulation is required (zone 5 - Michigan) above the garage when the garage is located below a heated living area?
Thank you,
Kevin
If you have 17" deep floor trusses full of insulation here also, the R50 should be more than enough to meet any code.
For effective sound-proofing, insulation on it’s own isn’t enough. The ceiling joists between units should be strapped with resilient channel.
And any holes that sound can travel through should be caulked/foamed (airsealed) since sound will follow the air if there are any direct airflow lines. Have to be careful to identify and stop “flanking sound” also.
Thank you for the feedback!
Kevin Goff
I believe that STC ratings that you are interested in might be found here.
bJones is on the right track.
http://www.stcratings.com/header.jpg
[size=3]STC RATINGS FOR VARIOUS WALL ASSEMBLIES
Below are the STC ratings of various wall assemblies, each presented to help illustrate concepts, improvements and rules of thumb. The estimated ratings are based on laboratory test results from various compendiums of STC ratings. It is recommended to consult a professional acoustician for more detailed information or to analyze the specifics of your project/assembly.
To view different wall assemblies, click on each point below that may apply to your project.
1. Insulation will noticeably improve the STC rating of an assembly.
Description
Estimated STC Rating
Wall Assembly
3 5/8" metal studs, 5/8" gyp (2 layers total), No insulation
38 - 40
3 5/8" metal studs, 5/8" gyp (2 layers total), Batt insulation
43 - 44
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2. Staggered or double stud walls are higher rated than single stud walls.
Description
Estimated STC Rating
Wall Assembly
2x4 stud, 5/8" gyp (2 layers total),
Batt insulation
34 - 39
Staggered studs, 5/8" gyp (2 layers total),
Batt insulation
46 - 47
2x4 studs, 5/8" gyp (2 layers total),
Batt insulation
56 - 59
3. Metal stud walls perform better than wood stud walls.
(NOTE: This only applies to single stud assemblies. For double stud assemblies, there is virtually no difference.)
Description
Estimated STC Rating
Wall Assembly
2x4 stud, 5/8" gyp (2 layers total), Batt insulation
34 - 39
3 5/8" metal studs, 5/8" gyp (2 layers total), Batt insulation
43 - 44
4. Resilient channel can improve the STC rating of an assembly.
(NOTE: These ratings are based on laboratory tests. Because of the special care required when installing resilient channels, actual results could be substantially lower.)
Description
Estimated STC Rating
Wall Assembly
2x4 stud, 5/8" gyp (2 layers total), Batt insulation
34 - 39
2x4 stud, 5/8" gyp (2 layers total), Resilient Channel, Batt insulation
45 - 52
5. Adding additional layers of drywall can improve the STC rating of an assembly.
Description
Estimated STC Rating
Wall Assembly
2x4 stud, 5/8" gyp (2 layers total), Batt insulation
34 - 39
3 5/8" metal studs, 5/8" gyp (3 layers total), Batt insulation
39 - 40
2x4 stud, 5/8" gyp (4 layers total), Batt insulation
43 - 45
6. Drywall between double studs can dramatically reduce the STC rating of an assembly.
Description
Estimated STC Rating
Wall Assembly
2x4 studs, 5/8" gyp (4 layers total), Batt insulation
44 - 45
2x4 studs, 5/8" gyp (2 layers total), Batt insulation
56 - 59
2x4 studs,5/8" gyp (3 layers total), Batt insulation
59 - 60
2x4 studs, 5/8" gyp (4 layers total), Batt insulation
58 - 63
Rules of Thumb
Recommended Ratings
Weaknesses - What You Should Know
The difference between STC and NRC
STC Ratings for Masonry Walls
Marcel 
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I’ve installed resilient channel on numerous occasions, going back 20 + years. In theory, with the channel, your drywall basically floats, away from the ceiling joists or wall studs. In a lot of the higher end homes, It’s used on the walls separating the bathrooms. Guess they dont want to hear what’s goin’ on in there:mrgreen:
I always thought it was for the Master bedroom walls. 
Marcel :mrgreen:
If they had Kids, they knew how to be wery wery quiet, so soundproofing wasn’t needed there:mrgreen: