Soudproofing My Office

[tenshi]

I am finishing a large room on the lower level to act as an office and man cave. I want to soundproof it. Nothing extreme or high end, just enough so that watching TV or playing video games with a decent surround system won't disturb someone in the next room. It's currently 1/2" drywall on 5 sides with poured concrete (soon to be tiled) on the floor. Ceiling is about 8ft high and total area is about 18' x 21' = 378 square feet. When I finish it off, I will probably be lining the walls with faux brick tiling, so leaving that option open important for whatever wall I use. Price is a concern (ideally $1k or less if possible). Best bang for the buck is what I have in mind.

I found this: http://www.audimutesoundproofing.com/sound-barrier.aspx. It's pricier than I'd like. I could cover all of the walls and ceiling then sandwich it between a new layer of 1/2" drywall to go over the original. It has an STC of 19 when sandwiched between studs and drywall or two sheets of drywall. ($1.38 per square ft)

Someone in a different thread also mentioned homasote sound barrier 440, which claims to have an STC of 53. I could lay this over the original drywall, replace the old drywall, or use it in conjunction with sound barrier vinyl sheet if that's necessary. http://www.homasote.com/assets/files/products/snapad3_2013.pdf ($0.75 per square foot)

I am willing to replace my existing drywall on the floors and ceilings, but only if you guys think it's necessary. I have looked at rock insulation to go between the studs, but what I've seen is extremely pricey.

What are your suggestions? Any other products? Anything else that I have missed?

 

[tenshi]

I came across another budget option. It would require ripping out the existing drywall, but it would save a lot of money:
http://www.instructables.com/id/Soundproof-Your-Garage-Walls-Using-My-Cleat-Meth/

I could do this with normal drywall, or perhaps use drywall and homasote sound barrier together on top of the "cheater channels".

 

[Speedskater]

The Green Glue company has a ton of info about soundproofing a room.
http://www.greengluecompany.com/

Yes, it's green, but it's not glue.

 

[TLS Guy]

What is your HVAC system? If it used ducts then it makes soundproofing pretty much a waste of time and money. The ducts at as a megaphone carrying the sound from room to room.

If a home has AC it pretty much has to have ducts. That means of you are going to sound proof a room in a building with HVAC ducts, then you have to go to the trouble of isolating the HVAC which pretty much means giving it its own system.

 

[tenshi]

@TLS Guy
The room was added after the house was built and still remains half-finished. The duct system does not tie into this room. I'll be adding separate heating and possibly cooling.

 

[tenshi]

I came across many posts referencing things like "GG" or "QR" or "GG+QR" and I had no idea what they were talking about. I finally found some more sources that pointed to these products:

http://www.greengluecompany.com/ (thanks @Speedskater)

https://www.quietrock.com/

Both look like much better options than the vinyl or homasote. Most discussion seems to agree that green glue sandwhiched in between 2 standard half inch drywall gypsum boards will be cheaper and perform better than adding a layer of quietrock.

I was wondering if anyone can answer any of the following questions:

1. If I went with a green glue sammich, would there be any significant effectiveness in upping the outer layer to 5/8" instead of 1/2" gypsum?
2. How would a simple green glue sandwich compare to a makeshift resilient channel method like I linked above?
3. Would I have significantly better gains if I did a resilient channel with a green glue sandwich attached to those channels, or would I quickly see diminishing returns?
4. Is there a good reason to do a quietrock + Green Glue + gypsum sandwich?
5. Two of my walls are outside walls (drywall, wooden studs, then concrete sheet with stucco) Do I need to soundproof the outside walls as well if my goal is to isolate the room from the rest of the house? Ambient noises and neighbors are not a big concern.
6. The ceiling is perhaps the most important part. How do I need to treat the ceiling differently than the walls?

So many options here: Thanks in advance for any info.

 

[tenshi]

Green Glue vs Quiet Glue Pro vs Carpet Adhesive
Frustratingly long video, but actually some good information:

You can get Roberts 3095 carpet glue for $10 per gallon and it reportedly has good performance.

I lean toward the green glue, but I might consider carpet adhesive for adjacent rooms.

 

[Speedskater]

Remember that Green Glue is not glue (I don't know anything about Quite Glue). Green Glue never cures (hardens). So carpet glue or Liquid Nails Sub-Flooring might work like GG when new, but what happens five years from now?

 

[Speedskater]

This great reference book is available in many libraries.

"The Master Handbook of Acoustics"
by F. Alton Everest

 

[tenshi]

Remember that Green Glue is not glue (I don't know anything about Quite Glue). Green Glue never cures (hardens). So carpet glue or Liquid Nails Sub-Flooring might work like GG when new, but what happens five years from now?

That's a fair point. It seems that the carpet glue is made so that it remains viscous after it sets as well. However, the test in this video is only conducted over a few months. It's entirely possible that something negative happens long term. To be fair, I've not seen any long-term claims about green glue either. Will its acoustic properties decline after say 10 or 20 years?