Soundproofing floor above garage

[sheslostcontrol]

I have a detached garage with an upper level for office & soon-to-be music studio. My question has to do with sound proofing the floor. The upper area has 8' ceilings, so adding a sub floor is not an option.

The area below is a shop with 10' ceilings, engineered OSB I-beams, and a standard garage door entrance (sound pours through the door). Concern is that the shop area will act like a huge bass drum to the outside world.

I'm already going to use carpet and a good pad for starters, but is there anything else I might want to put down on the floor, or in the shop joists? Everything is exposed right now so now is the time. I'm concerned that adding R-30 in the joists won't do much for stopping sound waves.

Thanks for any & all suggestions/advice.

 

[pcmeiners]

Unless your using acoustic fiberglass it will not help much. Had a similar situation, I pumped cellulose fiber (packed) in the joists. There is a Homasote product, but I have never used it.

http://www.homasote.com/products/440-Soundbarrier.aspx

 

[slickgt1]

Roxul Insulation, has a product called comfort bat. Reduces sound a lot. It is only R15 though. I have tenants above my garage, so what I did is put in the R15 comfort bat, then Roxul R23 under it. Gotta tell you, every peice that I put in, the tenants conversations were heard from the areas where the wasn't any insulation. Now I don't hear them at all. Hope they don't hear me either. Research it some.

I also like it for the fact that it is not fiberglass, you can cut and trim it with a giant bread knife, you don't need to staple it, and more. Search around for it. I don't want to sound like their salesperson. lol.

 

[iggi11]

I built a home theatre in my basement a few years ago and researched this topic quite a bit. If you look into how home theatres are constructed you will find that the entire room is sorta suspended. Insulation will help and you need to insulate as if you live in the north pole as sound travels through cracks worse than air. In addition you will want to look at a floor treatment that starts with a modular sub-floor that they use in basements to keep things warm and dry. They have a backer on them like Dricore or Barricade. This keeps the air sealed, absorbs the sound, and dampens the reverbs into the framing members (which is by far the biggest problem). After the studs you want to hang the sheet rock or other walls on a suspended j groove (not sure of the technical term here). These fasten to the studs then you hang your walls on them. This helps to suspend the walls and again reduce the transfer of the sound into the studs as the J groove absorbs it. Lastly you want to make sure to seal up any crack and i mean every single crack there is around seams, lights, electrics everything. Lastly make sure to use the foam studio dampeners.

When i did this i was able to reduce noise levels from 80db to less than 30db. Hope this helps.

 

[rsanter]

blow foam in there

bob

 

[jam0o0]

even stuff not designed for sound insulation works some what. we used rectangular flower pots filled with dirt and stacked into a doghouse shape to cut down on the sound from a generator. it easily cut the sound by 60%ish.

look for the best stuff but don't rule out regular insulation just cause it doesn't say sound proof on it. fiberglass batts do absorb sound. just not as well as some of the engineered solutions.

 

[sheslostcontrol]

Getting some more ideas on insulation. thanks.

@iggi11 -- can't do raised floors, the ceilings are only 8' tall. Not willing to live with reduced ceiling height. Have enough of that in my basement!

 

[stanleyoutdoors]

I am a noise and vibration engineer.

When trying to block noise, mass is your best friend. Put as much mass (weight) between you and the noise. For walls, the cheapest/easiest thing to to do is just slap another layer of drywall over the old. For floor, I'd recommend something like cement board. Again, heavier is better. And if you can isolate it, that's good too. Like some kind of rubber between the joists and floor. Most importantly, seal any noise "leaks" like cracks under doors, windows, etc. Try to figure out what paths the noise can take (up the hall, under the door, etc) and seal them off.
Good luck

 

[sheslostcontrol]

What about pouring an inch of concrete over the existing osb? Theoretically, wouldn't that be best?

 

[theoldwizard1]

Any insulation will help, but fiberglass insulation is not your best choice. There are specific types designed to lower noise.

As mentioned do NOT attach any ceiling material directly to the joists !

 

[sheslostcontrol]

Where do I find resilient channel locally? I've walked through home depot a few times but didn't see it. Also where is the best (cheapest) place to buy clips?

 

[Painter123]

RC channel can be found at any Drywall supply house
They might stock 10ft lengths but 20ft is the most commen

having been a drywaller for years and seen/done a bunch of sound rooms I would

either use spray foam or roxwoll with fiberglass to fill the cavitys
then glue an screw 1 layer of 5/8 and firetape or caulk all the joints
hang a second layer of 5/8 stagering all the joints/seams then firetape
then put up the RC channel and 5/8 rock finished to your choice

for the floor either 1" of concrete or even a second layer of your subfloor glued an screwed to the first
then pad an carpet

 

[sheslostcontrol]

The floor joists are engineered OSB I-beams. At what point do I concern myself with having too much weight on them? IE -- 1" of concrete...

 

[tncatadjuster]

What about pouring an inch of concrete over the existing osb? Theoretically, wouldn't that be best?

Concrete is not the material for this application. Look in the phone book for self-leveling underlayment contractors. Gypsum Floors comes to mind as the product, and is fire rated as well. You could put in floor heat at the same time.

Bang away.

 

[willymakeit]

Google STC ratings for sound. United Gypsum ect. will give the stc ratings on varios wall and ceiling assemblies and how they are constructed. Hope this helps.

 

[Painter123]

The floor joists are engineered OSB I-beams. At what point do I concern myself with having too much weight on them? IE -- 1" of concrete...

Yea it's usually called Gypcrete or Lightweight
They use to use it in a lot of the appartments we use to do but they would pour it 3" thick