Sound Proofing vs. Absorbing Garage Ceiling

[Handyandy23]

I moved into a new build house where the garage is under a bedroom, and I'm looking to try and reduce the amount of sound that is transmitted to the bedroom. The problem is I'm not really sure if what I want is just sound proofing, or if sound absorbing / acoustic materials would help too. I've been doing a lot of reading online, but not really getting a clear answer in my head. Most sources say sound absorbing only helps to reduce echos and resonance inside the room, but then when I search for sound proofing tiles online the first results are foam acoustic tiles.

To my knowledge the ceiling has spray insulation in the joists, and then the ceiling is dropped several inches from the bottom of the joists using 2x4 drops, with a separate 2x4 frame built on those drops, and then drywalled on top. I believe it was done this way to clear some duct work and a metal support beam in the ceiling, but based on my research this should also help with a 'dead space' in between to cut down on sound transmission.

Are there any tiles or panels that I could glue or attach to the drywall that would help with noise in the bedroom above? Ideally I would add some of the Roxul safe & sound, but I don't really want to cut down the new drywall, so I'd much prefer something I could add on top. I've also read that adding another sheet of drywall would help, but again the ideal solution for me would be something that wouldn't require further 'finishing' - a tile or panel I could glue on the drywall, maybe paint, and be done with it, rather than having to tape and mud more seams.

Does a product like this exist? If I stuck those foam acoustic tiles to the ceiling would that help at all? Or are the solutions I already mentioned (more drywall, insulation) the only viable options? Thanks in advance.

 

[kd7gab]

I moved into a new build house where the garage is under a bedroom, and I'm looking to try and reduce the amount of sound that is transmitted to the bedroom. The problem is I'm not really sure if what I want is just sound proofing, or if sound absorbing / acoustic materials would help too. I've been doing a lot of reading online, but not really getting a clear answer in my head. Most sources say sound absorbing only helps to reduce echos and resonance inside the room, but then when I search for sound proofing tiles online the first results are foam acoustic tiles.

To my knowledge the ceiling has spray insulation in the joists, and then the ceiling is dropped several inches from the bottom of the joists using 2x4 drops, with a separate 2x4 frame built on those drops, and then drywalled on top. I believe it was done this way to clear some duct work and a metal support beam in the ceiling, but based on my research this should also help with a 'dead space' in between to cut down on sound transmission.

Are there any tiles or panels that I could glue or attach to the drywall that would help with noise in the bedroom above? Ideally I would add some of the Roxul safe & sound, but I don't really want to cut down the new drywall, so I'd much prefer something I could add on top. I've also read that adding another sheet of drywall would help, but again the ideal solution for me would be something that wouldn't require further 'finishing' - a tile or panel I could glue on the drywall, maybe paint, and be done with it, rather than having to tape and mud more seams.

Does a product like this exist? If I stuck those foam acoustic tiles to the ceiling would that help at all? Or are the solutions I already mentioned (more drywall, insulation) the only viable options? Thanks in advance.

You do have a few options, not all of which will require ripping down the drywall. If you do have space between your ceiling and the bedroom floor, your could blow in dense pack cellulose. Cellulose is dirt cheap, will increase the R-value of the floor and cuts down on noise transmission. After adding the cellulose, I would use a product designed to be applied between 2 layers of drywall and add a 2nd layer, of a different thickness drywall. Something like this: http://cascadeaudio.com/commercial_residential/green_glue_soundproofing.htm

I would also recommend putting back boxes in around any ceiling electrical boxes or eliminating them and switching to surface mount runs in conduit.

Ultimately, you want to reduce the amount of harder materials and dead space. This ensures the noise from the garage would be converted to heat, instead of passing through to the bedroom.

Most damping products will not help with what you are trying to acheive. They do exactly what you said, they reduce echos and standing waves.

~Jon

Sent from my SM-N920T using Tapatalk

 

[Lelandwelds]

http://cascadeaudio.com/commercial_residential/green_glue_soundproofing.htm



Most damping products will not help with what you are trying to acheive. They do exactly what you said, they reduce echos and standing waves.

k

Good post.

Add mass ( sheetrock is inexpensive and heavy)
Add something that doesnt vibrate well ( rockwool, cellulose, spray foam, homasote. They work at different frequencies. Try to be psychic? )
Add something that dampens vibration. ( green glue is easiest)
Patch penetrations (wrap electrical with clay fire sheets and seal to drywall. Messy PITA acoustic caulk for seams)
Limit sound at source (or limit worst time)
Add cover sound ( tv, music, sound machine)

Sound transmission may take a less obvious path. If not perfect on first attempt, next home will be better (or better choice. Take a radio and a friend with heavy boots). It is hard to guess which method is most effective.

 

[NUTTSGT]

A good thick padding and carpet in the bedroom will also help vs hardwood flooring.

 

[Lelandwelds]

A good thick padding and carpet in the bedroom will also help vs hardwood flooring.

+1

I helped install a Homasote product on a second floor of a church building. Went from stampede to silence.

Footfalls, noise transmission, and echo absorption are not identical.

 

[ambenz]

Quote:"I'm looking to try and reduce the amount of sound that is transmitted to the bedroom."
What exactly is the nature of the sound? Big garage door opening? Occupants grinding metal? Jamming a stereo while working on the cars? Swearing? All of the above?
The reason I ask is the Big garage door is usually the issue of being loud while opening and closing. There are specific door and opener products you can buy to eliminate noise issues with the door. See various threads on the subject using the forum search function....like this one I found....https://www.garagejournal.com/forum/showthread.php?t=351913&highlight=nylon+garage+door+wheels

Investigating the ceiling cavities and filling any voids with insulation, using standoffs to mount spaced acoustic tiles to deaden sound and stop the bounce of compression waves, and realizing you are under the bedroom...and it is 3am. ...you will never be happy with that bedroom over the garage, just manage it the best you can!

 

[Handyandy23]

Thanks for the info everyone.

My main worry is I'm having a gas heater installed close to the ceiling. It's a 45000 BTU Modine 'Hot Dawg' that they rate at 57 db at 5 ft, and I'm having a hard time imagining how loud that will be or how much of that will transmit through to the bedroom. Really it's just the blower that will make noise.

If that is the case would adding an extra layer of drywall or some soundproofing material directly over the heater be good enough to alleviate some noise transfer from the unit? Or will the sound just 'go around' that barrier? And is there a 'preferred' way to mount a heater such as this to reduce noise transfer?

 

[Abeo]

57 dB is not that loud, and I'm not sure if you would hear it through the floor. I'd be more worried about vibration than noise. I think if it was hung using rubber isolation mounts that would be good enough.

A vacuum cleaner is a lot louder than 57 dB. Can you hear that through the floor?

 

[kd7gab]

abeo is on the right track. You will most likely get more vibration than direct noise through the floor. I highly recommend the suggested isolation mounts. They can be found pretty inexpensively online or your installer (assuming this isn't DIY installed) should be able to provide these.

Some of the quietest blowers, fans, motors produce surprisingly large amounts of vibration. I've encountered this first hand but I'm very sensitive to that kind of noise.

One of the other comments was right on, you may not need to worry about the noise/vibration unless you run the unit while someone is trying to sleep... The person sleeping in that room can also be the deciding factor on what mitigation steps you need to take.

~Jon

Sent from my SM-N920T using Tapatalk

 

[ard]

What is the connection path between inside the garage to the bedroom?

If it is as follows, you have a direct conducted sound path:

Sheetrock, nailed to 2x4, nailed to floor joist, nailed to plywood, nailed to hardwood?

IMO the open spaces around stuff is almost less important that the direct conduction paths between the spaces. Homasote on the floor will decouple. Isolation channels below with a new layer of ceiling may also help.

And NEVER hang any noise source from the wall or floor you are trying to avoid. Mount the heater on the wall or better on the floor. Weld up a rack if needed to hold it at ceiling level.

IMO

 

[Lelandwelds]

You could spend time around industrial equipment, grinders, and loud music. I am partially deaf to things that annoy most people.

"Spot" soundproofing rarely works. Resilient steel channels are easily defeated by a couple of screws set too deeply. Green glue is almost goof proof. Isolation pads are easily fabbed up. (Make UHMW or wood blocks to match heater mounting points. Separate by somewhat soft rubber , cork, etc. Screw in first block complete with bolts. Install the rest and heater.)

I don't approve but suspending item from cordage works OK.

I like the muffler hanger idea. I need to try that someday.

 

[finn]

You might want to reconsider the hanging garage heater and look at a residential downdraft furnace with a variable speed fan.

The Goodman residential furnace is much quieter than my hanging shop heaters, albeit at a higher cost. Higher end furnaces are probably quieter than the budget oriented Goodman.

 

[No Noise Dude]

As opposed to sound dampening, what you’re looking for is sound isolation. The most economical way to isolate noise from the garage from transmitting into the space above is to insulate with fiberglass batt and utilize two each layers of 5/8-inch Sheetrock. Tape and mud the first layer of Sheetrock and stagger the seams on the second layer of Sheetrock. Minimize any openings from the garage into the space above as this will short circuit the intended mass of the Sheetrock. When dealing with sound isolation, mass is the name of the game.

 

[CraigStu]

This is the type of hanger I would use
https://www.autopartswarehouse.com/...nts/exhaust-hanger/eastern-exhaust/eastee8180
Good thing is you can make the steel parts easily by bending some 3/8 round steel w/ a vise and a hammer. You want it to look like the right side of this
https://www.autopartswarehouse.com/...-and-components/exhaust-hanger/walker/wk35199
These style hangers are used by pretty much every car manufacturer so you can usually get them readily from any auto parts store.