Sound proofing a shop ceiling?

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Forum topic by RipFence posted 04-19-2018 02:59 PM 1017 views 0 times favorited 17 replies Add to Favorites Watch
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89 posts in 3304 days

04-19-2018 02:59 PM

Hello All:
We are considering a major garage renovation with a small apartment above. I’m wondering how much I can truly sound proof the shop ceiling / apt floor. I would hate to annoy the renters every time I turn on a saw or router. Would any of you happen to have experience with sound proofing a shop?
We would be building this from scratch so all options would be available for sound deadening materials.

17 replies so far

View msinc's profile


567 posts in 1115 days

#1 posted 04-19-2018 03:22 PM

Yes, I have experience. The most effective sound proofing is very similar to just a low R value insulation. You want it to stop, slow down or absorb the sound waves. Many people believe insulation with the highest R value that will fit is the way to go, but they are wrong…denser, tighter heavier insulation only serves to better transfer the sound waves.
There is an in-wall insulation that is purpose designed to deaden sound. It is not really expensive, but you wont find it at Lowe’s or Home Depot. I had to order mine and was surprised to find it not very dense and yet still effective. I was later told that low R value insulation will do the same thing and that is probably true.
All that said, it depends on how much space you have between the shop ceiling and the apartment floor. I used engineered floor joists that span 30 feet, so I have like 2 foot thick of space. If you have 2X10’s they are probably not going to sleep while you run a shaper no matter what you do.

Edit: One other thing, because things like the washing machine are sitting right on the floor above, I can hear it in the shop pretty loud. But, the stuff i am running in the shop are no where near like that to the upstairs apartment because they are not “directly on the ceiling” so to speak. What you hear downstairs is not the same as what makes it upstairs because of the air space above the shop.

View Mosquito's profile


10026 posts in 2904 days

#2 posted 04-19-2018 03:32 PM

It will definitely depend on the height of the garage ceiling, and like msinc said, the thickness of the floor joists. You’ll want to isolate the ceiling of the shop from the floor joists the best you can too. Some sound deadening insulation also has kits for isolation between drywall and joists/studs for that reason. Like msinc’s description of the washing machine transmitting to the shop well, you want to isolate physical contact too. If you had enough ceiling space, a drop ceiling with acoustical tiles below the actual insulated ceiling would be ideal, but given that it’s a garage I don’t know the amount of headroom you’ll have to work with, and whether losing that much to a drop ceiling is doable.

-- Mos - Twin Cities, MN - -

View Robert's profile


3607 posts in 2092 days

#3 posted 04-19-2018 03:42 PM

I’ve had some experience building soundproof walls for kennels in vet clinics.

The key is to build a double wall sheeted on both sides with 5/8 drywall. You can also use Wonderboard or 1/2” Hardie backer.

For a ceiling, install as usual – insulation & 5/8” sheetrock. You don’t need to tape seams.

Fir out a sub ceiling with 2×4’s, insulate (urethane foam is best) and cover with another layer of 5/8 drywall. This would be your finished ceiling. Ideally this wall would be separated from the ceiling by standoffs. Use long timber screws to hold to ceiling.

It won’t totally eliminate the noise, but will help immensely.

-- Everything is a prototype thats why its one of a kind!!

View JADobson's profile


1448 posts in 2722 days

#4 posted 04-19-2018 04:05 PM

My shop is in my basement. Its a mostly handtool shop but I do have a few power tools in it. I used R12 insulation between the joists and studs and resilient channel to hang the ceiling drywall on. It’s not sound proof but the sound is deadened substantially.

-- No craft is very far from the line beyond which is magic. -- Lord Dunsany — Instagram @grailwoodworks

View Rich's profile


5157 posts in 1201 days

#5 posted 04-19-2018 04:43 PM

When we had our house built on our ranch in the mid ‘90s we opted for a sound deadening board that they added to the walls. Sadly, I don’t recall the specifics for it, but a google search for “sound deadening board for ceiling” seems to return quite a bit of information on materials like it.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View therealSteveN's profile


4672 posts in 1186 days

#6 posted 04-19-2018 04:44 PM

Much of your sound deadening will come simply from either loose fill, or batt insulation between the floors. Most people really don’t use anything, they use it in the walls only. As suggested a tightly packed space will allow sound to travel, so loose fill is best. If you don’t have a budget there are panel type sheets you could put at one, or both sides, inside your drywall. Another area all of the sound proofers are using these days are special glues/mastics to hold your panels, and drywall down, they stop infiltration, and keep panels from vibrating.

Green Glue noise proofing compound

Quiet Glue adhesive

Quiet rock soundproofing drywall @ Lowes

Cork flooring upstairs will help quite a bit also.

-- Think safe, be safe

View CaptainKlutz's profile (online now)


2281 posts in 2106 days

#7 posted 04-19-2018 04:54 PM

I’ve have done noise reduction work:
Sound proofing is big business. There are many, many, many many, companies that specialize in nothing but sound reduction. Even BORG sells Owens Corning sound absorption panels these days.

Challenge is each application is different, as each room and source of noise generation is different, and goals for noise removal are different.

To fully sound proof a space you to have absorb noise and reduce vibrations created by noises hitting surfaces.
For new construction, options for controlling noise are much easier than dealing with existing spaces.
Example – In 2nd floor structures you can add special sound deadening underlay between floor and sub-floor to reduce vibration issues. You can also install a sound deadening foam layer between studs and drywall. This can sometimes avoid need for panels applied on top of drywall. In a sound proofed room, typically place 1/4”high density PE foam between 2×4 base plate and any floors to reduce noise coupling via walls.
Another trick used in home theater (depending heavily on local building codes) is eliminating nails or screws into studs connected to conjoined spaces. By using construction adhesive to bond foam sheeting to studs, and attaching drywall same way; you prevent noise connection. In a sound proofed room, typically the only fasteners used are finishing nails holding trim to walls while adhesive dries.

Challenge I had with sound proofing a garage shop was openings to outside world. If garage doors are open while you work, then noise escapes and will skirt around any sound proofing in garage. So will still hear noise through windows and outside walls, unless you make the apartment a completely sound proofed space, or work with doors/windows closed.

Suggest easiest way to learn noise reduction is consult with a couple of local sound proofing specialists. If you have some preliminary plans, they will gladly advise design changes and suggest materials to create sound proofed space, and give you quotes. Even if you do not spend thousands they think is required to create a sound dead apartment, You will learn a lot about how to minimize noise from shop and pick among various alternatives.

Best Luck.

-- I'm an engineer not a woodworker, but I can randomly find useful tools and furniture inside a pile of lumber!

View dhazelton's profile


2839 posts in 2908 days

#8 posted 04-19-2018 04:57 PM

Renters have a right to enjoy what they pay for without hearing table saws or compressors and you will never TOTALLY eliminate the noise.

View Rich's profile


5157 posts in 1201 days

#9 posted 04-19-2018 05:22 PM

Renters have a right to enjoy what they pay for without hearing table saws or compressors and you will never TOTALLY eliminate the noise.

- dhazelton

It’s a simple matter to include an agreement in the lease and specify what times of day the work can occur.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View Kelly's profile


2639 posts in 3556 days

#10 posted 04-19-2018 05:59 PM

There are many approaches to sound proofing, many which were already mentioned.

Some few years back, I did a major remodel of an eighty year old farm house. The remodel involved completely rebuilding several exterior walls, installing and removing windows and doors and so on.

The owners gave me a lot of room and I gave them a lot of extras. I got to play and experiment more than a little and learned many interesting things. For example, bored, one day, I grabbed a few tubes of caulking and, with the rock off and no insulation on the kitchen walls, caulked every joint I could find. I caulked 2x’s to Tyveck, studs to sill plates, around windows and doors, and so on.

A few days later, I was working and it was really quiet in the kitchen. I walked over to the French door to toss something on to the deck and discovered a significant wind storm was occurring. That was the day I learned how huge an improvement you could make by stopping air flow.

Stopping air movement probably did more than double, offset, no contact walls, double layers of rock and special boards and things.

I already knew sound was rarefaction and compressions of air waves, but, that day, I got to see, in action, what happens to sound when you impede air movement.

Of course, this is not the only solution, but, without it, all the other methods described would be worthless.

Another experiment I did was, in the course of remodeling one of the bathrooms, I stacked layers of rock onto the inside wall of the finished rock. I only went a couple layers deep, but that, combined with an exterior tread plate on the bath door, went a long ways to absorbing sound (e.g., the walls vibrated less, so moved less air on opposite side). Essentially, the bathroom, which was just off a large meeting room, was Taco Bell/Time safe.

View msinc's profile


567 posts in 1115 days

#11 posted 04-19-2018 06:13 PM

Renters have a right to enjoy what they pay for without hearing table saws or compressors and you will never TOTALLY eliminate the noise.

- dhazelton

They absolutely do have that right…they also have the right to get out. Right now. I usually tell mine that I am not going to be upset if they decide to get lost. This is especially true when they believe the “no pets” clause meant only for the first two weeks. Or that keeping the grass cut means once a year whether it needs it or not. Most, not all, have a reason why they have no choice but to rent.

View Arch94's profile


6 posts in 1007 days

#12 posted 04-19-2018 07:53 PM


Here are a couple variables that impact sound transmission:
Mass – More mass = more material sound waves must move and move thru to get to the adjoining space. Best way to do this is a concrete topping slab and/or a ceiling with multiple layers of gyp board.
Stiffness – Decreasing the stiffness of an assembly will increase the amount of sound deadening. Not something I recommend in a floor/ceiling assembly
Dampening – dissipating sound energy, think shock absorber. Use sound-deadening under-layments, carpet w/ pad and/or attached the ceiling to the joists with resilient channels (Google “RC-1 channels”).
Cavity depth – deeper the cavity the more sound transmission loss, especially if it’s filled with insulation
Cavity absorption – Fiberglass batt or mineral fiber insulation in the cavity. Fill the joist cavity but don’t pack it.

A couple other issues to be aware of. Do not punch any holes in the ceiling membrane if you can help it, and seal the perimeter. Sound will find any little hole and leak thru. If you insulate the floor cavity and the garage is unheated, you may need to look at installing a vapor barrier. Also that floor/ceiling assembly between the garage and living unit will probably need to be fire rated. Check with the local Building Dept. I’m not well versed on the residential side of the building code.

Send me a PM if you want any more info.

-- I don't have ducks, I don't have rows. I have squirrels, and they're off their medication.

View Fresch's profile


460 posts in 2532 days

#13 posted 04-19-2018 07:57 PM

They also make sound channel you install before sheet rocking. You may need too to a commercial supply house not the borg.

View dhazelton's profile


2839 posts in 2908 days

#14 posted 04-19-2018 08:08 PM

I was just pointing out an issue. If you want to have a rental space for income you should be prepared to be a landlord. And if you’ll be sharing the same space expect some friction from them or you. You can be a tough guy like above and say ‘get out’ but if you do the whole process legally with permits and rental agreements that’s easier said than done. You could also decide it’s best to live in the garage apartment yourself and rent the house. I personally wouldn’t want the headache or insurance hassles of either scenario.

View that1guy's profile


10 posts in 649 days

#15 posted 04-19-2018 08:27 PM

Isolating all the vibrations is one of the most important things with sound proofing. I’ve seen home theater rooms that are a separate room on springs inside of a room. Crazy cool but way too much money lol

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