Noise dampening for you shop?

Has anyone found good products for noise dampening the sound in your shop? The new house we’ve purchased has a nice big garage / shop however there is an apartment above. We’d like to start renting it out but I’m afraid to cause issues with loud shop tools bothering the tennant. The other alternative is to move the shop into my basement but that could still cause similar issues.

Anyone have good suggestions to keep sound down? I’m thinking acoustic foam on the walls or something similar but I’ll need to keep the area clean from sawdust to keep it effective.

There are many techniques for sound suppression.

I’d HIGHLY suggest doing a Google search on free and inexpensive sound suppression.

That said, you’re right spray foam as well as insulation are a good start. Moving blankets and other sound absorbing material are also another. And believe it or not egg crates work well at defusing sound.

Basically you want to make it so the sound waves don’t travel intact.

Now I mention inexpensive ways as there are many very expensive ones but doing the basics should have a huge impact and get you a great start.

Personally I have a sound meter app on my phone so I’d start taking a reading of how things are now. I’d then make a note in a notebook and then do the next thing. Take another reading. Then the next thing, etc.

As you do this you’ll see and hear how much progress you’re making. Plus it’ll be cool to actually understand the impact of each thing you do.

Finally, keep in mind that sound isn’t linear. So one dB change is much greater at first then later on. So at some point you’re chasing small improvements with more and more expensive and involved techniques. Hence my suggestion on an approach o tackle the low hanging fruit first.

Someone on the forum had posted a link to this awhile back, sorry can’t remember the user, but it looked pretty easy and cost effective.

It seems that apartment is now empty so I’d start by turning on as many devices as you’re likely to have running at once and going into that space to get a baseline for what the noise level might actually be. Depending on the current flooring, perhaps you might consider upgrades which may both raise the potential rent $$$ as well as contribute to lowering the sound level?

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I’d also do each individually as some of the sounds can cancel out the harmonics from others.

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I’m with Paul on determining the level of noise first, and considering upgrades that may improve rental value.

Remember that keeping noise contained, and having good acoustics inside a container are 2 separate goals that require different approaches to achieve. Egg crates, foam baffles, etc are usually features to improve internal acoustics, but do little to contain the noise from escaping (in fact ideal acoustics have no reflection, so the noise goes straight out and never returns… maximizing complaints from upstairs).

This is very different than containing the noise within a room. Once sonic energy is released inside the container, that energy must be transferred to heat within the container, or it will escape. The most common method for trapping noise in a room is doubling up the layers of drywall. For a situation like you describe, the apartment above would be much quieter after simply adding add a second layer of 5/8" drywall to the ceiling of your shop (noise escaping the side walls could resonate as well… you may need to double up the walls if that happens). You don’t necessarily have to tape the second layer, as your garage is likely already built to fire code (just have to spot the nails). However most folks I’ve seen doing this often use a notch trowel to apply a layer of hotmud between, which sort of glues the layers together when it is screwed off (careful of your pot life… gotta be kinda quick on the screw gun). I would not use regular joint compound on it, since it may be trapped between to moisture barriers later if it gets painted. If you have lots of cash to get rid of on it, you could stick dynamat between the layers instead. Also, depending on your aesthetic goals, untaped drywall may not be cool; that could get expensive if you aren’t doing it yourself.

Also, since the building is new, it should already have insulation between the garage (outside space WRT building code) and the living areas above. So if your home was properly constructed, you wouldn’t have to do that if it were needed. However, if you end up needing more than insulation and double drywall, it would be good to know this before hanging that second layer of drywall. Otherwise it all would have to get ripped out and replaced to access the joist bays above (if you needed to add more hardcore damping materials up there).

This is just my $.02… I work in construction and see this done all the time on theater rooms and such. Double drywall always works very well.

This.

A 3dB change represents halving the amount of sound energy, so that’s a HUGE improvement. Another 3dB means a quarter, and so on.

My house is old construction, plaster is a good noise shield, and I can run my CNC in the basement while my mother is sleeping. That said, I can still hear my 3D printer (MUCH less noisy) on the main floor. Never been on the main floor while the CNC is running though.

Sprayfoam in the rafters works well. My basement is set up as a suite, but since my friend moved out, it’s now my workshop/office. There is also an acoustic mat material that you can buy if you’re re-doing the ceiling that dampens noise well. If you do sprayfoam in the rafters, make sure that you leave some sort of provision for cables and wires, or keep an air gap (Which also works as a sound barrier.)

Check your local home improvement stores for sound insulation, too. You may be surprised at what they have.

Oh, and 100%, keep track of dB levels outside of the work area. Every 3dB is taking out 1/2. 10dB is taking out 90%

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Apartment is brand new, no one has lived in it yet and it’s completely finished.

Thanks for the feedback. The property does have another shed but it has no power and is quite old. Would be a bit annoying to heat a second out building in the winter when the garage already has to be heated but that is an option.

Well then do some measuring and see how things are. If you’re lucky they may be better than you think. Worse case you come up with a plan and figure out how to make things work.

I’m curious as to how your soundproofing is coming along? I’ll be building an enclosure around my new project mostly for dust control and secondly for sound, as to not piss off the neighbors…

I haven’t actually taken possession of the property, we close in a few weeks. This post was to solicite feedback so I can decide what my options are.

Well, good luck on the closing! I’m planning on building, basically a 2x3 and plywood room around it with insulation and foam panels on the inside. It will be tall enough to comfortable fit with room for lighting. Also, down to the floor to enclose vacuum. Did something similar for compressors at work a while back and worked well. Will se how it goes with the higher pitched router motor and vacuum.

Please keep us posted. As you can see several of us are interested in these things.

Personally, I’m interested in the approach you take and what you decide.