Soundproofing attached garage

Soundproofing attached garage · 10-01-2009, 11:35 AM

I want to make an attached garage into a workshop. However,
soundproofing is an issue that doesn't seem to have a
satisfactory answer at reasonable cost. Does anyone have
experience in this area?

CarvedTones · 10-01-2009, 11:53 AM

I researched pretty thoroughly to come to the same conclusion. One thing I did find was that you can reduce it significantly by targeting the places that let the most sound through (door, exposed beams, etc) and by trying to deflect or absorb sound where it is generated. I though about getting one of these:

http://www.soundcurtains.com/portabl..._screens.shtml

They aren't cheap, but there are other suppliers. I linked to that one because it has some good examples. That folding 2 panel one would be easy to pull out and position on the house side of a machine before cutting.

Alan in Little Washington · 10-01-2009, 12:01 PM

If your studs are open on the garage side, the best solution is to widen the sole and top plates, add a set of staggered offset studs, insulation batts (woven, horizontally between studs), and drywall (maybe two layers of sound rated drywall.) That should do the trick.

The offset studs prevent vibration from being transmitted to the inside wall.

gfernandez · 10-01-2009, 12:35 PM

Dennis,
I am in the process of completing my basement workshop and have spent countless hours researching soundproofing.

I'll give you the short version of what I did, but if you want more information, please feel free to send me a pm.
I found the best bang for your buck to be a product called green glue. It is a viscoelastic caulk that is placed between 2 sheets of sheetrock. Here is their website: http://www.greengluecompany.com/

You basically put up 1 layer of sheetrock, apply green glue and put up another layer of sheetrock, basically making a sandwich with this stuff in the middle. I also used exterior doors with weatherstripping for all my doors leading out of the workshop, including closets, mechanical room.

For the ceiling (not sure if this is an issue for you), I used isomax sound isolation clips on the joists, with hat channel supporting 2 5/8" sheets of sheetrock and green glue.

http://www.soundisolationcompany.com...s/walls/clips/

I bought all my material from Jodie (spelling?) at sound isolation company because he was very knowledgeable, was willing to spend time on the phone with me even after my 999th question, and I like to support local companies. He also had very good pricing on his products.

This may sound like overkill, but since my shop is directly below the kitchen, I was willing to pay a little more to make sure I did not have issues with my soundproofing later.

If you read some of the technical papers on the green glue website, it will give you a good idea of what sort of STC rating you can expect with different scenarios like 2 sheets of sheetrock, building an interior wall, etc.

But the most important part is, of course, how does it work? The other day I fired up my dewalt planer for the first time in the new shop to plane some walnut for a neighbor. My wife was in the kitchen, directly above the shop, and later told me it sounded like someone was using a hairdryer in the bathroom with the door closed. It also passed the most important test which was it did not wake my 3 kids from their nap.

Gonzalo

CarvedTones · 10-01-2009, 12:41 PM

We should probably clarify what "reasonable cost" is.

Alan, he is in Orange County, so I can't be sure, but most of the "non rural" counties have codes requiring that the wall from an attached garage to living space be insulated and closed up. So what made this idea unappealing to me was the cost of doing it on an already insulated and closed wall and the prospect of it having to be inspected (and pass). It doesn't make it non workable, it just made the cost not reasonable for me.

EDIT - I see Gonzalo posted while I was typing. He has a very nice setup, but made a fairly significant investment to get it. I wish I had one like it! So, again, the question is what reasonable means to Woodfish.

Bas · 10-01-2009, 12:54 PM

I have been looking at an insulation material called UltraTouch, made from recycled jeans. Apparently, it has really good soundproofing options. I'm considering using it for insulating the closet that will house my dust collector. If your garage currently has open studs, or you plan to rip down the drywall anyway to run power, this might be a good option.

http://www.bjgreeninsulation.com/about.html

Plus, insulating the garage will also help with heating & cooling.

gfernandez · 10-01-2009, 02:41 PM

Originally Posted by Bas

I have been looking at an insulation material called UltraTouch, made from recycled jeans. Apparently, it has really good soundproofing options. I'm considering using it for insulating the closet that will house my dust collector. If your garage currently has open studs, or you plan to rip down the drywall anyway to run power, this might be a good option.

http://www.bjgreeninsulation.com/about.html

Plus, insulating the garage will also help with heating & cooling.

Bas,
Looks interesting, what sort of STC rating can you get from this compared to regular insulation?

scsmith42 · 10-01-2009, 03:06 PM

In addition to Gonzalo's recommendation, use open cell spray foam insulation in your walls behind the sheetrock.

You should end up with some outstanding soundproofing.

gfernandez · 10-01-2009, 04:32 PM

Here are some interesting statistics on sound isolation.

http://www.greengluecompany.com/tran...nLossTests.php

Dragon · 10-01-2009, 09:51 PM

It may take some time and a little inventive thinking but has anyone thought about canvassing your local business and industry entities for their discarded packaging materials? I work for a company here in Lincolnton that tosses serious quantities of soft foam and styrofoam every day. I'm sure there are lots of places around that throw this stuff away by the ton. I'd collect it up and store it for future use but my available space doesn't allow for that much pack-rating. Just an idea for consideration if you really want to work on the cheap.

I'm not much of an environmentalist but I see a lot of waste that could be exploited by someone with the ability to do so.

jlwest · 10-02-2009, 01:12 PM

The easiest and cheapest way to soundproof is to add mass such as double sheet rock (5/

. The more mass the more sound deading. Of course adding foam insulation helps also by adding mass. The main thing is to block and the sound waves and avoid transferring them into other forms that can trasmit through your studs and things. Sound studios use foam inside to avoid echos and other vibrations. Of course hard flat walls in your shop may increase the sound levels in the shop.

Jeff

gfernandez · 10-02-2009, 01:34 PM

Hate to disagree, but adding more sheetrock, in an dof itself, does not add that much more soundproofing.

Example:
Your typical 2 x 4 wall with 1 layer of 5/8" sheetrock on either side give you an STC rating around 40. Increasing this to 2 layers of 5/8" sheetrock on one side and keeping 1 layer on the other gets you up to a 42. 2 layers of 5/8" on both sides goes up to a rating of 44.

Using MLV (mass loaded vinyl) sandwiched between 2 sheets of 1/2" sheetrock on 1 side, 1/2" sheetrock on the other gets you to an STC rating of 44.

Using a product like greenglue with 2 sheets of 5/8" on 1 side and 1 layer of 5/8 sheetrock on the other gets you an STC rating of 52.

CarvedTones · 10-02-2009, 02:03 PM

Gonzalo,

These numbers baffle me (pun intended

). Take a look at the chart at the bottom of this page on the portable baffles:

http://www.soundseal.com/pdfs/ss-103-72res.pdf

They seem rediculously low on the STC compared to what you posted, unless it is additive (like having that panel between the machine and the wall will have the STC of the wall plus the STC of the panel). Is that how it works or am I missing something? I have been watching for a deal on panels.

A couple of things I was told that I are along the lines of what Jeff said... I have an exposed steel I Beam in the garage and I was told that simply encasing it in sheetrock would significantly reduce the amount of sound that resonated through the house. Someone else told me that very flat walls (slick paneling) will reflect sound and that with the garage door open, less sound would get into the house. That makes some sense, though it doesn't seem like it would be all that significant. When you raise the doors, any sound waves that would have echoed off them will escape instead.

Cuprousworks · 10-02-2009, 02:17 PM

One inexpensive idea that I haven't seen mentioned is to staple sill sealer to the studs prior to screwing in drywall. The rationale may be along the lines that it's an insulator to keep drywall noise from being transmitted through the studs?

I can not say for sure if this works - I am doing this now in a stud wall shared with my shop. I can say that it's pretty cheap, so I'm not out much if it doesn't produce.

In commercial office environments I've seen them stagger the drywall joints and insulate the stud cavities, and of course, use 5/8" drywall. That probably passes for some office noise reduction with minimal expense. For my shop I staggered the 2x4 studs on 2x6 plates, insulated and then staggered the drywall joints. The costs of buying the extra studs to stagger may be as much as some of the sound deadening solutions that I've read here. The combination of gluing an extra sheet of drywall (staggering the joints) with green glue might be the most cost effective. It would be easy to add box extenders to the electrical boxes, on a wall with no windows it would be fast!
Mike

jlwest · 10-02-2009, 02:31 PM

Ganzalo,
I don't think we are disagreeing. I was going with less cost and ease of installation. Green Glue may be great stuff but it cost money and I could see it being difficult to work with for us do it yourself types. You still need the mass to block sound waves. I believe dbA is a logrithmic scale so going from a 40 to a 42 equals twice as much sound deading. Of course going from a 42 to a 52 is 10 times as much.

Jeff