# Soundproofing wall betwen Garage/shop and house



## CovenantCreations (Jun 15, 2010)

Ok, this isn't really a skill share, but I didnt know where else to put it. I am looking of r a way to soundproof the wall between my new workshop (24×24) garage which is attached to our house. I plan on insulating the wall very well and sheetrocking it. But then I goth this idea, and I dont know if it would work or not thats why I am on here asking. Putting up some sort of metal siding on the wall, such as what they use for siding buildings and such. I have a ton of the galvanized stuff laying around form old sheds I tore down, and I was thinking this may deflect the sound back into the room. Maybe not? Whats your say on this?


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## SnowyRiver (Nov 14, 2008)

If you are thinking about putting the steel up on the wall against the house, I would think a sound deading insullation, and certainly regular insulation would work better. I would think steel would reflect the sound both ways and possibly cause vibrations. My shop is the same size as yours and it has a wall against the house also. I used regular insulation. Instead of sheetrock, I insulated the wall, then put 3/4 inch plywood on the wall, covered by 1/2 inch pine beaded paneling. This worked well to deaden the sound and looks nice. I put the plywood and paneling around the entire room so I could just screw cabinets and shelves anywhere with out using anchors or hitting studs.

You can see it in my shop pictures.


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## mnguy (Feb 4, 2009)

First, building code requires a fire barrier between the garage and the house (I imagine your shop qualifies as a 'garage' in the code), which means a fire-rated drywall, usually 5/8" with taped seams. You can put plywood or other flammable materials over this (I think). There are things called sound isolation channels that are designed to space the drywall away from the studs and to minimize sound transmission. If it was me (my shop is in the basement), I'd insulate, sound isolation channels, fire rated drywall, decorative mounting surface (plywood, beadboard, etc.).


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## stratiA (Feb 26, 2009)

I needed to soundproof my daughters upstairs bedroom from my upstairs tenants kitchen in my 110 year old home. The upstairs tenants happen to be rock musicians. They don't do alot of practicing while home out of respect to me and my 3 year old, but they do sometimes. I found a sound absorbing drywall called quiet rock from quiet solutions. It is absolutely amazing stuff. I only used it on the 2 common wall between rooms. To try to really sound proof the room I used a combination of homasote and quiet rock over existing drywall. My daughters room has become the quietest room in the house. Even during loud practice with heavy bass it works amazingly. The bad news is it is expensive and it is amazingly heavy. If you need just a couple of wall this is the way to go. Mike Holmes from Holmes on homes, the Canadian DIY show actually used it on an episode once.


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## stratiA (Feb 26, 2009)

Ironically after I wrote this post and entered it, I noticed an ad for Quiet Rock at the bottom of the screen.


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## CovenantCreations (Jun 15, 2010)

Anyone ever use corkboard to absorb sound? Thanks for all the input so far.


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## versa (Oct 27, 2009)

Metal would resonate making the noise worse.
Corkboard would be expensive and not do anything. Same with fibreglass insulation.

The problem is sound will find any little hole and flow thru it. So if you don't insulate all 4 walls and the ceiling it won't do much. That said…

Mass would be the cheapest, easiest, and most effective method to reduce noise. Double drywall the adjoining wall will add a bit of noise blocking. Squirting some green glue in between the layers will help a bit more for a bit more cost. The quietrock would cost a lot more but do quite a bit more sound blocking. You could go farther but the law of diminishing returns makes it impractical without doing more total enclosing of the sound.

Just keep in mind the loud noises of certain tools (planer, table saw, belt sander etc) makes it nearly impossible to be 'sound proof' you can only lower the volume of the noise getting thru with increasing levels of cost associated with that.

The ultimate would be to build a room within a room with new studs, walls, ceiling and floating floor with 6 inch thick walls that have alternating studs (so the inside and outside drywall don't share framing members to pass vibrations) with fibreglass weaved between the studs with mass loaded vinyl hanging freely in the cavity with quiet rock on both sides of the wall+ ceiling. With two heavy outside doors with gaskets on all sides to ensure a good air seal in an airlock configuration. Any wall infiltration should be properly gasketed ( lighting, electrical sockets, etc. Ventilation should be fibreglass tubing with multiple 90 degree bends to absorb noise. Obviously the time, money, and space restraints make this slightly impractical.

The above is an idealized sound proof room for a home theater, but is applicable to any noise reduction scheme. Parts of the plan can be integrated as time/money/space allows.


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## Lambchop (Aug 19, 2010)

Versa is right on the money. I helped build all the studios for CMT downtown Nashville and here is what I learned from the engineers. Sound actually reverberates through solid materials (i.e- concrete, studs, doors). The more dense and solid the more it can carry the sound. Soft materials tend to absorb the sound and not transfer it on to whatever it's touching. The best thing is to have dead air space in between tweo walls with as little touching as possible in between them. The studio walls were constucted in this order: sound baffle - 5'8" drywall - sound caulking - 5/8" drywall - neopreen (this was a foam tape put on all the studs)- stud - 3" of air space ( then the reverse )- stud - neopreen - drywall - caulk - drywall - sound baffle.

This was the order from one studio into the next. You could fire a gun and not hear it in the next one. Of course the floors were built on these super expensive sound absorbing blocks and had 3 layers of drywall then the plywood.

In your case I probably just build a new insulated wall an inch or two in front of your existing wall and try not to let them touch.

Just passing what I learned. Let us know what you do


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## jeth (Aug 18, 2010)

The soundwave energy that causes materials to vibrate and transmit sound is best reduced when that energy has to pass between materials of different densities and ridgidity. A common way to achieve this is sandwiching a heavy flexible material between two layers of a stiffer material. When the sound hits the outer surface of this "sandwich" the energy is then trying to flex the two stiff sheets whilst the more flexible material in the center absorbs the pressure. They sell a very dense heavy rubberised sheet for this purpose, usually glued between two layers of thick plasterboard, but it is very expensive. Some kind of heavy foam rubber, dense neoprene or similar material is a good replacement, though you would need to be careful about fire regulations. 
The other key factor is isolation, so this wall structure, mounted on studs would want to be floating, decoupled from contact with all other materials that can transmit the energy hitting it into the structure the other side. This can be achieved by sitting the studs themselves on a layer of the same rubbery material used inside the wall structure, done properly everything would be glued in place with a PU foam glue, not even nails or screws to pass those vibrations into the surrounding concrete structure.
As mentioned this is never going to be fully efficient unless all of the inner surfaces of the structure that joins to your house are protected by the floating soundproof layer, as vibrations hitting any unprotected surface will transmit through the structure, but if you do it well to the main wall between the two spaces you should be absorbing enough of the direct sound energy to at least have a considerable effect. Somebody also mentioned how the smallest holes can make the whole thing drastically inefficient, so lots of caulk on all joining surfaces and even ducting for cabling etc should be filled with galss fibre or similar to avopid transmission of sound energy to the other side of your "soundproof" wall.
Another key issue is the air gap between your floating wall and the wall behind, this should be as large as possible and with a little calculation can be made more effective by working out more or less the frequencies of the noise your machines are making and sizing the gap to be a division of the wavelength of the main frequency. The sound will in theory then pass through the floating structure reduced, bounce back from the concrete structure and continue to be cancelled by hitting the sound absorbing layer repeatedely as it bounces back and forth. I am guessing the frequency of most power tools to be in the low hundreds of hertz.. Sound travels at approx. 344 metres per second, so at say 100Hz you have a wave 3.44 metres long, making your air gap say 86cm would be a quater of that wavelength and should increase the effectiveness of your noise reduction, but you are going to lose about a meter of your workspace! You can make it a little smaller and fill some of it with rockwool or glass fibre, making the soundwaves travel a little slower and they then "see" the space as larger than it actually is… But the reality is, you can't kill sound without a lot of mass, using up a lot of space, and spending a fair bit of money.

Do a search on the web for diy soundproofing and you will see various differnet ideas and some more in depth explanations opf the theory. I saw a nice diy studio that used tightly rolled up carpet offcuts between double plaserboard floating walls but the guy was hunting in carpet warehouse skips a long time to get all that free material. Good luck!


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## Mike_C (Aug 11, 2010)

Some quiet rock was used in a building where I work and it is amazing stuff. It was installed between an office and private bathroom and a common area. No one can hear a thing from the office or bathroom anymore, I have done audio and video recordings in the room so I know this stuff works. The only bad thing is that it the common room has a wireless network and the quiet rock does not let it pass through!
In another room we "soundproofed" the shared wall. It was done with multiple layers of homasote and sheetrock with a small space between each layer. It worked well but it added several inches to the wall.


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## Ripthorn (Mar 24, 2010)

I researched acoustics for 6 years in school and designed recording studios and such for a firm in Berlin for a summer.  The thing with room acoustics is that there are a ton of variables, and no single product is going to be your silver bullet, though something like quietrock will come close. One of the oldest, tried and true methods is to simply frame out a second wall that is not mechanically coupled to the wall you want to soundproof. Air is actually one of the best sound insulators we have. So when you have a sound wave that has to go through sheetrock, fiberglass insulation, air, fiberglass insulation, sheetrock and then air again, you have all kinds of sound reduction because of the boundary impedance mismatches. If you want to read more about how to deal with it, I recommend "The Master Handbook of Acoustics" which is only about $30 and written so everyone can understand it. If you were to double wall with double layers of drywall and plenty of insulation inside (but do not completely fill the area between walls) you would see a huge sound reduction.

Of course, if you can afford quietrock, it could save you about 4 inches in the width of your shop. And don't put up the metal, it will reflect back more high frequency energy that will damage hearing quicker.


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## TomHintz (Feb 4, 2009)

I needed to sound-proof my office in our house for video work so had a contractor come in who has done this before. He used loose fiberglass insulation in the bays and two layers of an accoustic drywall. I don't tnhink it was called Quiet Rock but not sure of the name he gave me. Whatever it is, it works great! 
However, I also think that the post regarding fire regulations for a grage wall could be a problem with this type of drywall material. You want to be very sure you are in compliance with the local regs. A viewer from my site did his own wiring and had it almost all in compliance except the location of one box. A fire started elsewhere but his insurance found that illegal (jsut slightly off spec according to the city inspector) box and nixed his coverage altogether.


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## AuroraWoodworks (Nov 6, 2009)

I had some extra foam sill sealer rolls laying around and stapled it to the edge of the studs prior to drywall. It made a huge difference in the walls that had it. After I ran out of sill sealer, I bought a roll of cheap laminate floor underlayment. The sound transfers through the rigid parts of the wall and you need to isolate those connections. FineHomebuilding had an article on sound deading a couple years ago.


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