Soundproofing

[Peter Murphy]

G'Day Folks

I'm in the process of trying to establish a workshop, i am converting a 2 car garage space. It has brick walls tin roof and bifold floor to ceiling metal door, which spans the double car width.
I have done some research and sort some opinions on this and other forums,
about stopping the noise the machinery will generate escaping.
The consensus of opinion so far, has been that due to the brick walls and the fact they are "cut into" a hill, and therefore surrounded on 2 sides by fill ( upto half there height off the floor) that most of the noise will be generated through the metal front door and and metal roof.
For this reason i will be building a wooden frame, floor to ceiling doors (soundproofed) internal to the existing doors. The door problem should be eliminated.
However the roof is a bit more tricky, i can apply (double) thickness gyprock sheeting with insulation (thermal and acoustic) between the roof joists. But the other problem the roof presents is that it makes the shop very dark. I was hoping to overcome that problem with skylights, 2 to be exact.
Of course they then recreate the original soundproofing problem. ( back to square one).
So finally, the question........Can the skylights be fitted with internal shutters, that is internal to the roofline , that might be powered and remotely operated. That will allow natural light and also have some dampening effect on machinery noise???
Sorry for being so long winded, i needed to paint as complete a picture as possible. Any opinions, ideas would be appreciated.


Thanks 'The Woodsman'

[Maurice Ungaro]

Woody, I think you'll find that a couple of skylights will not pose that much of a sound problem. As for insulating the roof, have you considered a spray foam product such as Isonene (sp.?)? It offers incredible insulation, great sound proofing,and does not require a construction project.

[Mike Olson]

There is something called QuietRock which is a sound deadening 4x8 sheet similar to drywall.

skylights probably won't let too much noise out, but if you are concerned there is a reflective tube product "solatube" that you might be able to use. give it a good bend to deflect the soundwaves and it should be good.

[ian maybury]

Some thoughts.

It can happen that sound is very good at finding gaps to get out so to speak, but it's not always that predictable I think. It's not always possible, but there's probably a lot to be said for taking these jobs one step at a time and reviewing the results at each stage - rather than hitting it all in one go.

Harder/springier materials may be most inclined to propagate noise.

Machines and rotating machinery like fans often make a lot of noise as a result of even not very obvious vibration propagating into the structure of the building. I'm not sure if there's anything to be gained in the case of typical woodworking machines, but fans and the like can benefit very noticeably from being soft mounted. (using resilient mountings - even the likes of sheet foam)

ian

[Daniel Berlin]

G'Day Folks

I'm in the process of trying to establish a workshop, i am converting a 2 car garage space. It has brick walls tin roof and bifold floor to ceiling metal door, which spans the double car width.
I have done some research and sort some opinions on this and other forums,
about stopping the noise the machinery will generate escaping.
The consensus of opinion so far, has been that due to the brick walls and the fact they are "cut into" a hill, and therefore surrounded on 2 sides by fill ( upto half there height off the floor) that most of the noise will be generated through the metal front door and and metal roof.
For this reason i will be building a wooden frame, floor to ceiling doors (soundproofed) internal to the existing doors. The door problem should be eliminated.
However the roof is a bit more tricky, i can apply (double) thickness gyprock sheeting with insulation (thermal and acoustic) between the roof joists. But the other problem the roof presents is that it makes the shop very dark. I was hoping to overcome that problem with skylights, 2 to be exact.
Of course they then recreate the original soundproofing problem. ( back to square one).
So finally, the question........Can the skylights be fitted with internal shutters, that is internal to the roofline , that might be powered and remotely operated. That will allow natural light and also have some dampening effect on machinery noise???
Sorry for being so long winded, i needed to paint as complete a picture as possible. Any opinions, ideas would be appreciated.


Thanks 'The Woodsman'






The only thing to add to your roof idea (rockwool works well for what you want to do for insulation, closed cell foam would be better insulation wise but worse soundproofing wise) is to make sure you decouple the gyprock sandwitch you are making from the joists using sound clips or something.
As for lighting, I have to admit, this is a problem I would simply solve by hanging more lights, and using bulbs that are daylight temperature or whatever. That said, the skylight won't be all that bad for soundproofing as long as it is at least double glazed (though the sound transmission will get worse as the gases inside escape).

In any case, let me ask a more basic question: Who are you soundproofing for? Is it that you think your neighbors will complain, or you want to work inside while family is in other nearby rooms, or what?

The first is an easier problem than the second (IE if you want someone 20 feet away in a different building structure to not hear much, that's a lot easier than trying to reduce sound transmission enough that your wife in the kitchen next door doesn't complain).

It's certainly possible to achieve the second, but it may require more concerted engineering efforts.

[Mark Denovich]

I've done a fair amount of research on this topic. There is a lot of "hocus pocus", snake-oil, sound killing voodoo BS out there. Unfortunately, there is no silver bullet. Real test data shows the three strategies that work (in conjunction): add mass, decouple, and dampen.

A few points I've come away with:

There isn't much difference between insulation (the cheap pink stuff is pretty much the same) and it doesn't do all that much (but it's cheap, so you might as well.)

Adding layers of heavy drywall works (adding mass) Squirting Green Glue (one of the very few specialty products that appears to live up to the hype) between a pair of sheets works even better (dampening) Cost is about $.50/sqft. Wether or not you use their stuff, their website is a good source of info: http://www.greengluecompany.com/technicallibrary.php

Decoupling is the real answer, but it can be tricky. It's easy to short circuit the decoupling (accidentally tying the two walls together with errant screws) and can also be undone by pipes/ducts/other room penetrating structures. Basically, build a room with in a room, or a double studded wall, or use some sort of rubber isolated metal channel, which you then screw your drywall onto. All work, all fairly expensive/involved.