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Using quickrete to sound proof walls? Answered

After reading online I thought about an easy cheap alternative to lessen the noise in my garage studio room from escaping to the outside world.  After the new construction the smaller space seems to echo much more than before, thus the need for more soundproofing/deadening.  I though about building forms with plywood backing and filling them with readymix quickrete with wire mesh on top.  After fastening the frames onto the brakets I have that will be firmly fastened to the wall in staggered pattern drywall and carpet padding will be applied on top of the plywood side of the form that would be facing toward the middle of the room thus creating a second relatively thick layer of sound deadening with roughly 1 1/2 inched of dead air space trapped between the outer and inner layer walls.  Has anyone ever tried this?   Thoughts, comments, suggestions welcome. 

To clarify:  From outside to inside I would have: 

Siding - Standard Wrap and OSB - Stud- Moisture Barrier- Insulation - 5/8 Drywall - 1 1/2 inches of dead air space - Wire mesh side of concrete forms 1 in thick - concrete- plywood backing side of form - carpet padding - drywall - carpet  


Don't waste your money on 1" of conc. 1" is not thick enough to block sound properly. A better use of the money would be more fiber sound deadening. Or a double wall system where the inner surface was installed on one set of studs and the outter wall surface was installed on another set of studs and the different sets of studs didn't touch. That way sound would not be passed thru the wall by conduction. You could then lace sound batts thru the walls for more sound control. Sound batts are denser than temperature batts. They are a little harder to find. If you can cover your walls with foam rubber then carpet you can make a very quiet and durable wall. Dont forget the ceiling also.

What if I made the walls to be 2 in thick of concrete instead?
I really don't want to waste the space to construct the double wall (it has been on the table for a while as a possible "go") and quickrete is cheap and building forms for the walls would be relatively simple. I was just curious if an inch or so would be enough as I know in rooms that I have tiled with backboard and ceramic tile the noise is reduced considerable from leaking out into other rooms.
Thanks for all your help,

2" would probably help. But I'm in construction and building cast in place wall like that is going to be a huge effort. Much more work than you expect. You can build a double wall by adding 2". The new studs can be placed between the existing studs but offset by an inch or so. The idea is to have the drywall/sheathing on each face not connected to the same studs thereby not having a direct path thru the wall. They can be connected to the same plate top and bottom. The plates are stiff enough that little sound will transfer. Be sure to seal at the floor level.

Thank you so much for your help!

As far as the sound batts...
This may be a possibility to help deaden the area above the ceiling in the attic portion of our garage.

Thank you!

You have more than one option here. Using another layer of 5/8 Drywall will give you added soundproofing without any other construction. Another option is to purchase Drywall that is designed for soundproofing applications (check your local home improvement store).

If after your soundproofing, you experience an echo (caused in part to a rather empty room), you need something on the wall that works to "absorb" the sound versus allowing it to bounce off as an echo. So, what you'll need is soundproofing foam that has a surface area like the inside of an egg carton. This is used mainly in sound proof studios to minimize the echo, but can be purchased through some retailers.


You commented to someone that you find it "louder than before"... Can you clarify what you mean? How was the room before and what have you added or taken out? I got the impression that you hadn't done anything yet...

Also, it would be helpful to see some photos. There are a number of ways that sound can escape from a room, and by seeing some images (all four walls, ceiling, floor etc), along with anything you know about the construction would help too.

Have you put your equipment/furnishings back into the studio after the renovations? An empty room always echoes quite a bit.

No... its the sound outside of the garage seems louder now than before!
The sound inside will be treated with acoustical ceiling tiles and bass absorption traps and the like... it is the sound that is leaking from the room that I have the problem with.

Really old fashioned idea is to fix egg boxes on the walls and doors.

I can't tell if your wanting to stop sound going out or coming in.

Check out anechoic chamber.