Author Topic: Concrete between the studs?  (Read 4670 times)

Brent Miller

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Concrete between the studs?
« on: January 23, 2002, 07:49:40 PM »
My bass is intense, the exterior walls of my house are lame, and my neighbors are pissed. If masonry is the best soundproofing material why not simply rip off the interior sheet rock, remove the lame R-11 insulation that does not block bass at all, and fill the space with concrete? Tar paper (black roofing paper) or
Duroc/Wonderboard could be used to keep the concrete from coming in contact with any untreated wood. Filling between the studs could be done over 4 or 5 days only filling a foot or two at a time so that the weight of the wet concrete would not break the 1" foil covered rigid foam insulation and cedar siding on the exterior side of the studs. A strip of plywood could be used as a form wall on the inside being moved up at the time of each additional fill. Lag bolts could be screwed into the sides of the studs to better couple the concrete to the stud giving the whole wall better integrity. The wet concrete would encase the lag bolt and dry that way. This would essentially be a concrete wall with 2x4 studs every 16 inches. Resilient channel or sound clips could then be mounted to the studs and the interior wall could be built with the standard procedures and fine materials found on your site. The room might be a little colder in the winter but the 1" rigid foam would still be on the outside of the wall and I have a nice gas insert in the room anyway. The only thing I'm not sure about is if there would be any kind of moisture problem. The floor is concrete slab so not problem there and I'm planning on using the sound clips and double sheet rock on the ceiling. What are your thoughts on this? Have you heard of anybody else doing this? Do you think the concrete wall in conjunction with a floating wall will effectively block low bass frequencies or is it more effort than it is worth? Bricks and mortar could be used as well but probably wouldn’t be as solid. On your "Soundproofing a garage" page you mention filling the space completely with Duroc or Wonder board. That doesn't sound as solid as poured concrete or bricks and mortar either but what do I know? Any comments/suggestions on this would be greatly appreciated.


sam hobbs

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Re: Concrete between the studs?
« Reply #1 on: March 08, 2002, 03:14:21 AM »
I'm think your concept is good but implementation will be very difficult. Wet concrete contains loose gray water that spills through every crack and seam.  Plus, you must consider the weight of the concrete pulling downward on the lag bolts and compressing the treated wood plate at the bottom of the wall. The wall would be so heavy, it could topple over as there is probably nothing at the top of the wall to prevent the top from tilting either outward or inward (the attachment of the plate to the floor is likely not strong enough to counteract the weight of the top of the wall). Also compression could cause the wall studs to separate from the plate, and the concrete moisture could make them twist and pull away from the outside siding.  Humidity condensing on the concrete inside the wall cavity invites mold and mildew.
Consider using 4" thick  hollow core blocks and setting them with mortar for much of the same effect without the mess, moisture and weight.
: My bass is intense, the exterior walls of my house are lame, and my neighbors are pissed. If masonry is the best soundproofing material why not simply rip off the interior sheet rock, remove the lame R-11 insulation that does not block bass at all, and fill the space with concrete? Tar paper (black roofing paper) or
: Duroc/Wonderboard could be used to keep the concrete from coming in contact with any untreated wood. Filling between the studs could be done over 4 or 5 days only filling a foot or two at a time so that the weight of the wet concrete would not break the 1" foil covered rigid foam insulation and cedar siding on the exterior side of the studs. A strip of plywood could be used as a form wall on the inside being moved up at the time of each additional fill. Lag bolts could be screwed into the sides of the studs to better couple the concrete to the stud giving the whole wall better integrity. The wet concrete would encase the lag bolt and dry that way. This would essentially be a concrete wall with 2x4 studs every 16 inches. Resilient channel or sound clips could then be mounted to the studs and the interior wall could be built with the standard procedures and fine materials found on your site. The room might be a little colder in the winter but the 1" rigid foam would still be on the outside of the wall and I have a nice gas insert in the room anyway. The only thing I'm not sure about is if there would be any kind of moisture problem. The floor is concrete slab so not problem there and I'm planning on using the sound clips and double sheet rock on the ceiling. What are your thoughts on this? Have you heard of anybody else doing this? Do you think the concrete wall in conjunction with a floating wall will effectively block low bass frequencies or is it more effort than it is worth? Bricks and mortar could be used as well but probably wouldn’t be as solid. On your "Soundproofing a garage" page you mention filling the space completely with Duroc or Wonder board. That doesn't sound as solid as poured concrete or bricks and mortar either but what do I know? Any comments/suggestions on this would be greatly appreciated.