"Quiet Zone"
- Thread starter Amped
- Start date
knightfly
GrouchyOldFartOnBatteries
There is a floor-plan type view of staggered stud construction here-
http://www.homer.com.au/phpBB2/viewtopic.php?t=328
scroll down to June 8, there are a couple of drawings (one is just a close-up of corner construction)
Basically, you use 2x6's for top and bottom framing (Plates and caps) then, you put the outer studs (2x4's) on 24" centers, flush with the outer edge of the 2x6 - then, you move over approximately 12", and put the inside studs on 24" centers, but flush with the INNER edge of the 2x6. You need to do the corners just as I've drawn them, and put the second CAP 2x6 on so it overlaps the first one for strength. You weave R-19 insulation (tightly) through the studs, then put your choice of panels on inside and out (insulation is easier if you stand these frames up BEFORE you sheath them, but you'll have to put a temporary diagonal brace on the frame to keep it from twisting)
The point of staggered stud walls is this: the outer sheath is supported by ONLY the outer studs, and likewise for the INNER sheath. The only place these two leaves are coupled tightly, is at the bottom and top of the wall. This isn't ideal, but is very strong construction and improves on wall performance markedly over having both sheaths firmly connected to the same studs.
The use of RC is, at this point in my (ever-continuing) education, optional. It MAY help STC, but at the expense of MTC, which covers lower frequencies. Since lows are the hardest to control, MTC is a more valid (but less common) measurement.
Hope that helped - if you need more info, holler... steve
http://www.homer.com.au/phpBB2/viewtopic.php?t=328
scroll down to June 8, there are a couple of drawings (one is just a close-up of corner construction)
Basically, you use 2x6's for top and bottom framing (Plates and caps) then, you put the outer studs (2x4's) on 24" centers, flush with the outer edge of the 2x6 - then, you move over approximately 12", and put the inside studs on 24" centers, but flush with the INNER edge of the 2x6. You need to do the corners just as I've drawn them, and put the second CAP 2x6 on so it overlaps the first one for strength. You weave R-19 insulation (tightly) through the studs, then put your choice of panels on inside and out (insulation is easier if you stand these frames up BEFORE you sheath them, but you'll have to put a temporary diagonal brace on the frame to keep it from twisting)
The point of staggered stud walls is this: the outer sheath is supported by ONLY the outer studs, and likewise for the INNER sheath. The only place these two leaves are coupled tightly, is at the bottom and top of the wall. This isn't ideal, but is very strong construction and improves on wall performance markedly over having both sheaths firmly connected to the same studs.
The use of RC is, at this point in my (ever-continuing) education, optional. It MAY help STC, but at the expense of MTC, which covers lower frequencies. Since lows are the hardest to control, MTC is a more valid (but less common) measurement.
Hope that helped - if you need more info, holler... steve
Amped
New member
Steve, believe it or not, that made perfect sense to me, in fact, as I was pondering the initial "staggered stud" post, I imagined that this was what you were refering to. The only problem I can forsee is getting it past the building inspector, remember, this is supposed to be a "portable storage builiding" only, so Im not sure if he will be inclined to ask "why?". Any other ways to isolate the inside from the outside?
knightfly
GrouchyOldFartOnBatteries
Yeah, just build it with open studs/standard 2x4's - then, when you can't see him smiling any more, build the inner walls the same way (but backward) - he probably won't mind two layers on the outer studs, that would keep you from having to insert sheet rock pieces between the studs on the outer wall from the inside.
That would actually give you BETTER sound proofing, but cost a little more (not much) because you'd have a true double-wall approach... Steve
That would actually give you BETTER sound proofing, but cost a little more (not much) because you'd have a true double-wall approach... Steve
Amped
New member
Ok, the project is slated to begin Monday the 7th, Im pretty comfortable with the design so far, Im confronted with one more obsticle, keeping the sound from escaping through the window A/C unit. Ive considered building a "louver" type of aparatis to place over the exhaust side of the A/C unit to direct the sound to the ground as opposed to blasting straight out. Are there ant other realistic approaches?
Thanks,
Jim
Thanks,
Jim
knightfly
GrouchyOldFartOnBatteries
"Are there ant other realistic approaches?" -
Gee, I LOVE these last-minute bombs... First, what you suggested isn't a realistic approach, so we're still looking for the FIRST realistic approach...
Window style AC units have about the same sound attenuation as a double layer of Saran Wrap - putting louvers over one to direct sound toward the ground won't accomplish anything more than giving you something to build that doesn't work.
Unfortunately, from what I've seen there doesn't seem to be a practical way to use that type of AC unit in a studio, short of turning it up to 11, freezing the room, then shutting off the AC and plugging the hole with a MASSIVE plug and recording til it gets too warm, then repeating the process.
What you need is a split-type unit, and to add some multi-turn, large cross-sectioned ducts for both inlet and outlet, that are isolated from each other and absorbed at all turns in order to make up for the fact that you just put two holes in construction you worked very hard to make airtight.
Here is a thread that may help a little -
http://www.recording.org/ubb/ultimatebb.php?ubb=get_topic;f=34;t=000466
I don't know nearly as much about AC and the various units as I need to, or as much as Rod does at RO - I do know, though, that punching holes thru sound proofed walls doesn't work without long runs, baffling, and other ways of re-establishing the sound attenuation that was lost.
Check out the above thread and see if it gives you a better idea... Steve
Gee, I LOVE these last-minute bombs... First, what you suggested isn't a realistic approach, so we're still looking for the FIRST realistic approach...
Window style AC units have about the same sound attenuation as a double layer of Saran Wrap - putting louvers over one to direct sound toward the ground won't accomplish anything more than giving you something to build that doesn't work.
Unfortunately, from what I've seen there doesn't seem to be a practical way to use that type of AC unit in a studio, short of turning it up to 11, freezing the room, then shutting off the AC and plugging the hole with a MASSIVE plug and recording til it gets too warm, then repeating the process.
What you need is a split-type unit, and to add some multi-turn, large cross-sectioned ducts for both inlet and outlet, that are isolated from each other and absorbed at all turns in order to make up for the fact that you just put two holes in construction you worked very hard to make airtight.
Here is a thread that may help a little -
http://www.recording.org/ubb/ultimatebb.php?ubb=get_topic;f=34;t=000466
I don't know nearly as much about AC and the various units as I need to, or as much as Rod does at RO - I do know, though, that punching holes thru sound proofed walls doesn't work without long runs, baffling, and other ways of re-establishing the sound attenuation that was lost.
Check out the above thread and see if it gives you a better idea... Steve
knightfly
GrouchyOldFartOnBatteries
Jim, sound almost entirely doesn't care which direction it's going, if it can get out it can get in and vice versa. All you need is 2-3 bends and 12-15 feet of duct, with bends (at least) absorbed, for both the air INLET and the air OUTLET - that will kill enough of the sound so it won't be a problem either way... Steve
frederic
New member
A friend of mine mounted a window A/C in a basement window on the other side of the basement, then ran large flexible A/C ducting through the room the A/C was in, through the wall into his console room.
It definately worked, the console room was cool and reasonable. But, a little noisy. Nowhere near as noisy as having the air conditioner in the console room window, but it wasn't completely quiet.
Not my idea of ideal either. lol
Amped
New member
Just an update, the initial construction is finished and let me tellya, the floor in this thing is solid as a rock! With very little sound resonation to the outside and almost zero boominess. I guess the three layers of 3/4" OSB is doing its job. The electrics will be run this coming week, 100 amps with four dedicated circuits, the walls will follow, 1/2" exterior OSB siding with 3/4" OSB under the siding, quiet zone sound batting with a double layer of 5/8" sheetrock and a final layer of 3/4" asphault sheething to help treat the interior. The same for the ceiling. Im still researching the A/C dilema, but begining to form a plan. Im pretty stoked and cant wait to get this room working!
Thanks for all the help!
Jim
Thanks for all the help!
Jim
knightfly
GrouchyOldFartOnBatteries
First question: Are you still dealing with building inspection, or are they gone?
Exactly what (since it seems to change from post to post) do you already have for walls, starting from outside, layer by layer, to the inside? Include whether you went with staggered studs or two separate frames, etc.
I'll check back later today, don't mess it up this late by jumping the gun... Steve
Exactly what (since it seems to change from post to post) do you already have for walls, starting from outside, layer by layer, to the inside? Include whether you went with staggered studs or two separate frames, etc.
I'll check back later today, don't mess it up this late by jumping the gun... Steve
Amped
New member
Steve,
No more inspectors,
The walls from the outside in are as follows,,,,
!/2" osb siding,
3/4" osb,,
2x4 studs,,
quiet zone batting between the studs,,,
Single wall construction...,,
The buiding the way is is now, is extremely sound proof to the ouside, at 10' away, you cant hear but a faint sound from the inside, IE: wife yelling at the top of her lungs, stereo blasting at 10, stomping feet etc etc.
No staggered studs or seperate frames. Just a lot of mass. This is a quick response for right now, I need to get back to the grind.
Later.
No more inspectors,
The walls from the outside in are as follows,,,,
!/2" osb siding,
3/4" osb,,
2x4 studs,,
quiet zone batting between the studs,,,
Single wall construction...,,
The buiding the way is is now, is extremely sound proof to the ouside, at 10' away, you cant hear but a faint sound from the inside, IE: wife yelling at the top of her lungs, stereo blasting at 10, stomping feet etc etc.
No staggered studs or seperate frames. Just a lot of mass. This is a quick response for right now, I need to get back to the grind.
Later.
knightfly
GrouchyOldFartOnBatteries
Cool, Jim - what I would do now, is find a local source (probably a drywall/insulation contractor that does commercial) for Resilient Channel, and mount a layer of 5/8 and a layer of 1/2" drywall on that. No coincident seams, everything caulked with acoustic sealant, no drywall screws over studs, second layer of wallboard using longer Type S screws, NOT GLUED - leave 1/8" gap all around, and fill with acoustic sealant (same contractor may be able to help here) -
Have you done the ceiling yet? same basic plan will work there too... Steve
Have you done the ceiling yet? same basic plan will work there too... Steve
Amped
New member
Hey Steve,
I already have a case of USG acoustic sealant that Ive been using around the inside perimeter and around the door and any gaps I see in the framing. I checked into the RC and its available here localy so Im going to go that route, along with a layer of 5/8 then a layer of 1/2, caulking all seams with no coincident seams. (Type "S" screws???) I will use this same treatment for the ceiliing. When its all said and done, this should turn out to be a pretty quiet room, "fingers crossed"
Thanks!
Jim
I already have a case of USG acoustic sealant that Ive been using around the inside perimeter and around the door and any gaps I see in the framing. I checked into the RC and its available here localy so Im going to go that route, along with a layer of 5/8 then a layer of 1/2, caulking all seams with no coincident seams. (Type "S" screws???) I will use this same treatment for the ceiliing. When its all said and done, this should turn out to be a pretty quiet room, "fingers crossed"
Thanks!
Jim
knightfly
GrouchyOldFartOnBatteries
Jim, if you haven't already got it, go here
http://www.usg.com/Expert_Advice/const_handbook.asp?menu=
scroll to the bottom of the page, right click on the Construction manual download and "save as" to your drive - it's over 7 megs but a real time saver on answering questions about construction using drywall.
Your screw answer -
Type W (as in Wood)
Type S (as in Steel)
Type G (as in Gypsum)
The designator is what the screw fastens TO, not what it fastens. So for wood studs, a Type W screw is the one. For RC and Steel studs, the Type S screws are it. Type G is for laminating multiple layers of wallboard to each other, but should only be used if the wallboard is NOT on RC, and IS part of a sound wall.
For example, let's say you have a double framed wall between your control room and live room, and one side has the wallboard fastened directly onto the studs (since RC is supposed to be only used on one side, or it defeats the purpose) - Now, you want more than one layer of wallboard on the non-resilient side, in order to get a stiffer, higher mass wall for better bass isolation.
You can't just put screws through the first layer and into the studs when mounting the second layer, or the screws partially negate the first layer by flanking. So you need to mount the second layer without attaching it directly to the studs - this is where Type G screws come in. You spread joint compound over the first layer where the studs are, put the second layer up, and fasten it to the first layer OFFSET from the studs by about 2-3 inches and only fastened about every 12", this snugs up the second layer against the first layer, but DOESN'T completely laminate the two layers together (which would lower the coincidence "dip" and degrade the STC of the wall)
In your case, you'd use Type W screws to fasten the RC to the studs, overlapping the next piece of RC by 2-3" and using two screws at the overlaps - Mount the bottom row of RC with the long, open side DOWN, all the rest with the open side facing UP. Then fasten the first, 5/8" layer to the RC using Type S screws, making sure that you've marked where your studs are and NEVER put a screw through the wallboard where those studs are, only into the RC.
Then, you'd offset joints between sheets both vertically AND horizontally, and mount the second layer using longer Type S screws, again being careful to AVOID the studs; for each layer, leave 1/8" gaps all the way around the wall and caulk thoroughly before the next layer goes on. You should use 1/8" spacers under each piece of wallboard while fastening, then pull them and caulk before applying the second layer.
I think that's about it for now, I'll check every so often just in case you run into probs -
Be sure and download that Construction manual though - unless you've got broadband, it's a real PITA to wait for the pages you want and their search engine SUCKS - if you have it as a PDF on your drive, searching is quick and easy... Steve
http://www.usg.com/Expert_Advice/const_handbook.asp?menu=
scroll to the bottom of the page, right click on the Construction manual download and "save as" to your drive - it's over 7 megs but a real time saver on answering questions about construction using drywall.
Your screw answer -
Type W (as in Wood)
Type S (as in Steel)
Type G (as in Gypsum)
The designator is what the screw fastens TO, not what it fastens. So for wood studs, a Type W screw is the one. For RC and Steel studs, the Type S screws are it. Type G is for laminating multiple layers of wallboard to each other, but should only be used if the wallboard is NOT on RC, and IS part of a sound wall.
For example, let's say you have a double framed wall between your control room and live room, and one side has the wallboard fastened directly onto the studs (since RC is supposed to be only used on one side, or it defeats the purpose) - Now, you want more than one layer of wallboard on the non-resilient side, in order to get a stiffer, higher mass wall for better bass isolation.
You can't just put screws through the first layer and into the studs when mounting the second layer, or the screws partially negate the first layer by flanking. So you need to mount the second layer without attaching it directly to the studs - this is where Type G screws come in. You spread joint compound over the first layer where the studs are, put the second layer up, and fasten it to the first layer OFFSET from the studs by about 2-3 inches and only fastened about every 12", this snugs up the second layer against the first layer, but DOESN'T completely laminate the two layers together (which would lower the coincidence "dip" and degrade the STC of the wall)
In your case, you'd use Type W screws to fasten the RC to the studs, overlapping the next piece of RC by 2-3" and using two screws at the overlaps - Mount the bottom row of RC with the long, open side DOWN, all the rest with the open side facing UP. Then fasten the first, 5/8" layer to the RC using Type S screws, making sure that you've marked where your studs are and NEVER put a screw through the wallboard where those studs are, only into the RC.
Then, you'd offset joints between sheets both vertically AND horizontally, and mount the second layer using longer Type S screws, again being careful to AVOID the studs; for each layer, leave 1/8" gaps all the way around the wall and caulk thoroughly before the next layer goes on. You should use 1/8" spacers under each piece of wallboard while fastening, then pull them and caulk before applying the second layer.
I think that's about it for now, I'll check every so often just in case you run into probs -
Be sure and download that Construction manual though - unless you've got broadband, it's a real PITA to wait for the pages you want and their search engine SUCKS - if you have it as a PDF on your drive, searching is quick and easy... Steve
Amped
New member
RC will be here tomorrow, and installed. Now all I have to do is figure out a good way to bring the electrical outlet boxes out far enough to be flush with the inside wall. Ill probably nail a 2x4 between the studs at the correct distance and screw the boxes to the 2x4. The boxes need to be 2 1/8" beyond the framing.
knightfly
GrouchyOldFartOnBatteries
Jim, what brand of RC did you find? There are serious differences in performance...
For electrical, if you can stand it you'd be much better off NOT breaking the wall surface for boxes - even heavily caulked, they lose several dB of isolation for you. Better if you can use surface mount wiremold, and surface mount outlet boxes.
I've put the wiremold a couple feet off the floor, then used it to set acoustic treatments on - it pretty much disappears that way.
One thing I forgot to mention on RC - the first layer of wallboard should be put up vertical, it's closer to the way 99% of tests were done. Wallboard has a different stiffness horizontally than vertically. The second layer should be put up horizontal. To be doubly sure you don't "short out" the RC, be sure to use the right length screws for each layer AND mark the stud locations so you can STAY AWAY from them... Steve
For electrical, if you can stand it you'd be much better off NOT breaking the wall surface for boxes - even heavily caulked, they lose several dB of isolation for you. Better if you can use surface mount wiremold, and surface mount outlet boxes.
I've put the wiremold a couple feet off the floor, then used it to set acoustic treatments on - it pretty much disappears that way.
One thing I forgot to mention on RC - the first layer of wallboard should be put up vertical, it's closer to the way 99% of tests were done. Wallboard has a different stiffness horizontally than vertically. The second layer should be put up horizontal. To be doubly sure you don't "short out" the RC, be sure to use the right length screws for each layer AND mark the stud locations so you can STAY AWAY from them... Steve