FLOOR/CEILING/WALL CONSTRUCTION SEQUENCE

I've been doing this my entire life - and you do not caulk the perimiter of insulation - never been there -seen that - or done it....... For what possible purpose would someone reccomend that ? It makes no sense to caulk something which will freely pass water/vapor/air. I think either you missread something - or the site should be reported to the BBB....... Rod

"Are we getting closer yet?" YES! I'm not willing to go through the expense/hassle of trying to get up in the rafters to sheetrock...too much conduit up there, plus I would have to remove the existing runners, insulation, etc. **SO, how about a layer of GAF instead of a third layer of drywall? And where in the layering should that be applied? To the runners perhaps, and THEN the RC-1/sheetrock? (This is from Auralex' website regarding Sheetblok: "most effective when used as one component of a multi-layered construction scheme.") **The RC-1 will be mounted at 1ft. intervals for practicality AND strength. (The runners you see in pic #1 are spaced 1ft. apart.) **Would you recommend screwing the RC-1 through the runners and into the 2x4 joists that the runners are mounted to? It seems to make sense to me, but then again, what do I know? ***Which flooring is recommended, T&G OSB or plywood? "I've been doing this my entire life - and you do not caulk the perimiter of insulation" Good enough! That's all I needed to hear-just saved me time/money/headaches and I got plenty of all that going on! Steve, I want to thank you again for all the great responses/your time & commitment to this forum! I'm sure there will be subsequent questions as the construction continues. My main focus now is mounting the RC-1 properly (along the runners or across???)

Rod, thanks for helping out - my only thought on the caulk thing was that they were trying to "glue" the insulation in place - wierd, but you never know what people will come up with... LSB, if you have a name it would be great if you signed posts with it - I ain't gonna call you "Luv", wouldn't want Michael to get mad :twisted: Sorry I don't have any time to answer stuff tonite, we had a serious fire at work while I was off and now I'm getting stuck with extra 12-hour shifts, so tomorrow nite will probably be soonest I'll get a chance - The good news is, no body was hurt in the fire :D :D , even though it blew a 3000 gallon solvent tank across the road and will end up costing over $1million to get straightened out - Might get a few minutes in the morning, but don't hold your breath... Steve

Hi Steve...sorry 'bout the name thing. I used it on the first post of this page of our thread, but not in subsequent posts...my name is Dean. I guess I understand how you might feel uncomfortable calling ME Luv, even though the wall diagram you created for me (THANKX!) is called the Luvwall.jpg!! After all this is "over" I might have to send you a case of Shinerbock-sound good? I'm still looking for any repsonse about placement of the RC-1: ALONG the runners, or ACROSS the runners? Does it make any difference as long as I leave the 1/2" gap along wall perimeters? Am I sweating this stuff too much? I just put up one strip of RC-1 ALONG a runner and found it was quite easy to drive a screw through the RC where there is no screw hole. I did this to secure the RC-1 to the 2x4 joists that the runners are nailed to. ****Here is my only thought about the placement of the RC-1: As I will be using two layers of drywall plus one layer of GAF (the Sheetblok equivalent), I think it best to screw the RC-1 ALONG the runners, as they are spaced 1(one) foot apart, whereas, if I placed them ACROSS the runners, they would have to be spaced 16" apart in order to drive the mounting screws into the 2x4s. ****1ft. spacing=more stability for the RC-1 to handle additional weight of layers. DOES THIS MAKE SENSE TO YOU AS WELL? dean P.S. Sorry to hear about the fire at work-sounds like you have a dangerous job! That solvent is probably not very environmentally friendly either...

Hey Dean - you're right, I missed the one time you used your name - As far as the RC is concerned, normally it's run ACROSS the last framing members (the ones it's attached to) but if that will put the existing mounting holes out of range you'd be better to run it along the runners. I've seen a couple of comments from manufacturers that they do NOT recommend mounting this stuff other than the pre-made holes (except of course for the wallboard that's mounted TO the RC - that's a different story) USG recommends leaving a ONE INCH gap between the ends of RC and wall/ceiling intersections - and a 1/4" gap at intersections of wallboard itself, well-caulked. If for some reason you have to leave a wider gap, you can get foam "filler rod" to take up part of the difference, but I recommend sticking with the 1/4" if at all possible. "quite easy to drive a screw through the RC where there is no screw hole." - While this is true, it's not recommended. Not sure why, it's just not. 12" centers for the RC may be a bit close for only 2-1/2 layers :roll: of drywall - if you get the stuff TOO close together, you'll have too stiff a spring rate, and it won't do its job as well. If your runners are 12" apart, and laying FLAT, I'd think you would have no problem in finding coincidence between holes (real ones) and runners - As to placement, some people (including manufacturers) recommend putting the limp mass FIRST on the framing (whether studs or RC) and others recommend sandwiching it between wallboard layers. My take on this is that part of the reason for putting limp layer first is damping of the wallboard - you will have your fiberglas insulation to do that, and placing the limp mass BETWEEN the wallboard layers adds ONE MORE speed change for the sound, making it that much harder to get through. Even with 16" centers, you should be able to safely mount 3 layers of wallboard on RC - Of course, I would recommend getting this info direct from your SPECIFIC RC manufacturer - I heard that Dietrich recommends closer centers on their RC than some. That particular solvent isn't very environmentally friendly, but preliminary tests indicated that the containment measures worked as designed, and everything was either burned completely or contained. Now it's just ripping out all the burned, melted and ruined equipment and replacing it - gonna take a while... Steve

Hey-The holes on the RC don't line up either way I run them (across or along the runners). I guess I'm not really trusting the runners for stability, as the construction of the existing ceiling is old and the wood is dry and splits easliy if I screw too close to the edge (hence me placing screws where the 2x4 studs are, even if there are no pre-existing holes that line up with them). If I keep the screws a 1/2" to 3/4" IN from the edge than there is no problem with splitting. This still leaves me with a full 1" to 1 1/4" hanging out from the edge of the runner, so that there is no wood above where the drywall will be screwed in. [On that note, will the drywall screws go through the drywall AND penetrate the hanging RC without problems? It seems the RC section that hangs over is not sturdy enough to keep from bending up when trying to screw in the drywall (haven't yet tried, but...) Does the Drywall pressed up against the RC hold it in place enough that this isn't a consideration?] In order to keep the leaf from being too stiff due to RC mounted too close, what do you think about mounting RC on two adjacent runners (12" space), then SKIP a runner and then run two more, etc. Could this cause complications when putting up the second layer of drywall? [should the second layer be placed perpendicular to the first?] On second thought, maybe I WANT a stiff spring in the control room, 'cause I'm trying to keep footsteps from upstairs from being heard...I don't know...one thing my physics teacher way back in High School used to say over and over was "The more you know, the more you know you DON'T know!" I'm feeling more and more retarded as the days go on. :( Almost forgot--should ALL the pre-existing holes in the RC-1 be screwed? (I'm thinking, "Yes") I'll put the GAF inBETWEEN the layers of drywall! :D Thanks again Steve! dean

Man, you're up early for a Sunday - I'm on my way to the "DDJ" with little time, so I'll have to get this this evening, probably around 10pm your time, maybe a bit later - I'm not following how your RC can miss every stinking hole, can you post a pic of the stuff, laid next to a ruler or yardstick? Old wood - it's a bitch. I'd get some adjustable depth screw pilot bits and sink some 3=1/2" #12 screws thru the flat runners into the joists - you MUST pre-drill and countersink, or else take the old stuff down and start over :cry: Shoot a pic or two, maybe a rough drawing of exactly what you're trying to put where, you're losing me here... Steve

Sorry for the confusing post...what I meant to say was this: because the wood is old, I want to screw the RC through the runners and into the 2x4 studs. Placing the RC across or along the runners makes no difference, the holes don't line up with the 2x4s. I'm outta time right now-get back to you tomorrow.

"I'm outta time right now-get back to you tomorrow" - Right back atcha - still don't understand what type RC you're using that doesnt have holes on 12,16,and 24" centers. If you could shoot a pic that shows about 2 feet of your RC alongside a clearly marked ruler or yardstick? Thanks... Steve

"...doesnt have holes on 12,16,and 24" centers. If you could shoot a pic that shows about 2 feet of your RC alongside a clearly marked ruler or yardstick?"

I'll try to get the camera again. In the meantime, the RC's holes are spaced 5 3/4" apart.

you MUST pre-drill and countersink, or else take the old stuff down and start over

Good enough. I will pre-drill...Do you still think that a stiff leaf on the ceiling of the control room (due to narrow spacing of the runners) is going to be an issue? I am only trying to knock down the sound of footsteps from upstairs.

Your RC will ease the stiffness, but not if it's too close together - that's a really odd hole spacing, you're right it wouldn't line up with anything NORMAL. Looks like you may have no choice but to put the screws through wherever your runners are. IF so, then we need to find out the recommended spacing/layer count - Do you have a manufacturer and or part # of your RC? Steve

Do you have a manufacturer and or part # of your RC?

I'll get this information from the supplier today (Wed.). When I spoke with one of the salesmen about using it for the ceiling, he said that his "guys" put one layer of drywall up first and then the RC through the 1st layer of drywall and another layer on the RC. I said my application is different...anyway, I'll get back to you on the part#, etc...I wanna take a pic of this stuff so you can see it. dean

Steve, It's Dietrich RC-1 (formerly Unimast)...I've been told that I don't need to use every hole, AND I don't need to use ANY of the holes as long as I'm driving a screw through the furring strips (what I've been calling runners) into the 2x4 joists. In fact they have recommended (for sound isolation) driving screws ONLY where the RC crosses the joists and no screws in between. You recommended 3-1/2" #12 screws in an earlier post...is this still the case (with a pre-drill)...been using 2-1/2"...I've only mounted three pieces, so I can easily fix those. dean

Dietrich doesn't recommend their URC product for ceilings, only the RC Deluxe and the RC-2 (not my choice, less isolation with two legs) - can you pick yours out of these, or is it different yet? http://www.dietrichindustries.com/bigdp ... sories.htm On screw length/type, you want wood types for fastening the RC to the runners (furring strips), and to be safe you either need to use pilot holes and screws to fasten the furring strips better, or put screws clear thru the RC, furring strip, and at least 1" into the joist. If it were me, I'd do these operations separately - fasten the furring strips better with long screws, then use normal length (1-1/2" for ceilings) to fasten the RC to the furring strips. This will keep the extra tension of the furring strip screws from pulling through the thin RC metal. In every case, I'd drill a pilot hole that clears the body(minus the threads) of the fastener, or you'll have splitting problems with that old dry wood. For mounting the wallboard to the RC, you need screws for STEEL - they need to be long enough to pass thru the RC by at least 3/8", in order to make sure they get good thread contact with the RC. Subsequent layers will of course need longer screws. Don't put ANY screws thru the wallboard where the furring strips are - you can use masking tape around the perimeter to mark these locations, then snap a chalk line ELSEWHERE for your fastener locations. Make marks that line up with those chalk lines also, so you can put your second layer's screws ELSEWHERE and avoid collisions. But first, make sure WHICH RC you really have, and if necessary contact Dietrich directly for advice - each manufacturer has their own set of rules, and usually good reasons for them. It amazes me just how FEW builders understand sound control though - (don't EVER put RC between wallboard layers unless there's no wallboard at ALL on the other side of the studs) you'd think that the isolation requirements for new construction would spawn at least a FEW education attempts... Steve

can you pick yours out of these

DIETRICH URC™ Resilient Channel-not recommended for ceiling. I'm going to have to look around to find something better, as most places only carry the above...

you'd think that the isolation requirements for new construction would spawn at least a FEW education attempts...

We're a lazy race, no? :cry: I'm getting an education, though! Thanks for the clear points on mounting the RC and wallboard! One other question...the second layer of wallboard should be put up...how? Offset by the first layer by a few inches? I've read the posts for WALLS, but is the ceiling a different beast?

Yeah, its number has been estimated at 666 :twisted: The EDGES of the ceiling should go as I drew them, http://www.johnlsayers.com/phpBB2/viewt ... c&start=45 with BOTH wall layers (or ALL of them) going ALMOST to the ceiling joists, but NOT touching them - then, BOTH or ALL ceiling layers stop leaving 1/4" gap to the wall layers, which extend ABOVE all the ceiling layers. (The RC takes care of this) Then, use acoustic caulking and seal all the gaps well. The individual layers of wallboard, however, should NEVER coincide their mid-field seams in EITHER direction but be offset by at least a foot, preferably by one joist (either 16" or 24", whichever centers are used) This means that for a second layer (assuming 24" centers and 48" wide sheets) you would start with a HALF-width sheet, placed at 90 degrees from the previous layer and offset lengthwise by one joist - then, subsequent joints will fall in the middle of previous layers' panels instead of being coincident. This is definitely different than intersecting walls (other than the seam offsets, which should be done same as ceilings), which should alternate layers, being caulked as you go, so that the finish joint has a caulked, Z-shaped pattern for best isolation. Even the wall/wall intersections should be gapped and caulked so there is no hard contact between intersecting walls though. By "wall intersection", I do NOT mean the continuation of a straight wall, but a place where two walls meet at an angle OTHER than 180 degrees... The reason for ceilings being done differently is so that the ceiling wallboard can "float" inside the walls without settling and forming a hard contact between wallboard and ceiling panels. The acoustic caulk is flexible enough not to crack with quite a bit of settling, and should maintain seal. However, if the wall/ceiling joint were "Z'd" same as wall/wall joints, settling could squeeze out enough caulk to form a hard contact and deteriorate the isolation between surfaces. That would reduce the isolation overall, partly because of one surface exciting the other un-necessarily. Glad you're learning a lot - given enough beating of our heads on walls, this stuff finally starts to make sense (right about the time we need "rubber rooms" for something besides acoustic reasons :roll: ) Hope you can find the RC Deluxe somewhere - besides the extra strength, it gives you a wider "target" to hit with your screw gun... Steve

I ordered the RC Deluxe and it should be in next week. I spoke directly with a Dietrich Industries regional sales rep. He was quite helpful. He even took the time to look at the pix I had posted on pg. 1 of this thread and gave me some feedback about mounting the RC (ACROSS the runners and along the joists). Steve, do you snap a chalk line across the wallboard to know where the RC is? I'm going to rent a panel lift to do the ceilings. First I need to finish the flooring, though. Do you recommend 3/4" on top of 1/2" (or vice-versa?)??? Can I put down 3/4", GAF and then the final flooring? The more I read the posts, the more conflicting info I get (kind of like some manufacturers recommend mounting the RC ALONG the runners on the ceiling and others just the opposite). I now have the sequence of construction pretty much in my head through all the posts-thanks a boatload, Steve! One more question, though...windows. Should I have the windows in before the wallboard goes up? Or should I get the walls in place with the cutouts for windows and THEN install them? Does it matter? dean

Flooring - I'd do the Gaf sandwich thing - are you floating this, or?? Windows - which windows, the one between iso and CR, or outside windows? What did the Dietrich guy say about spacing of their RC for ceilings vs. # of layers? I've heard different versions and have not had time to conflab with them at all. chalk lines - yes, definitely. before you put up the first layer, put masking tape strips on the walls, around the ceiling perimeter (or just mark on the wallboard) exactly where every framing member is on the ceiling (at least the furring strips and RC) then you can snap new chalk lines for each layer. If you snap a chalk line where the RC centerline is, then snap lines at right angles to that in increments of 12" (if that's to be your fastener spacing) - mark those on the wall (and label them) so you know where NOT to put screws for the NEXT layer. The second layer fasteners should be offset by 4", being careful NOT to allow fasteners over the furring strips. This requires planning ahead, and in the case of 3-layer ceilings you'd need to vary spacing to something other than even increments of 4" offset per layer, in order to MISS your furring strips completely on either side. If all that's too confusing, yell and I'll do a basic drawing showing screw spacing layer to layer... Steve

Flooring - I'd do the Gaf sandwich thing - are you floating this, or??

Yes, I'm floating the iso room for sure-already framed and on top of the neoprene pads! And yes, I was planning on doing the GAF sandwich thing, but between WHAT? Two 3/4" layers? One 3/4" and one 1/2"? Or 3/8"? I've read in several threads of people using one layer of 3/4" others used 1 1/4" OSB or something like that, so I'm undecided.

Windows - which windows, the one between iso and CR, or outside windows?

Yes the window between the iso and control room...and well, the one between the iso and main room, too, for that matter.

What did the Dietrich guy say about spacing of their RC for ceilings vs. # of layers?

Basically he said that using the 16" OC joists for my situation is fine, especially with two layers of 5/8" and one 1/8" GAF--definitely not the 12" spacing I would have used had I placed the RC ALONG the runners. I think he said that 20-24" is for a "normal" application.

If all that's too confusing, yell and I'll do a basic drawing showing screw spacing layer to layer

It only took two readings to get that! But, if you draw a picture my comprehension will increase tremendously. The various pictures and drawings on this forum (and others) have helped a great deal. Those pix/drawings combined with your text is a really good book waiting to happen! The Layman's Handbook on Studio Construction, by Steve Knightfly. (I'dda bought it!) I've skimmed the other books...too much info for someone like myself who doesn't have the burning desire to know WHY this method/material works, but just wants to know HOW to get er done! I'd rather read the manual for my Distressors and try to get a different effect out of 'em!! :D More importantly I've begun reading the manual for my RADAR 24 and can't wait to finish construction so I can unpack that baby! :D :D :D Steve, as always, I really appreciate all your great help here!:mrgreen: :mrgreen: dean

On most RC, 24" centers will support two layers of 5/8 sheet rock, so that sounds normal. I'd tighten it up since you're adding the triply, probably to 16" (just in case your ceilings don't cut sound enough to upstairs, you'll have the option of a third layer, preferably 1/2" if you have two 5'8" layers already up) floor - are your 2x4's laid flat or on edge, and how far apart? That's one of the things more people forget to mention when describing things, is which way things are oriented and how far apart... Hopefully I'll get a chance to work on a drawing tonite or tomorrow nite, it'll probably end up as a PDF file so if you don't already have Adobe Acrobat reader you should hit their site (adobe.com) and download the free reader (they don't show up on this site otherwise) Running late for work, so I'll catch you later... Steve

Dean, it's gonna take a few days - water's rising in the swamp again, damn alligators are gettin' too close to personal stuff again... Steve

(just in case your ceilings don't cut sound enough to upstairs, you'll have the option of a third layer, preferably 1/2" if you have two 5'8" layers already up)

Right on!

floor - are your 2x4's laid flat or on edge, and how far apart?

Oops! Sorry 'bout that. FLOORING= 2X4 on EDGE, 16 OC with cross pieces between the joists every 48" (this was done for a little more support and for the Thermafiber to fit into). I see SAE recommends 2 layers of 3/4". I'm thinking I should float the control room as well, in order to knock down any flanking noise from the wall that I had already built (the one in the pix). pdf. files are not a problem. Windows: best steps for construction most appreciated! dean P.S. SURE GLAD THE SERVERS ARE WORKING AGAIN!

Hey Dean, it's been a while since the site's been up, and I've been 'way too friendly with the 'gators to have accomplished much either. How 'bout an update, so we can cover whatever points you still need help with? Steve

Hi there Steve, Glad the site is back up...UPDATE: I've completed the floating floors in iso and control room as well as the floated wall in the iso as per your directions-THANKS! It worked, but was a little tricky getting that wall up (the luvwall.jpg if you recall). Just for clarification, my floors consist of: 2X4 framing on neoprene pads, filled with Thermafiber, then 1/2" plywood, GAF 1/8" rubber/vinyl, and 3/4" on top. The final finished floor remains up in the air... My next dilemma...well, I'll have to take a picture to explain it...check back in a few days... Windows and doors are the next challenge to prepare for. I've downloaded diagrams/pix etc., but none show the actual construction materials/process. I have some heavy duty solid-core doors, but no framing for them. I was told to add 2" to the width for the 2X4 framing so that the door jams(?) can be attached to the framing, leaving enough room for a 36" wide door. I've not seen any clear directions for this process and can only imagine how that would work. Even the studio door manufacturer sites only have diagrams limited in scope (mainly focused on their products, no surpise there). I guess there is a basic assumption of how doors are built...I just want to build a door using the ones I have with a door frame that will seal well enough to cut down on sound transmission. I'm not looking for world class results, just functionality with decent isolation. The Acoustical Solutions website shows a few things...the threshold-should it be screwed to my subfloor, the finish flooring or another piece of framing? It seems there are several solutions for good doors. I don't want to spend $1000 or even $500 on my doors. Any suggestions? For window jams, is there a recommended width/thickness? How about window size (overall)? I'm at a point where it would not be too much hassle to decrease the size of the windows (currently, and without any jams/sills, the dimensions are 42 3/4" H X 32 1/2" W). I'll try to get some pix of my other problem posted later today (1/12). Glad you're back online! :D dean

See if this helps any on the fundamentals of door hanging - http://www.easy2diy.com/cm/easy/diy_ht_ ... d=35694582 Keep in mind that for sound construction, the little shims that most carpenters use to align door frames to rough openings aren't good. You need to thoroughly caulk both sides of the frame after installing the jamb, between the jamb and the wallboard. Also, if using multiple sheets of wallboard, the jamb needs to be wider to cover both layers of wallboard. Windows and doors both - here's one good link for a general idea of what's required - http://www.saecollege.de/reference_mate ... indows.htm - the smaller the window, the less the sound loss (windows are harder to soundproof than walls) however, it also means less communication ability. Extra space between inner and outer glass, thicker glass, no hard contact between inner and outer frames, all help improve Transmission Loss. Look over the drawings and come back with your un-answered questions on them, and I'll see if I can clear things up a bit... Steve