This post is similar to:
"Existing wall is already MASS/Air/MASS so the new wall....?" by apexer
But my building, of course is different, and your feedback is GREATLY appreciated.
Location: Minneapolis, MN. Recently aquired (may 05') 2 story (zoned non-conforming use) storefront building on residential block. Main floor: Commercial space. 2nd floor: Apartment of building owner and studio partner (*not an isolation concern)
Basement: unfinished.
Building sits 10ft. from street on front entrance, 18ft from side (local traffic @ 1 car every five minutes) and street is used by local fire emergency vehicles :cry:
Neighbors: Building is on corner lot across the street from a park, neighbor to the right is 28 ft. away, neighbor to the behind is ~50ft.
Size: The open mainfloor exists now within close proximity of 650 sq. feet (obviously not ideal). 9'5" cielings.
Existing Build:
FLOORS- subfloor (planks, 5/8 ply), 5/8 sheetrock, green glue, 5/8 plywood.
WALLS- Stucko, tar paper, plywood, 2x4 frame, lathe and 5/8"plaster, and newly added 5/8 sheetrock. (now i've learned that I would have been better off removing the plaster and beefing up the outer leaf,... right?) New windows... we were told by the city that we cannot remove any windows because there is a wall/window percentage requirement for sides facing the street on commercial buildings! :? SO, we can't remove the windows, but can wall them in from behind! go figure... So, we're HOPING to be able to utilize the light instead of walling them all off. Call us stupid... and you're probably right.
CIELING- 5/8" plaster and a 17'x13' section of 5/8" sheetrock above CR... and it's hard to tell what is above that, but it looks like a layer of wooden planks, plywood, and then hardwood tongue/groove. The walls upstairs are all plaster, old insulation (the pink stuff), ply, stucko. Lots of windows upstairs!
Budget and time constraints: No time constraint. Our budget as of now allows for a max of 15,000 (construction, separate budget for equipment), including all contracted work (elect, hvac). We've already blown through almost 4,000 just fixing structural issues like a water damaged exterior wall, and demolishing everything that was in the room before (kitchen, bathroom, giant cabinets, etc.) and building our floor and adding refinishing the walls. Minus 4,000 for a Mitsubishi Slim AC system, and an estimated 3,000 electrical/alarm installation, we're looking at 4,000 left. I jumped the gun and purchased all 2x's and a roll of neoprene (durometer 60), so what's left to buy is rock (walls, cieling), caulk, DOORS, and treatment material. So, we may need to scrounge up some more money because the doors alone may kick our a$$.
Intention: We hope to record anything from quiet jazz to loud rock w/ amps, drums, etc., so a high STC and LF TL is desired. One thing I'm just realizing now is that I haven't yet tested to see what the current db level of drums, etc. at the property line, the way the building stands. I suppose I should do that, but really, we want to shoot for the most isolation possible.
Plans: Below is a pic of our current floor plan idea. All of the inside walls are what is left to build. Our original idea was to construct our walls on a 2x6 base, stagger our studs, hang the new cieling on the walls, thus winding up with a 2 leaf wall inside of a two leaf wall with a minimal gap in between. HOWEVER, I have recently learned that this is most definitely not a good idea. The wall dividing the CR from the PR will be a double wall construction (layers of rock, RC, 2x4 frame, insulation/air,separate 2x4 frame, RC, layers of rock.
QUESTIONS: (let me know if they don't make sense to you)
1. Since we have finished the existing interior leaf so that it is now plaster and 5/8" rock: Would it be most effective for a high STC rating and LF TL to build a new single 2x4 frame (possibly on proper amount and density of neoprene), insulated, ~2-3" from the existing interior leaf with 3 layers of varying thickness gypsum hung on resilient channel on only the side facing the interior room? Would it help to add another layer of gypsum to the existing interior leaf?
2. Is it even possible to achieve high enough STC ratings/LF TL if we attempt to keep the windows and build new (glass block) windows in the new wall? I understand that these and my doors are going to be my weakest points. Would it help to seal in the existing windows with another pane of plexiglass before I build my new walls?
3. I'm planning on building the cieling with 2x4 joists (to save hieght) resting on top of the wall cap and hanging 2 layers of rock on hat channel. I'll insulate the spaces inbetween the joists and call it good... unless someone thinks this isn't kosher. Would it help to rest the cieling on neoprene pucks and seal the gaps? I'm sorry, I don't have a drawing for the cieling! :oops:
4. Is this shit even worth it?... or should I throw my hands in the air and say screw the music industry, I'm building a big living room!.... HA HA HA! :) :) :)
O.K. I hope I didn't exclude any details. THANKS TO ANYONE WHO CAN OFFER SOME ADVICE.
Wall details, airspace, clarification please!
Originally posted at johnlsayers.com, topic 6012.
I hate to be the one to tell you this - but your real question should be: "So what's the first thing I should do after throwing away all that money working on the interior face of the existing exterior wall" I cannot for the life of me figure out why so many people throw money away and THEN come here to ask questions? It seems to me that anyone trying to build something (especially people with budget constraints) would want to make certain that every penny they spent was well worth the investment. The answer here is the same as it is in the other thread....... First - pull off the drywall and plaster from the existing exterior walls - throw it all away (you might be able to save a few pieces of the drywall if you're real careful) and then you're ready to start work on the space. By the way - you said that you have already built your floor - exactly how did you build it?1. Since we have finished the existing interior leaf so that it is now plaster and 5/8" rock: Would it be most effective for a high STC rating and LF TL to build a new single 2x4 frame (possibly on proper amount and density of neoprene), insulated, ~2-3" from the existing interior leaf with 3 layers of varying thickness gypsum hung on resilient channel on only the side facing the interior room? Would it help to add another layer of gypsum to the existing interior leaf?
Search the archives here - there have been a number of threads concerning effectively closing in windows - with details provided.2. Is it even possible to achieve high enough STC ratings/LF TL if we attempt to keep the windows and build new (glass block) windows in the new wall? I understand that these and my doors are going to be my weakest points. Would it help to seal in the existing windows with another pane of plexiglass before I build my new walls?
What makes you think you need hat channel? I don't see 2x4 ceiling joists carrying the load alone - you'll have to provide some intermediate supports (isolated of course) to carry the load with those members. You will also have issues with the existing ceilings....... the drywall(plaster?) should dissapear.......... Rod3. I'm planning on building the cieling with 2x4 joists (to save hieght) resting on top of the wall cap and hanging 2 layers of rock on hat channel. I'll insulate the spaces inbetween the joists and call it good... unless someone thinks this isn't kosher. Would it help to rest the cieling on neoprene pucks and seal the gaps? I'm sorry, I don't have a drawing for the cieling! :oops:
Rod, since they covered plaster and lath with an extra layer of 5/8" drywall, might it make some sense for them to live with the effects of the third leaf and attempt to compensate for that shortfall by adding even more mass to those walls from the inside (i.e., adding another 5/8" layer, perhaps using a Green Glue sandwich) and then building new inner frames with lot of mass and a generous air gap?
Well, now you're assuming everyone that's building a studio for the first time knows about the "johnlsayers.com" forums. We didn't walk into the construction completely blind. We had a veteran engineer who teaches at McNally and Smith College of Music and Recording Technology consult us and we trusted his word. Not everyone is aware of the best methods of building in a less than ideal space like ours. But anyway... there's no point in talking about what's been done. FLOORS: after it was stripped of pre-existing materials, we leveled the floor with plywood and mud, added a layer of 5/8" sheetrock, green glue, and a layer of 5/8" plywood to complete the sandwich. CEILING: I assumed that hat channel would be beneficial. I'm searching for answers, not questions. ThanksI cannot for the life of me figure out why so many people throw money away and THEN come here to ask questions? It seems to me that anyone trying to build something (especially people with budget constraints) would want to make certain that every penny they spent was well worth the investment.
Actually, this forum (and others) are good for searching for answers, as well as searching for questions that you should be asking of yourself. 8)
I do sympathize with your situation... You consult someone whom you think is an expert, only to realize after it's too late that the advice given was not sound (no pun intended). :roll: That's the trouble with this science... Few people really understand it, yet there's no shortage of people who think that they do or don't think there really is much to understand. :evil:
It took me eight months of serious planning and research before I pulled my construction permit for my project. This forum was invaluable to me during that process.
Please do yourself a favor... Slow down (meaning stop building) and spend a few weeks here learning (and unlearning) all that you can. You will be glad that you did. 8)
--Keith :mrgreen:
I can relate to your situation. That is taking advice or just talking about a sound isolation studio build, with a so called “professional”. :roll: but I've not started my studio room yet.
The architect I used to draw the design for the addition to my house which my studio will go in was absolutely clueless to sound isolation. I had to argue with him about details on my outer walls (leaf). My inner wall (leaf) is not even in the design. There are lot’s of building professional’s out there who don’t know. I’ll try and quote Rod from his book “it’s not there fault, they just don’t deal with it often if at all.”
BTW Rod is the guy who wrote the 1st reply to this thread. After reading Rods book Rod's New Book - (You NEED this) , many of his posts on this forum and on his forum: recording.org IF Rod or Steve (Knightfly, MOD of this forum) were to say “jump of a bridge, Marc” (in regards to building my studio) I would read it again, make sure I understood the procedure, check for plumb and then jump.
Hat Channel verses RC (Resilient Channnel)
Please see pic on 1/2 way down this page:
http://www.ta-inc.com/newshtml/rc.htm
AND a quote from that page:
Hat Channel has no holes in it, RC does which creates decoupling of wall board (drywall) from structure. There are more ways to decouple RC further (when done correctly). The only very, very, very small benifit Hat Channel may have is adding some air between the two mass's. :cry: I can't comment to much on your floor. I'm curious if green glue was worth it in the floor, I've not seen that done or suggested. 8) Like Sharward said, maybe you want to stop building for a while and spend some time studying and reading these great forums. The only faster way around gaining the knowledge may be to buy Rod's book. :D or another like it. MarcIt is important to distinguish acoustically effective resilient channels from hat channels, z-channels, and other lightweight metal furring systems. These other systems may resemble resilient channels, but they afford no movement and are simply too rigid to be effective. Only resilient channels have any acoustical benefit.
:lol: :lol: :lol: :lol: :lol: :lol: :lol: Classic! :lol: :lol: :lol: :lol: :lol: :lol: :lol:IF Rod or Steve (Knightfly, MOD of this forum) were to say “jump of a bridge, Marc” (in regards to building my studio) I would read it again, make sure I understood the procedure, check for plumb and then jump.
I don't think there is any other like it!! 8) --Keith :mrgreen:. . . buy Rod's book. :D or another like it.
Yeah, I've not seen one either. MarcI don't think there is any other like it!!
Win, I apologize for coming off gruff.......... it's just very frustrating when you have to begin a conversation by saying - "OK - first tear off everything you've already done."Well, now you're assuming everyone that's building a studio for the first time knows about the "johnlsayers.com" forums.
That's something else that really rubs me the wrong way - the fact that someone is an expert in recording does not mean they have a clue about acoustics - and instead of their making beieve they do - and costing someone hard earned money - they should just honestly say "Listen - it's not my area of expertise - you should hire an acoustic engineer so you can get iit right".We didn't walk into the construction completely blind. We had a veteran engineer who teaches at McNally and Smith College of Music and Recording Technology consult us and we trusted his word. Not everyone is aware of the best methods of building in a less than ideal space like ours. But anyway... there's no point in talking about what's been done.
I have no idea what the long term effect of gravity and live (moving) loads will have on green glue - my best guess would be that it's value will be short lived due to thinning out over time - however I will make it a point to ask Brian Ravnaas and get back to you with the answer.FLOORS: after it was stripped of pre-existing materials, we leveled the floor with plywood and mud, added a layer of 5/8" sheetrock, green glue, and a layer of 5/8" plywood to complete the sandwich.
Hat channel has no benefit - as already pointed out to you - and you really need to (as also pointed out to you) begin searching for the questions you don't know about yet - because other wise you will continue to throw money away. My best guess right now is that (unfortunately) you can't get from A to B without removing work already in place. You start with a task that's daunting to say the least - and begin with taking the worst possible step you could - with the creation of the 3 leaf wall system - and that with an outside leaf that has little mass and little isolation value. SO if you build a wall within - and add a layer of 5/8" drywall to it - you'll have (with the plaster) maybe an STC rating of 51......... remove the drywall and plaster and it will grow to about 57 - take the drywall in between the walls and move it to the inner-most face and it will become 60 - add a layer to the outside face and it will become around 60....... add another layer to the outside face and it will grow to around 63 - so a weighted average isolation of 63dB with the exterior sheathing - + 2 layers of exterior drywall + 2 layers of interior drywall. 5 layers total. Beyond that - you would add double the mass to the interior to gain another 5dB of isolation. 2nd scenerio - add the innner wall (leave the outside exactly like it is now) - add 2 layers of drywall to the inside face and you will have around an STC 54 - to gain 5 more dB in reduction you have to double the mass - so that means another 5 layers to the inside face buys you up to STC 59 - and then it would take another doubling (add 10 more layers) to reach 64. All this because of the center layer (the third leaf) so STC 63 = 5 layers - or STC 64 = 20 layers. You do the math. Now - This all assumes that flanking doesn't take over - and your deck - although decent from a construction point of view - is not isolatted - so it's a direct planking path to the outside world. Isolating the ceiling framing from the existing structure will help of course - but when everything is said and done - your entire assembly is only asd good as it's weakest point. I hope this helps you to understand what you're up against. Sincerely, RodCEILING: I assumed that hat channel would be beneficial. I'm searching for answers, not questions.
Amen to that!! This is true of so many things in life.That's something else that really rubs me the wrong way - the fact that someone is an expert in recording does not mean they have a clue about acoustics - and instead of their making beieve they do - and costing someone hard earned money - they should just honestly say "Listen - it's not my area of expertise - you should hire an acoustic engineer so you can get iit right".We didn't walk into the construction completely blind. We had a veteran engineer who teaches at McNally and Smith College of Music and Recording Technology consult us and we trusted his word. Not everyone is aware of the best methods of building in a less than ideal space like ours. But anyway... there's no point in talking about what's been done.
AMEN!! Well Rod, and others, thanks a LOT for your help! I'll be sending a link off to the engineer that consulted us and spread the knowledge in Minneapolis and St. Paul. -LanceWe didn't walk into the construction completely blind. We had a veteran engineer who teaches at McNally and Smith College of Music and Recording Technology consult us and we trusted his word. Not everyone is aware of the best methods of building in a less than ideal space like ours. But anyway... there's no point in talking about what's been done. That's something else that really rubs me the wrong way - the fact that someone is an expert in recording does not mean they have a clue about acoustics - and instead of their making beieve they do - and costing someone hard earned money - they should just honestly say "Listen - it's not my area of expertise - you should hire an acoustic engineer so you can get iit right".