16"OC vs. 24"OC/ Vapor Barrier vs. Vapor Retard

"Ladies and Gent's! Tonight's card features the LOW frequency performer 24"OC vs the Standard brute 16" OCeeeeeeeeeeeee!!! (Aw man, I JUST couldn't help but dothat!!) :lol: :wink: :? :shock: :roll: Uh, ok...down to Biz... :? It seems as though building a 24" OC frame will give you better performance in the lower frequency range than a 16" OC frame. At present, my "outer" walls are 16 OC. I was thinking about putting my inner walls at 24" OC but I'm not sure what effect it would have seeing that the frames are different. Would it help by putting my inner frames at 24" OC, or should I stick with 16? Also this question... Is there a difference in using insulation with a paper vapor barrier as opposed to laying a sheet of plastic across a frame as a vapor barrier? Thanx!

Not much time right now, but you need to learn the difference between a vapor barrier and a vapor retarder. Most people say barrier when they mean retarder. You most likely want a retarder. Kraft paper is a retarder. Plastic sheeting is a barrier. And be sure it doesn't "split your air gap," in which case you'd end up severely compromising the benefit of your air gap (third leaf effect). On the stud spacing, in general, "floppier" is better for noise control, so go for 24" if you can do so legally. Verify with your local building department. --Keith :mrgreen:

Thanks for the reply Keith! I checked out the difference. That helps a lot! (Before I begin this post If one of the "experts" can answer the question in my last post, on the link below, I would SINCERLY appreciate it!! I'm in the process of ordering materials, and I don't know which type of Butyl sheeting to get...Here's the link... http://www.johnlsayers.com/phpBB2/viewt ... c&start=15 Ok, in the 1st pic below, I guess what I now have would be a vapor "barrier". When they built this house all they put in was the plastic "barrier" over the insulation. (Maybe an inexpensive way to have some type of vapor protection by the home builder or possibly a temporary fix?) The insulation has no paper on it. The frame in this pic is the "walk-out" frame on the back of my home in the basement. (ALL of the other walls are concrete slab) I guess my concerns fall under the "general home construction" area which I have little knowledge of. I'm not sure if all I need is vapor "retarder" insulation or a vapor barrier. According to this topic and a post by Steve about 3/4 of the way down, you don't need both. http://www.johnlsayers.com/phpBB2/viewt ... c&start=75 I guess I'll be on the phone tomorrow getting info on this along with the, er' Planning Commission again...(Remember in another post where I said the secretary, the inspectors and I will know each other on first name basis???) I'll call them and ask about the 24" OC framing. In the second & third picture below (which by the way is a modified drawing from another post that had a basement similar to mine) I tried to keep my M-A-M setup consistant by adding 3 sheets of 5/8" drywall to the other layers on the outer leaf of my house. Unless I have this wrong, the outer layers of materials along with the 3 sheets of drywall running right behind them will form my first "mass" leaf because there is no air space between any of the layers. The insulation and 1" air gap will form the "Air" part of my M-A-M system; then finally the 2 sheets of 5'8" drywall on the 2x4 frame will form my other leaf of "mass". The thing is, because the insulation is right next to my slab wall or on the "walk out" frame on the back of my house, I will need to have the paper faced "retardent" insulation or the plastic "barrier" sheet. If it's the paper faced insulation OR the plastic sheet barrier, I see no way I can avoid a 3-leaf system. If the paper on the insulation or the vapor "barrier" is right behind my drywall, (as in the drawing in pic #3) then there will be some areas where the paper will not be flush against the drywall thus creating an "air" gap which=a 3 leaf system. Maybe because the paper or plastic sheet would be flush on the drywall in some areas won't make it a "devistating" thing. Heck, I'm not sure, plain and simple... :|

May I suggest changing the subject line of your original post in this thread to... Studs: 16" o.c. vs. 24" o.c.; Vapor Barrier vs. Vapor Retarder ...since you're discussing both. That should get the attention of some of the experts around here who are well versed in either or both of those items. Yoo-hooooo! Rod? :twisted: Steve? 8) --Keith :mrgreen:

GREAT idea Keith...That's a done deal. Also, I Googled Paper Insulation and got an explaination of a Vapor Retarder and Vapor Barrier. Think I know a little better now...Thanx man... UPDATE: I called the planning Commission today and was told I could do the 24" oc framing. Hey, the Inspector even remembered me and the area I live in. He gave me his name and even told me no matter what questions I had to call him and he would answer them. He even said I could write down any questions and leave them on his desk and he would get back to me OR he would come out to the house if I needed him to! WOW! That's a BLESSING...Seems like he's willing to "work with me" on this thing...(Hmmmm...maybe he's a musician??? :wink: )

That's wonderful to hear, camistan. :-) Experiences like yours dealing with "the horrible, terrible, mean, egostical bastards that are the building department" that turn out to be "approachable, professional, able and willing to help you building department" help to break down barriers. So often people are afraid to ask for fear that they'll be told that can't pursue their dreams. Often the result is quite the contrary -- that these folks can actually help one fulfill their dreams if one lets them. 8) I'll bet those building department folks actually find citizens like you to be a breath of fresh air. I really think they strongly prefer to help people do stuff right than to tell people what they've done wrong after the fact. --Keith :mrgreen:

bump

Stan, on the floor thing - I think you're over-thinking and over-spending to buy separate butyl sheeting - in your case (MIDI studio, non-metal volume levels) it's not necessary or even desirable (cost-wise) - instead, I would go for one of the commercially available "floated" floor systems that include a soft sheeting layer, and follow their directions EXACTLY (along with taking pix during install) That way, if there's ever a problem you'll have a better chance of warranty doing some good - I would NOT support your inner stud frames on this, but simply use 2 layers of 30# roofing felt under the frame plates. See attached crude drawing. Your ceiling should be resiliently floated INSIDE these walls and caulked using backer rod and caulk (see reference section under caulk, there are about 3 threads) According to this http://www.buildingscience.com/resource ... 004_08.pdf you're in Zone 4, non-maritime - assembly #13 appears to be closest to your wall construction so I would use ONLY latex paint on your inner layer of wallboard with NO OTHER barriers. See the sketch I drew. Some possibly helpful links - http://www.hardwoodinstaller.com/hardwo ... ncrete.htm https://www.nofma.org/Portals/0/Publica ... Floors.pdf http://www.woodweb.com/knowledge_base/I ... loors.html http://www.pergo.com/shop/ProductInfo.a ... uctid=A103 http://www.shawfloors.com/ShoppingExper ... ntStep.asp HTH... Steve