Quick question about water line noise...

Hi All, So after posting in the design forum and getting a killer layout/design from Glenn, I'm about to start construction of the new basement studio. (see design post here http://www.johnlsayers.com/phpBB2/viewtopic.php?t=7925 But before I do, I want to make sure I have all my bases covered. I've got Rod's book to help me out along with all the knowledge I've gained from this forum. (I usually find what I'm looking for with a quick search). The question I have that I can't find the answer to concerns main water line running through my basement. It's PVC and is the main water removal line for the house. It's noisy as hell. Right now I just tell my wife she cannot use any water during sessions. That doesn't go over very well. Anyway, what treatments do I need to do to isolate the sound from this pipe so that when my studio is finished I don't hear rushing water? I'm doing all room-within-a-room construction and am planning on doing one soffit to cover the ceiling obstacles depicted in the following picture. Should I wrap the pipe in fiberglass insulation or use some other material? Please note that I'm talking about the WHITE PVC PIPE IN THE PICTURES Please let me know if this is not enough info and I'll get whatever info is needed. Thanks so much! Ben[/url]

here's a product that works well........ http://www.acousticalsurfaces.com/pipe_ ... d.htm?d=14 Rod

Thanks Rod! Wow, a post from the man himself! Your book is the reason I have only posted on this site a few times. It answered all my other quetsions. Ben

Hey Rod, while I've got you, I've got another quick question. I'm putting gypsum board on my existing deck assembly between the joists per your instructions on pg 66 of your book. It says to use 4d finish nails to temporarily hold the GB in place and then caulk. But what do I use to hold them in place permanently? Is that what the 1x3 ledger board is for? Or do I use drywall screws? Thanks! Ben

benunh wrote:

. . . what do I use to hold them in place permanently? Is that what the 1x3 ledger board is for? Or do I use drywall screws?

Yup -- exactly. 8) --Keith :mrgreen:

Thanks Keith, So, no screws. Just 4d nails and ledger board. Time to get to work! Ben

One more set of questions about this step... What's the deal with the 3/8" backer rod? Just to keep the gyp from sliding back and forth? Will 3/8" fit into the a slot 1/4" wide as directed? Thanks Ben

benunh wrote:

One more set of questions about this step... What's the deal with the 3/8" backer rod? Just to keep the gyp from sliding back and forth? Will 3/8" fit into the a slot 1/4" wide as directed? Thanks Ben

Backer rod is used to help the caulk retain its connection between a gap. On a 1/4 " gap you would also use a ton of caulk to fill all the seams so it cuts down on the price. 3/8 will fit in a 1/4 gap, you want it to fit snug but not crushed too much. Someone mentioned using a pizza wheel type device to insert it (like window screen). You need the 1/4" gap on the drywall to decouple it from everything else, and so you need the backer rod to fill that space.

Ben, I thought I had explained in the book about the reason for backer rod.....and now you have me 2nd guessing myself......... so I had to check - and found that I did miss that explanation - so I'll add that to my list of things to add / modify in the 2nd edition when it comes around. For now though you get an explanation: Although you do indeed save caulk by installing backer rod - this is not the reason to do it. Rather it has to do with the joint either holding or failing. For caulk to adhere properly - and remain sound after curing (and as building movements take place over time) it has to have a joint that is 2 edged. So if you picture the caulk joints drawn in the book - you have the drywall slot - slide in the backer rod - and caulk - with the end result being the caulk attached to the edge of one sheet - and the edge of another - thus 2 points. If you remove the backer rod -= you have a joint now attached at the same 2 points - PLUS after you fill the slot full of caulk - the material at the back that joins the top and bottom - thus you now connect at 3 points. 3 point caulk connections are going to fail based on the movement that takes place over time- thus instead of just streatching the caulk - a shear force comes into play that will cause the joint to fail in it's length......... and it's a lot of money to pay to caulk everything - only to have it all be useless when the joints all fail......... So now you understand the reason why.. and yes - 3/8" backer rod is just fine for a 1/4" joint- stuff it flush to the face with your finger - and then the idea of using a pizza cutter can work - as can the setting tool for spline type screen windows. Just don't crush it in the process.... Sincerely, Rod

benunh wrote:

One more set of questions about this step... What's the deal with the 3/8" backer rod? Just to keep the gyp from sliding back and forth? Will 3/8" fit into the a slot 1/4" wide as directed? Thanks Ben

Not to hijack the thread... but I have a question related to what you just said, Rod. If a person is using RC, if you push the backer rod too far in, it will fall right off the other side of the wall (since its pushed out some distance from the framing etc by the RC). How far SHOULD it be pushed in, IE - how much caulk should one add? 1/2 the depth of the drywall piece? etc Thanks, Jim (Velvet Elvis)

Dan Fitzpatrick posted in detail about his (excellent) experience with backer rod, including where you can buy a lot of it for little money... Check it out. Quote for the day: "Backing rod does stick to the caulk but it doesn't stick to the back of the joint, resulting in a much stretchier joint." -Dan Fitzpatrick --Keith :mrgreen:

Velvet Elvis wrote:

Not to hijack the thread... but I have a question related to what you just said, Rod. If a person is using RC, if you push the backer rod too far in, it will fall right off the other side of the wall (since its pushed out some distance from the framing etc by the RC). How far SHOULD it be pushed in, IE - how much caulk should one add? 1/2 the depth of the drywall piece? etc Thanks, Jim (Velvet Elvis)

Jim, About 1/2 the depth is a good round number... Rod

Just got back from Home Depot. I was ordering the supplies to do this ceiling thing but have a couple of questions. The folks at HD didn't have any idea what Rod meant in his book by "backer rod" and I don't really know either. What material is this and where can I get it? It must be pretty important because it's used in just about every step of studio construction! I was banking on someone at HD knowing what it was, but I don't think I should rely on that anymore :wink: They thought either a wooden dowl rod or rubber spleen?? Also, what kind of caulk should I be using for this? HD again didn't know and they don't have "acoustic caulk". Is there a 'normal' caulk I can use or does it have to be acoustic caulk bought from a specialty store? Thanks! Ben

Ben, Home Depot does indeed carry backer rod. Its in the aisle (at least at my store) where the door weather stripping and such is. It comes in a plastic bag and contains a coil of backer rod. It is NOT in the drywall aisles as one might expect. I can't remember the name on it, but I'm pretty sure that it actually says something like "backer rod", so I'm surprised that they didn't know what you were talking about. I managed to find acoustic caulk by calling a drywall supply house. "Gypsum Supply" is the name of the place that has it in the midwest, but not sure if they are out east at all. They carried (and stock) the OC-175 acoustic caulk. I think you will find that buying acoustic caulk (even if you mail order it) will be at least as cheap, if not cheaper, than buying enough tubes of the "big store" caulk that would work. There are only a couple of brands in the stores that are adequate (I can't remember which ones... because I didn't go that route), but they are far more expensive per ounce than actually buying acoustic caulk. Jim

Thanks for the info, Jim. You can always count on those Iowa folk to help you out! (I grew up in Des Moines and still have a lot of family there) Ben

If you follow the link I included to Dan's post above, you'll see a source where you can buy a lot of backer rod for little money per linear foot. Home Depot carries some of it, but it's hard to find in the store and it's very expensive (small quantity packages). Buy online from Dan's recommended supplier. --Keith :mrgreen:

Thanks for the help and the tips you guys. I've ordered my backer rod (3/8" closed cell). I got 2500' because I know I'll need about 1080' for the ceiling alone and figure I'll use the rest in the wall of the three (and a half) rooms I'm building as I do the multiple layers of drywall. I also ordered acoustic caulk and the lead pipe covering/decoupler. The 45 sheets of 5/8" drywall and 1x3 ledger board came this morning and is in my garage just waiting for the other supplies to show up. So the question now is, can I start putting up the drywall to the existing deck between the joists using the 4d finish nails or do I need to wait until I can do the whole job all at once? aka, will the finish nails really hold the drywall up for a week on their own? Another unrelated question: I had an HVAC guy come out earlier this week and of course he met my requirements with "why would you do that?". But what I want to know from you guys is, can I get the HVAC done before I get my framing up? The reason I ask is because I might not start framing for another 3 or 4 weeks, but in the mean time I still work full-time down there (even with clients if you can believe it) and IT'S COLD!! By the way, I'm going to be running ducts off of the exitsting heating system as it has ample power. Thoughts? ps. I guess I will be starting my official "build diary thread" as soon as I start putting up this drywall. Woo hoo!! Ben