read the stickys/posts, building a jamhouse, request advice

Building a jamhouse here in my new backyard in central Texas. Will be 20' from neighbors home with a cedar fence in between. I live near Austin, a major city with many building supply stores. I have an able and reasonably priced carpenter and some helpers, a budget of about $3-5k depending on hvac and other expensive options. Want to build a structure about 20 x 20. Exterior hardiplank 4 x 8 sheets, plus some type of sheathing. Thus, the majority of my budget can be for materials as I have some semi-experienced labor to assist for free. Carpenter is experienced in home repair and construction but not in soundproof structures. Here's my questions: 1. best recommendations and/or link on floating ceilings and hvac options. Don't quite have all this under grasp yet. 2. plan to sheetrock floated walls and ceilings. 3. Best electronic recommendations. Basically, not a recording studio, just amatuer recording and rock/blues jamming and lots of drumming since I'm a drummer. Not stage volumes but like what you might find in a commercial rehearsal studio, maybe a little less. Plan to have an HVAC. 4. How thick should my slab be? Is there any benefit from having a 1' wall extend up from the slab all around the slab? Does this stop low frequencies? I saw one post where a fellow had a slab like that and I couldn't tell if it was by design or just what he had to build on already. 5. SHould I use a layer of vinyl sheathing between sheetrock layers? 6. Does the "acoustic glue" product advertised by the folks who make quietwood and quiet rock work? is it worth it over regular caulk? Finally, should the layers of sheetrock be glued together? BTW, I don't plan on using quietrock or quietwood, I just saw the glue product advertised. 7. Building a floated wall as I've seen pics of, with an inner and outer leaf of 2"x4"'s with a 2" gap between, is it better to have an air gap or to use insulation for max sound stoppage? 8. TELL ME WHAT YOU WOULD DO DIFFERENT IF YOU HAD TO DO YOUR PROJECT ALL OVER AGAIN Thanks for the advice. It's a start, I have a long way to go.

Oh and KNightfly, this looks to be part of my answer. Could you break it down for me? Replace Keith's bricks with a PT 2x4 perimeter frame on 3/4 OSB on PT 2x6's on 1" EPDM, fill that 2x4 perimeter with concrete, (stuff the 2x6 joist cavities with insulation first), and you have a floor that will isolate any frequency you can hear, for almost a buck less per square foot than a "wooden wannabe" -

Welcome Groovemastergreg! I have one big concern right off the bat, that being the budget. Have you done any budget analysis? In my neck of the continent, self-standing buildings cost 50-100$/ft^2! I can easily see 2 - 3k going just on the HVAC. It would a top ofthe line HVAC system, but not excessive for such a building! If what you wrote si the total budget, I can't se it happening. Hopefully I am missing something here. Andre ps: Thanks for the help your state is giving to the victims of Katrina.

Yeah, the air conditioner and ventilation system for my little 120 square foot jam space inside my garage will set me back about US$4,000. Granted, that solution is going to be top-notch, but after months of deliberating, anything less would have been inadequate and would not have met the combination of isolation requirements and city building department bureaucrats' standards. You're planning a room about three times larger than that and yours will be freestanding! :shock: Sorry, but I can't see how you can make that happen, even if you stole half your materials and compensated your laborers with the cheapest beer you could get your hands on. You're going to have to either raise your budget, or reduce your square footage, or quite probably both. In case you don't know, I'm the "Keith" referenced in that quote. And also in case you don't know, I abandoned the floating floor, opting instead to do an isolated slab, which will not be cheap or easy. Now that we have some context, I'll take a stab at your questions:

1. best recommendations and/or link on floating ceilings and hvac options. Don't quite have all this under grasp yet.

Your best bet will be "room within a room" with an inner ceiling that sits atop your inner wall frames. If you do this, you don't need any resilient channel (a.k.a. "RC") so you don't have to "float" the ceiling -- it's already decoupled if done this way.

2. plan to sheetrock floated walls and ceilings.

You may see varying opinions on this, but I don't think you need to float if you are in a standalone building.

3. Best electronic recommendations. Basically, not a recording studio, just amatuer recording and rock/blues jamming and lots of drumming since I'm a drummer. Not stage volumes but like what you might find in a commercial rehearsal studio, maybe a little less. Plan to have an HVAC.

I'm not qualified to answer this because I know zilch about recording. All I'll say is, I really hope your budget doesn't include this aspect of your project! :shock:

4. How thick should my slab be? Is there any benefit from having a 1' wall extend up from the slab all around the slab? Does this stop low frequencies? I saw one post where a fellow had a slab like that and I couldn't tell if it was by design or just what he had to build on already.

A flat slab with deeper footings should be fine... But seek some advice from foundation experts in your neck of the woods. Make sure it's rebar reinforced and I'd say 6" thick.

5. SHould I use a layer of vinyl sheathing between sheetrock layers?

Absolutely not. Read this.

6. Does the "acoustic glue" product advertised by the folks who make quietwood and quiet rock work? is it worth it over regular caulk?

Comparing a glue to a caulk is apples:oranges. That being said... That company's products have been slammed here over and over again. Here's an example. If you're asking if acoustic sealant is better than regular caulk(s), the answer is an unequivocal "yes." However, shop carefully, as many sellers assume you are a chump -- you can usually get a good deal if you shop around. I bought 60 commercial-sized 28-ounce tubes for just over $4 each here in town. People here have purchased it for less than that.

Finally, should the layers of sheetrock be glued together? BTW, I don't plan on using quietrock or quietwood, I just saw the glue product advertised.

OK, good -- glad you're not going to try to buy those ridiculously overpriced panels. :) As far as the glue goes, I don't think you need to worry about that. You need mass-air-mass. Keep reading and studying here and you'll come to the conclusions that there really aren't any "magic" products. You just need lots of mass, some air, and lots more mass, in each direction (except maybe down in your case), and you need it to be air tight of course.

7. Building a floated wall as I've seen pics of, with an inner and outer leaf of 2"x4"'s with a 2" gap between, is it better to have an air gap or to use insulation for max sound stoppage?

Insulation doesn't really stop sound. What it does do is dampen the wall -- think of an object vibrating that you press your hand against to minimize the vibration. In the mass-air-mass equation, insulation counts as air -- it doesn't make the air any more effective, it just helps the mass out a little.

8. TELL ME WHAT YOU WOULD DO DIFFERENT IF YOU HAD TO DO YOUR PROJECT ALL OVER AGAIN

The main thing I would do differently would be to have adjusted my expectations at the beginning of my planning stages to anticipate the amount of time it realistically takes to learn all the fundamentals of sound isolation, and building codes, and how they often collide with each other. We bought this house in the Spring of 2004, and I thought I'd be done by Christmas! :lol: Here it is in September 2005 and I've just barely begun construction. Now tell us more about that budget of yours... Is that all you have, or all you are (or were) willing to spend? Finally, you've thoroughly studied the "Reference Area" announcement, right? Because you know there will be a quiz! --Keith :mrgreen:

OK so back to the budget board. I do have more money to spend, and knew hvac would be expensive. Maybe go with a smaller room, less sq feet, and just one big room. Or one medium sized room. And the amatuer recording part...I'm talking about putting up a dat with a stereo mic or maybe hooking up mics to a multi tracker, either a tape or a pro tools unit a friend has (occasionally). What I meant by amatuer recording was basically recording jam sessions very informally, i.e., acoustics are not really the concern, sound blockage is. Great! Let me digest this and get more intelligent and I'll post again. Thanks again for all the help and eye openers already! Greg in Austin

Glad to help, Greg. Spend some time in my thread and you'll see a wastebasket full of crumpled up paper. ;-) Meanwhile, enjoy this, realize that the road is long and twisted (not unlike some of us :twisted:), and be reassured that we're here to help get you unstuck when you need it. --Keith :mrgreen:

nice post keith. groovemaster, you definitely do NOT want to glue your sheetrock panels together, because this will lower the resonant frequency (aka coincidence frequency) of the assembly. the coincidence frequency is where the panel itself performs most poorly (deviates from normal straight-slope mass law). unglued panels = several, high-frequency coincidence frequencies glued panels = one, lower-frequency coincidence frequency higher frequency is better because in general any wall performs better at high frequencies.

sharward wrote:

Insulation doesn't really stop sound. What it does do is dampen the wall -- think of an object vibrating that you press your hand against to minimize the vibration. In the mass-air-mass equation, insulation counts as air -- it doesn't make the air any more effective, it just helps the mass out a little.

keith, as far as i know, this isn't quite right. although i'm no expert either! :) what keith says is true about how insulation helps the wall. BUT, insulation DOES stop sound too. By having the sound waves travel through insulation, friction is created which converts sound to heat. This is how insulation works to absorb sound on the outside of walls and it works the same way inside walls. one of the canadian research reports i have read, i'll try to provide a link later, shows that 100% fill is better than partially filled. some people worry that the insulation will couple the leaves so they leave an inch of space. this probably isn't necessary IMO unless you are REALLY packing the insulation in and makes the wall less fire-resistant. Brian Ravnaas has indicated that, as a rule of thumb, every inch of insulation added to the inside of a wall is like adding a virtual inch of extra space between leaves. so if you fill the cavity you have in effect doubled the space between your leaves, which lowers the mass-air-mass resonance (which is VERY good). Hopefully i'm not misquoting Brian here ... i really should look up the post on studiotips where he told me that. but anyway, that is how Brian's resonance calculator works. actually as i recall the basic equation for calclulating mass-air-mass resonance uses a different constant depending on whether insulation is used or not. I'm feeling a bit lazy today so I can't be bothered to annotate this post right now. But if you want more references on anything here let me know and i'll follow up. dan

Greg, here's some ancient history that may be relevant; there may be a few dead links, but the last page (I hope) should be correct. Right in your neighborhood, the email addy for Jim was correct last I checked. http://www.homerecording.com/bbs/showth ... ge=1&pp=20 You might be able to score a "2-bit tour" if you tell Jim Knightfly sent you... Steve

Dan Fitzpatrick wrote:

keith, as far as i know, this isn't quite right. although i'm no expert either! :) what keith says is true about how insulation helps the wall. BUT, insulation DOES stop sound too.

Thanks for correcting me, Dan. :) I guess I've gotten M-A-M drilled into my head so much that I assumed "airy" insulation didn't stop sound. :roll: