Does anyone know about the "sound dampening" panels at Home Depot?

[Seeker of Rock]

Shopping for roofing materials last weekend, browsing insulation just in hopes they may have some 703, and saw these 4x8 sheets of "sound dampening"(or something to that effect) sheets. I'm still trying to get more transmission loss ideas for my roof. If this absorbs the sound, I'm wondering if I could use it against my trusses, then figure someway of detaching a tongue-and-groove system for the "interior" ceiling. Any good or no?

[daav]

no specific knowledge of that, but just about all insulatory material will have some degree of sound absorbtion. The questions are 'how much?' and 'at what frequency?'. Almost all that stuff has some degree of spec documentation that will give you some feeling about that.

Chances are it will help with some of the higher frequency stuff but not as much at lower frewuencies. But more importantly, it might have some effect, but dollar for dollar and inch for inch it might not be as effective as other things like 703.

If you are having trouble finding 703 type insulation, try looking at other brands and other sources. I live in an area that is nor normally served by huige stores with huge selections (I don't mind this normally actually) and had to look at a commercial supplier of insualtion that carried the Johns Mansfield equivalent. But once found (they are a little operation that had no retail space, you just walk in a door and tell the single guy behind the counter what you want (or have ordered) and he fetches it from the warehouse), they had tons at a reasonable price. The hard pat was seraching all over the net for the right models (these commercial insulation guys had no idea about which lines had the best noise absorbtion) and then knowing htis place existed at all (which only came about because a retail store called the Johns Mansfield home office for me to special order and found out that the commercial sellers were the only ones who could order the stuff).

Good luck,
Daav.

[Seeker of Rock]

Thanks daav. What I was think about using them for was a lightweight alternate to mass my exterior (inter part of the exterior leaf) structure. Roofs are hard to mass because of the gravity factor. So actually to bring transmission loss. Then detaching a more reflective treatment like wood for the interior ceiling that will get direct reflection from the sound. 703 I definitely want to use for bass traps. Do you think I should use them behind my double drywall on the interior leaf as well?

[Seeker of Rock]

So nobody knows about this stuff? Surprising, in this forum. There seems to be a lot of knowledge here. Again, just wondering about it.

[Bill Furnett]

I THINK i've seen it. 1/2" or 3/4" black fiberboard material in 4x8 sheets?
If it's the same stuff, I thought about it momentarily for use beneath drums (Carpet over it) because at 1st glace it looked like a few layers might deaden up the floor under drums (Vibration) a wee bit, but i read something that quashed that idea and yet i forgot what it was. I know it says it will smoke like a MFer if burned and yet i think there was something else that prevented me from further thoughts.

-Sorry-

[Innovations]

Was it dark brown fiberous stuff? I see that at my home depot too. It is called soundboard and it is mostly usefull to go under floors in order to keeps footsteps from transmitting to the floor below. For walls you are likely to do better for the same money by adding another layer of gypsum board or mounting one side on hat channel.

[Seeker of Rock]

It is light brown in color and fibrous. I have to go get another piece of dripedge and some trim boards for my soffits, so I'll check it out closer and report back.

[Bill Furnett]

I'm sorry, i think the stuff i have seen is for roofing, like to reduce the sound of rain or.... Santa? If i go today i'll get some info on whatever this product is as well.

[Be Loveless]

I think what you are talking about is a branded version of homosote board , it is also sold as "soundboard" and other names depending upon the manufacturer. It's primary use is inside of walls as a sound deadenig material. It is fairly brittle and a full board would easily snap if handled incorrectly. I have never seen it used as an interior solution (ie in place of foam or rigid fiberglass) however I helped a buddy of mine build a sensory deprivation tank a few years back and this was the material he used for acoustic deadening inside the tanks walls. For general keeping outside noise outside purposes ( traffic going by, kids playing, people talking upstairs) it was quite effective, I could'nt hear a damn thing in that tank except the sounds my body was generating. I don't think that it would contain a full blast rock band though.

[Seeker of Rock]

If it is that effective, it may help my ceiling. As Rick pointed at a month or so back, this is the weak link in my exterior mass for transmission loss. I may look into using that on the interior of the trusses, then configure some kind of separation device for the gypsum board or tongue-in-groove wood. Haven't really decided on the interior leaf ceiling material yet. I guess the prior would be less expensive. just bought some R-19 batts to go in between the trusses. I wanted R-25 but they were out. Anyway, should keep it fairly cool (in South Florida heat is the enemy, not cold).

[RICK FITZPATRICK]

What I was think about using them for was a lightweight alternate to mass my exterior

Lightweight alternate to mass? There is none Seeker....mass is mass....1 lb is 1 lb whether you have 1 lb of feathers or 1 lb of rock, its still 1 lb. Same with Mass. As far as weight on your trusses, well let me put it this way.

I'm certainly no acoustic engineer, but heres the deal as I understand it. Your studio walls are a two leaf(if you fill the blocks with a certain type sand) assembly with a massive exterior leaf and a lightweight interior leaf, but combined with a isolated slab, I believe you'll have good transmission loss through these wall assemblies as long as you pay attention to all flanking/leakage issues. However, his means in order to keep the ceiling/roof from being a "weak link", it needs to match the transmission loss(TL) of the wall assemblies. But how do you know what your walls TL actually is? You guessed it, you don't. This is why studio designers use TL rated assemblies so they guarantee a certain assembly will meet thier TL goals . They know assemblies are tested in a lab and given a TL rating, usually in STC(Sound transmission Class), which is a "speech" frequency range rating. Music is much more demanding, because of impact and low frequency sounds transmit much more readily. In this respect, your walls should handle these TL grimlens pretty wlell, but who can say exactly... how well? However, your ceiling roof may be impossible to add the mass it takes to match the walls TL IF your trusses arn't engineered for the weight. If you are haveing these trusses engineered, they should be designed to support a TARGET WEIGHT of an assembly that would do the job in the first place. This means specifying what the assemblies are supposed to do, transmission wise. Since you don't know, you're spittin in the wind in that regard. This means going for as much mass as you think you can afford and how much weight you can afford in an engineered truss......BUT

Here is where its gonna get tricky. And please, I'm only suggesting you consider this. You are the only one who knows what your TOTAL circumstance are. When you decided to build a massive wall assembly, I'm sure you didn't know HOW MUCH transmission loss you actually needed, correct? Very few people do, and fewer yet with the skills it takes to translate this data into a building envelope that meets the goal.
In that respect, you designed for a WORST CASE scenario, in which you decided to build the walls out of concrete block thinking if ANYTHING would be
the best material for the job, concrete would, correct?. And you were right as long as everything else is in line with this thinking. But now you have to deal with the ceiling/roof. And this is where "only you know" comes in loud and clear.

Seeker, there is something to consider here. From what I understand, when sound encounters a rigid mass barrier such as your walls, sound will diffract up and over it, which is exactly why massive wall barriers along hiways, to get this diffraction high enough to lower the db profile of sound reaching adjacent residential buildings. And this is the issue. Not being an acoustician, I can't say for sure the exact connotation this implies as it relates to the mass required in your cieling/roof leafs . But it just might be the little acoustical knowlege detail that allows a LIGHTER MASS cieling/roof assembly. However, this doesn't mean HOMOSOTE would do the job either. At least in my opinion.

Here is the bottom line.

Only your ears/knowlege of the situation, can define what you THINK you need. Distance to neighbors, conditions of the space between you and neighbors, type of music, db profile of the music you are recording, and a few other issues have a bearing on this final decision. But here is a few suggestions.

If you are buying premade trusses, they are usually designed to support standard residential construction as per span specs. If you don't know this info, after the fact guessing as far as your trusses support limits are concerned, is asking for trouble if you overestimate their limits. I would find out EXACTLY what these limits are, and if they don't do the job...well, I don't know what to say other than...

I think you are going about this backwards. If you haven't already ordered these trusses, good. Here is what I suggest. BEFORE you order them:

1. DEFINE your ceiling/roof assembly MINIMUM TRANSMISSION LOSS requirement in db.
2. Tranlate this into an assembly that meets this minimal TL need.
3. Calculate weight of these LEAF assemblies.
4. Have structural framing/truss engineered to meet this load support requirement.
5 Order trusses.
6. Build roof/cieling assemblies as per design.
7. START RECORDING


Other than that, you are guessing, plain and simple.
fitZ

[Seeker of Rock]

Rick,
Trusses were designed by me and are in place as well as the entire exterior roof structure. Typically I will design for live and dead loads on structures. This is such a small project that I didn't do the calcs, but know from experience that the design will easily support the roof structure plus interior treatment and with the tie system Iimplemented will withstand at least 135 mph sustained winds. For interior weight, I had planned on double drywall, or single drywall with tongue-and-groove pine exterior. That is the mass I have planned. Could it hold more? Well then I would need to run the calcs but I'm fairly positive they would support quite a bit more weight, but I don't think at this point I need it. If I find I do in the future, it would not be too difficult to add mass of some sort.
Concrete block was used for the walls for two reasons:
1) concrete block is a solid building material and, when constructed properly, has high windload ratings
2) concrete block structures with mortar-filled cells are going to minimize sound leakage more so than a typical wood frame structure, even in a 'connected' area such as my house....the theory of mass.

My particular question was about the 'sound dampening board' and whether anyone, including yourself, was familiar with them and their effects. Again, I plan on drywall and wood for my interior ceiling. If this material minimizes the amount of sound getting through the ceiling better than drywall or sheetrock, then it would be in my best interest to use it instead. That is what I am specifically seeking knowledge on, though I appreciate your time and response.

[RICK FITZPATRICK]

. If this material minimizes the amount of sound getting through the ceiling better than drywall or sheetrock, then it would be in my best interest to use it instead.

Thats what I was trying to tell you...NO, Homosote WON"T do better than drywall, because it has LESS mass. As to the trusses, cool. You hadn't said this stuff before. I assumed you hadn't ordered the trusses yet. And since they carry the load....hence my reply.

[Seeker of Rock]

I didn't order the trusses, I built (still need to add the cross members, so technically still building) them. They are 2x8 rafters on a 2x10 beam that I plan to cross-brace with 2x8, the bottoms of which will be approximately half the height of the distance between the top of the vertical walls to the inside peak of the rafter joints.
So Rick, you think just the sound dampening board will actually bleed more transmission than drywall? I still may look into them not as a replacement for drywall, but in addition to....reality being that I may not decouple the roof structure from the interior ceiling.

[RICK FITZPATRICK]

Hi Seeker. In my opinion, if you have the budget, do the calcs, plan on 2 layers of 5/8 drywall and as much insulation as you can afford. Since you are not planning on decoupling the drywall, I would at least use green glue between layers .

BTW Seeker., I'm a little confused about your "trusses". From what you describe, your roof framing sounds like a standard rafter/ridge/joist assembly, not trusses, right? I also understand your ties if I'm not mistaken. So, whats the problem with weight? Your span doesn't seem that big. If you ARE using a truss design, what is the tie for?

Are you tieing the studio roof to the house roof as well? I can't remember the pics in your original thread.

And one other thing if you don't mind Seeker. Considering the safety topic in a recent thread, would you mind shareing your thoughts/plan on fireblocking the airgap between your exterior and interior walls? Considering this airgap is open to the airgap between the ceiling and roof, it would be wise to address it.
Which now that I think about it, brings up a few questions regarding the wall that divides the studio from the house(garage?) Did you build the studio as a freestanding building or an extension? I also couldn't remember if there was a concrete block wall there or if it was part of the house. Anyway, there I go again. Talk to you later.
fitZ

[Seeker of Rock]

DAmnit man, so many questions...you're forcing me to think.
Let's see, technically the roof design is a center beam rafter with cross-members. Even though the cross members will not be connected at the ends, they will still tie the angled members (rafters) only at a higher location. It is strong, but I may run calcs if I put something like two layers of 5/8" up, though. Glue between layers, eh? Sounds like a good idea. I'm also planning to use washers since the interior layer will be carrying quite a bit of dead load weight. I still may go with tongue-and-groove for the outside layer, though.

What else....the room is connected to a freestanding garage (CBS as well). I plan to decouple the interior walls, which should be fairly easy, and the slab is free-floating as I don't believe the 1/2" bituminuous expansion joint is going to resonate and is separating the slab from the exterior leaf block walls. Ceiling is the only thing I may take a shortcut on, in full cognizance of the weak link theory. I can always change it if it doesn't sound right.

Firewall...the existing wall of the garage that this was built off of is a firewall. The ventilation gap in the ceiling of the new room won't require a firewall, only where coupling new to existing structures and the existing garage wall (firewall) is concrete all the way up to the pitch.
Airgap between interior and walls and exterior structural walls....I had planned on using 703 fiberglass, not only for frequency control but as well for thermal insulation, which I think it is originally produced for. Nothing else planned for fire retardancy except accepting if I am unfortunate enough to have a fire, the cbs walls will be standing. Replacing a $300 roof will be the least of my worries, as the equipment will be the big hit. But unless I have an interior designed of non-combustible materials, I will have to take that chance.

I'll take some photos tonight and post the progress so far.

[Seeker of Rock]

I wonder if what I saw at Home Depot was the 'fiberboard' John Sayers talks about sandwiching between drywall layers? It certainly fits the physical description. If so, it sounds like I may want to put it between the double drywall. If not, I wonder where I could find the 'fiberboard' for purchase?

[RICK FITZPATRICK]

Seeker, in my opinion the ONLY thing you should put between layers of drywall is GREEN GLUE...not just any glue...but GREEN GLUE. Period. Tests have confirmed that using it makes 2 layers act as one, and believe me, there is a BIG difference.

http://www.greengluecompany.com/

[Seeker of Rock]

Alright then, done and done. I'm not familiar with green glue, but I'll do a search. Is it a specialty item or do you think a local hardware store would carry it?

[tarnationsauce2]

is it this stuff?

[Seeker of Rock]

I can't tell for sure, but yes that looks similar. But the stuff at HD is only 1/2" in 4'x8' sheets. That stuff looks to be what, 1" or more?
I just went to get some 2x4s and I should've taken a pic of it to post.

edit: I took another glance. In my mind's eye, the HD product seems to be a little more dense. Maybe it is just because of the difference in thickness.

[Obi-Wan zenabI]

I just did my 20 by 30 foot loft above my detached garage in this stuff, and covered it with 5/8ths sheetrock.

I'm building a combination rehearsal/recording/ hi-fi listening/ library. On the cheap. Lots of compromises being made. I'm not in a quiet neighborhood, we're near a main Motorcycle criusing avenue here by the beach, and you can hear I-95 a mile away...

I can't give you the results yet as I still have the last four or five sheets of drywall to put up, then taping &c. BUT I really feel like it was worth it. Even though the drywall is screwed to the studs through the soundboard, I really feel like it will deaden transmission of sound over a pretty wide range of frequencies.

LF stuff is bound to still transfer itself along the screws to the studs, but my sound reduction needs aren't that big. (Note that I do play mostly Jazz.)

I could also hang it solo (my wife's pregnant...) b/c it was so light.

cost me nine bucks a sheet, so about equivalent to a layer of drywall.

Edit: This garage really does have truss construction, spaced pretty far apart, 24" O.C. I think.

[RICK FITZPATRICK]

Hey Seeker, here is something you should read. Good info.

http://www.johnlsayers.com/phpBB2/vi...7431e567ac6289

[Seeker of Rock]

Rick, that was good. I think I'm going with something a little different though. I went ahead and bought some of the "Hush Board" as it is called, and am going to give that a shot with tongue-in-groove for the exterior of the interior leaf. No physical separation of the roof/ceiling structures, but I'll cough it up and be the guinea pig. My wife always says I'm a pig, anyway. At least we'll have some definitive idea of what the stuff does and whether it is worth the $72 I paid for it.

[Mo-Kay]

I'm sorry, i think the stuff i have seen is for roofing, like to reduce the sound of rain or.... Santa? I

Santa?


now that's mass for ya