Trouble getting started and understanding...new construction

Myriad_Rocker wrote:

On another note, I met with a potential builder today. He asked if, instead of fiberglass insulation in the walls, could they blow in a cellulose insulation. He said that it would probably cover every nook and cranny of the wall so no air would escape, etc. As oppose to fiberglass, which would leave some gaps.

Cellulose insulation is made primarily from recycled newspaper with a chemical that aids in fire retardation. It would be fine. The only thing may be that you could blown the exterior wall, but once the interior(assuming a room in room build is being considered) is built, how would you blow that in? You wouldn't. But as a thermal barrier that minimizes air leaks, it may be something worth considering. Good luck, Brien

Cellulose insulation can be installed air tight??

Do I need to consider a slot resonator(s)? I plan on putting some large bass traps in the corners of all the rooms but I'm worried that, in the CR, I'm going to have things all over the place when I do a room analysis. I guess all I can do at this point is just the best I can during the build. Then worry about treatment later, huh? As oppose to the inside-out ceiling, why not take the same approach as with the walls? Double up on the drywall with Green Glue between and then put fluffy pink insulation on top in the trusses. The actual roof of the building should act as the second leaf, right? Then, on the ceiling itself, suspend some rigid fiberglass panels, put treatment at the first reflection points, and straddle the corners where the wall meets the ceiling. Thoughts?

Just bumping my question about the ceiling.

As oppose to the inside-out ceiling, why not take the same approach as with the walls? Double up on the drywall with Green Glue between and then put fluffy pink insulation on top in the trusses. The actual roof of the building should act as the second leaf, right? Then, on the ceiling itself, suspend some rigid fiberglass panels, put treatment at the first reflection points, and straddle the corners where the wall meets the ceiling. Thoughts?

Well, yes, that's a "normal" ceiling, not an "inside-out" ceiling. If you don't need the extra height gained by doing it inside-out, then sure, you can do it that way. The only thing you gain by inside-out construction is the extra space. If you don't need it, then you don't have to do it! - Stuart -

OK, so I did a bit of research on cellulose insulation, and I learned a few interesting things! Brien is right: cellulose insulation actually does have useful acoustic properties, pretty much the same as fiberglass, so I take back my earlier comments about it not being much use acoustically, and also my comment that your builder was trying to cut corners. So theoretically you could use it... HOWEVER! (You just KNEW there was a big "however" coming up, didn't you! :) ): However, there are many false claims made about it that you should learn about, that might change your mind. I found this comparison to be very interesting and informative: http://www.owenscorning.com/worldwide/a ... 11529E.pdf In summary, it simply ain't anywhere near as good as it is made out to be, in many areas! In addition to all the above, as Brien pointed out, it would be practically impossible to blow it into some places in your wall. So, considering all of the above, I think my earlier advise still stands: Stick with fiberglass or mineral wool. - Stuart - Edited to add: I just found another reason why using this stuff is a bad idea: Like I suspected, it can bridge the air gap, short-circuit, and reduce isolation: This comes from a 2001 paper published by the "Institute of Research in Construction of the National Research Council of Canada":

With the exception of sprayed cellulose, the best transmission losses were obtained when the entire cavity of the partitions were filled with a sound absorptive material. When the entire cavity is filled, caution must be taken not to use a material that is too dense, otherwise a mechanical coupling could occur between the two sides of the partition which could result in a degradation of the sound isolating performance of the partition, as was observed in the case of a partition whose cavity was filled with sprayed on cellulose.

Soundman2020 wrote:

I just found another reason why using this stuff is a bad idea: Like I suspected, it can bridge the air gap, short-circuit, and reduce isolation:

You are wrong in your assertion that "using this stuff is a bad idea". ANYTHING crammed into a cavity can bridge the gap...even the fluffy pink stuff. If we stuffed YOU into a cavity, it could short circuit the isolation just as easily. "With the exception of sprayed cellulose, the best transmission losses were obtained when the entire cavity of the partitions were filled with a sound absorptive material." The partitions...can you read that? "When the entire cavity is filled," Entire cavity" Can you read that? Man, get a job....

What is your problem, Brien? Having yet another bad day? :) If you don't like the scientific research papers regarding this product, then that has nothing to do with me! Go do your own research, if you think their findings are wrong. OR maybe just read what they ACTUALLY wrote, instead of what you THINK they wrote...

The issue is not being able to read what is in front of you. It is clear but yet you find ways to twist it up to satisfy what it is you are thinking you see.

"With the exception of sprayed cellulose," I mean, really, how much more clear does this have to be? Face it man, your just wrong. I use the word man because I really do not know anything about you that I can hang a hat on. Argumentative egotistical brat just takes too long to type. Live with it.

You have the potential to be good help Stuart. Why you blow it on your ego and lack of attention to detail is what pisses me off. The new comers may think you hung the moon with your "detailed" 4 posts a day, but at the end of the day, it's just parroting. And heaven help the poor sob that suggests anything other then what you can see through your little filtering system. I want to help out here, with my background, I could. But I'm not going to arm wrestle some guy just because that is the only form of moderation this forum has left. I stay because I love what I do, building is all I know how to do and even after 30 something years, it's full of surprises. But it is just too difficult to be around when a man cannot say a word to a user without it having to pass through your filtering system as supported or not. It is crazy. It is crazy to watch and it is crazy to be a part of. And I am crazy for staying here.

:?:

And I am crazy for staying here.

Nobody is forcing you to... :) You can leave any time you want.... And probably, would not be missed too much by many.... And... my, my, my! That little temper tantrum does seem rather strange!.. How come you suddenly blow up like that, violating the forum rules about personal attacks, for a plainly silly reason? (That you were not able to read and comprehend what the reports say). Not sure what your problem is, but I'm certainly not going to engage in your little pissing match! That would be silly... it seems like your fragile ego took a major blow from being proven wrong about your claims (yet again....), so that's not something you can lay on me, as you seem to be attempting here. I didn't write those papers: others did. You might not like what they found, but that's not on me! If you have a beef with teh research they did, and the results, then go blow steam at them, not at me.

X, what's the deal, man. Take another lemon and enjoy the weather (it's a sunny day here in Holland :) ) Maybe you should take some distance before getting TOO personal. It's really not worth it. Cheers!

It isn't personal. It is this. I do not like being beat over the head with information, especially when it is blatantly incorrect. Is that personal? Does incorrect information multiplied by more documentation make it less incorrect?

Okay, let's simmer down, now. Don't derail my thread for the sake of your arguments. :mrgreen: Let me ask this, then. So...this blown in cellulose stuff...it would be good to use instead of the fluffy pink stuff?

Derailing is the farthest from the point, the confusion that now exists IS the point. You can use fluffy pink stuff or you can use blown in cellulose...for an exterior application, blown in will produce a better overall air seal. But you can use either one you wish.

Part of the confusion is not realizing the difference between "blown" and "sprayed". Blown cellulose has very low density. Sprayed cellulose has much higher density and a bonding agent (glue or starch). Sprayed cellulose is a mixture of blown fiber and a liquid, either glue or water depending on whether the fiber has an adhesive built in or not, that mix together in the air before hitting the surface to be sprayed. Blown fiber is dry fiber with no or very minimal liquid (used for dust reduction) that is normally blown into sealed up walls or between the rafters in attics. very low density, very fluffy. Check the dimensions of your live room, it looks close to a square to me this will give you problems. Steve

Good post. "using this stuff is a bad idea" is the beginning. Blown or sprayed, neither of the two installation procedures matter. But recall that we are talking about a vertical wall. Cellulose is cellulose. It is what it is. I appreciate your input, Brien

Cold wrote:

Check the dimensions of your live room, it looks close to a square to me this will give you problems.

I seem to recall reading that the dimensions of my live room didn't particularly matter????

The dimensions of your live room do matter, just not as much or in the same way as your control room. Symmetry is not needed, as you are not worried about balanced imaging from a stereo source. Asymmetry is sometimes helpful as it will aid in different "sounding" areas in the same room. But a square room is going to create nulls and peaks that you will have to be aware of every time you set up a mic, position instruments, arrange musicians... It creates an avoidable headache. Why not aim for a golden ratio or something close to it if possible? You're building from scratch, make the most of it. As a side note: On a purely practical level I would not use any form of blow in as cavity fill between double stud walls. Too damn messy if you ever need to access that space. It would have to have a large benefit for me to go that route. And I spray insulation and fireproofing as a day job! Steve

Cold wrote:

Why not aim for a golden ratio or something close to it if possible? You're building from scratch, make the most of it.

Does Rod's book mention "golden ratios" for live rooms? I may be building from scratch but I need to be budget minded and practical. I'd love to hear more about the ratios for live rooms.

Cold wrote:

As a side note: On a purely practical level I would not use any form of blow in as cavity fill between double stud walls. Too damn messy if you ever need to access that space. It would have to have a large benefit for me to go that route. And I spray insulation and fireproofing as a day job! Steve

Steve, The idea is not to completely fill a cavity between panels. Never is and never was. As you should know, with your background, any form of sprayed cellulose far far exceeds typical batt type insulation. It is a better thermal barrier, it is a better at sound attenuation and it fills the voids and prevents air leaks that batt insulation can just not achieve. In an exterior wall, it is just the right thing to do. As to ever having to access the void in between a room-in-a-room type wall construction, it's not a place that people tend to open back up, ever ;) But whatever the OP wants to do is fine, batt or sprayed in urethane, blown in cellulose, etc. As long as he knows his options. I like the 1.68 golden ratio you bring up as well, for a room dimensioning function. Most here try to apply "room ratios" re: MM Louden or LW Sepmeyer. Everyone should know they have many options.

Hi Brien, I'm going to leave the cellulose topic for the moment as there are a few points that I'm not 100% certain on, regarding it's usage within a double stud wall configuration. Points I should know but do not. I will do a little research. I do agree with you though, that as far as my understanding goes, a double stud wall is not completely filled with insulation. OP, Good room ratios are good room ratios- control room, live room, listening room, living room...... Think about this a little bit, have you ever been in a room where a specific frequency's relative volume changes as you move around within the room? Do a little reading on room acoustics and it should make sense. Steve

Cold wrote:

OP, Good room ratios are good room ratios- control room, live room, listening room, living room...... Think about this a little bit, have you ever been in a room where a specific frequency's relative volume changes as you move around within the room? Do a little reading on room acoustics and it should make sense.

Well, using the Sepmeyer #2 ratio, my live room would be 12 x 15.36 x 18.48 That means more walls, which means more money. I'm still waiting to hear back from two builders on the cost of doing this project. I'm thinking the estimate is going to blow the doors off of my budget. I have attached a new picture for the newly suggested layout using the ratio I noted above. I tried to pick a ratio that would allow me enough room to work with. However, it now requires you to go through another set of doors to reach the vocal iso booth. Ugh. This does, however, solve my problem of needing an exit point on the other side of the building to get to code.

I think you have way too much area as hallways. I don't have any suggestions on how to arrange your rooms more efficiently, just an observation. Now is the time to play with all the possibilities!