Any suggestions to maximize isolation?

sammy87 · Post by **sammy87** » Wed Sep 21, 2005 11:38 am

Plan below.

sammy87 · Post by **sammy87** » Wed Sep 21, 2005 11:40 am

This was supposed to be at the bottom of the above message, sorry.

A: neighbor's flooring nailed to our existing ceiling joists

B: existing 13" x 3" ceiling joists, 16" on center

C: existing conduit and gas pipes which run along our existing ceiling or up from the basement, through our space and into the apartment above. This is the biggest reason why I don’t want to use the existing structure as an outer leaf. Soundproofing around all these penetrations (over a dozen, maybe two dozen) would be a colossal headache if not impossible.

D: plaster and lathe on ceiling joists, there are huge holes in this layer. Nearly a quarter of it is missing.

E: New 2" x 6" ceiling joists, suspended from the existing joists with 2" x 4" strips. This would be done to get below the pipes and conduit so that we can have an outer shell without penetrations. Would it be better to suspend this with something more resilient than 2x4s? How much space should I leave here? Smallest possible, Biggest possible, doesn’t matter?

F: plaster and lath

G: brick outer wall. Since this is not going to be our outer leaf, would it be a good idea to vent this wall, if possible?

H: 2 layers of 5/8" drywall, Should we hang three layers? I'm worried about the new ceiling supporting the extra weight.

I: New 2x4 steel studs for the outer leaf. Again, we need to build a new wall here to avoid penetrations through our outer shell. Would wood be better? Should these be built on the existing floor, or should we put down something to seal it first?

J: 2 layers of 5/8" drywall. I know these should be on the other side of the stud, but I can't figure out a good way to get drywall up when you are right next to a wall. Ideas?

K: Inner leaf ceiling joists. 2" x 6", 16" on center. Would 24" be better? How much of an air gap is appropriate here? We've got 12' of height to work with, so I'm willing to leave as much space as necessary.

L: 3 layers of 1/2" drywall. Should I use 5/8", the other leaf uses 5/8" so I figured we should hang something different on this side.

M: inner leaf 2x4 stud wall. 16" on center. Again, How much space is appropriate from here to the outer leaf? I can afford to leave a larger than normal air gap here as well.

N: 3 layers of 1/2" drywall.

O: New floor joists. How much space should we leave here? What kind and how much material should we use as flooring. We can't use concrete. I don't think the existing floor can support the weight.

P: Rubber pucks to float the floor on.

Q: existing floor beams

R: existing flooring, definitely not airtight. over a 5 1/2' basement.

Where should we insulate? Between which layers and how much should we use?

Post by **sharward** » Wed Sep 21, 2005 12:06 pm

Oh man, I know the feeling you have -- your first detailed illustrations and a barrage of questions, now nervously awaiting a response and cringing at the possibilities!

Well, nicely done. I think you've painted a great picture and communicated your questions really well.

Beyond those kind words, I think I'll take a step back and see what some of the experts here (and some of the not-quite-experts-but-really-smart-anyway people) have to say about your difficult situation.

If you have photographs to complement your illustration, that would be really helpful. You've described some conditions on that outer leaf that probably need some visual elaboration.

Now if you'll excuse me, I need to get out of the office here so I can go home and kiss my garage, because it seems infinately more friendly to studio building than that challenging old building of yours!

--Keith

sammy87 · Post by **sammy87** » Fri Sep 23, 2005 10:34 pm

We are going to start construction in the live room on Sunday. I would be eternally grateful if someone were to take a look at the plans above and give me some advice.

Thanks,
Sam

Post by **sharward** » Fri Sep 23, 2005 11:49 pm

Sam, I realize you're in a big hurry to start building stuff. However, having seen many projects on this forum rush into construction, only to have serious and sometimes irrepairable problems later, I have to go on record recommending that you not build anything until your plans are firm... And that will take time and patience.

AVare · Post by **AVare** » Sat Sep 24, 2005 1:08 am

sammy87 wrote:We are going to start construction in the live room on Sunday. I would be eternally grateful if someone were to take a look at the plans above and give me some advice.

Great news! I have even beter news for though. You have already started.

Good studio construction is 90% planning and 10% building.

Andre

sammy87 · Post by **sammy87** » Sat Sep 24, 2005 4:06 am

sharward wrote:Sam, I realize you're in a big hurry to start building stuff. However, having seen many projects on this forum rush into construction, only to have serious and sometimes irrepairable problems later, I have to go on record recommending that you not build anything until your plans are firm... And that will take time and patience.

Unfortunately, we are under an enormous time crunch. If the room isn't built by January 1st, it won't be built at all. We don't have the luxury of time. I'm going to restate my questions and concerns and hope that someone responds to them by Sunday.

1. Can we safely ignore the existing stucture as an outer leaf to avoid the penetrations? If not, will venting help at all?

2. Should we suspend the new outer leaf ceiling from 2x4s or something more resilient.

3. How much space should we leave between the outer leaf and the existing structure?

4. Should the outer leaf wall be built on the existing floor or should new flooring be placed down first?

5. 2 or 3 layers of drywall on the outer leaf?

Sam

knightfly · Post by **knightfly** » Sat Sep 24, 2005 9:44 am

Sam, I know all about time crunch; I'll try to cover all your q's tomorrow afternoon, before I go in for my last 12-hour night shift... Steve

knightfly · Post by **knightfly** » Sun Sep 25, 2005 9:41 am

OK, I'll start with your last set of questions, and add points I'm most concerned with as I think of them; also, I'll be around a few times a day starting Sunday afternoon and will try to keep a running commentary going til you're clear on all points.

1. Can we safely ignore the existing stucture as an outer leaf to avoid the penetrations? If not, will venting help at all?

No, and no. This thread

http://forum.studiotips.com/viewtopic.php?t=1198

shows the effect of a VERY vented leaf. Since you can't IGNORE the effect, you have to OVERCOMPENSATE for it or seal the existing and beef it up so it works as one of the main leaves; this doesn't sound practical in your case (pipes, missing sections, etc)

2. Should we suspend the new outer leaf ceiling from 2x4s or something more resilient.

Before you do this you should REMOVE virtually ALL the old ceiling, this is creating a QUAD leaf which will hurt iso even more than a triple. Then, you will need at least three, and four if possible, layers of 5/8 gypsum for your outer ceiling leaf; those joists should have no problem with that much weight, you're adding about 11 PSF for 4 layers of 5/8. I'd hang your 2x4's down every 4 feet and pay particular attention to tight nailing. 2x6 sub-joists will be plenty to hang 4 layers of 5/8 on.

BTW, most codes require metal framing for commercial space; do you plan permits and insurance, or are you financially suicidal?

3. How much space should we leave between the outer leaf and the existing structure?

As little as possible without hard contact; the resulting resonance will have to be compensated with extra layers in both new leaves; minimum 3 layers (5/8" again)

4. Should the outer leaf wall be built on the existing floor or should new flooring be placed down first?

Need more info on the floor first. And since the floor would have to happen first, we need to solve this as top priority - I need actual measurements of joist spacing, joist size, maximum UN-supported span of the floor, and details of the 5-1/2 foot basement(for dwarfs??!?) space - is it possible to add support columns under this floor (in basement) to improve span? Is the side wall of the basement continuous into the upstairs neighbors' space? Is it solid concrete, or brick, or?? Is there any other reason to soundproof your floor, other than flanking possibilities thru basement, up walls and into neighbor space?

5. 2 or 3 layers of drywall on the outer leaf?

Covered earlier.

Off to last night shift soon, I'll try to check on this tomorrow morning briefly and more as needed - please check thru your answers on each post to make sure you've answered EVERY question so we can keep from slowing your project down waiting for the next round... Steve

BTW, looks like the minimum span for your live room inner ceiling would be about 19 feet - there is no way in hell you'll span that with 2x6's, no matter WHAT spacing. For 24" centers, you'll need 2x12 doug fir, Std & better to support 3 or 4 layers of 5/8" gypsum. For 16" centers, 2x10's would work. That much weight, resting on your inner walls, DEMANDS that there be serious support UNDER your floor at those points -

Just calc'd basics for interior frame, 3 layers gyp, etc - it's looking like your floor at the perimeter would need to support around 260 pounds per square foot. This is immense. I'll re-check my calcs ASAP, but meanwhile don't even think of building this til we get things sorted out.

sammy87 · Post by **sammy87** » Sun Sep 25, 2005 3:08 pm

Steve, thanks for taking the time to help us with this project.

knightfly wrote:Since you can't IGNORE the effect, you have to OVERCOMPENSATE for it or seal the existing and beef it up so it works as one of the main leaves; this doesn't sound practical in your case (pipes, missing sections, etc)

Do you mean overcompensate with mass? ie. adding as much drywall as possible to the new leafs?

I'll get more details on the floor/basement construction at the studio tomorrow, and I'll post them here late afternoon. In the meantime, I'm going to start pulling plaster and lath off the ceiling.

Thanks again, this is a great start.
Sam

Post by **sharward** » Sun Sep 25, 2005 4:50 pm

sammy87 wrote:
knightfly wrote:Since you can't IGNORE the effect, you have to OVERCOMPENSATE for it or seal the existing and beef it up so it works as one of the main leaves; this doesn't sound practical in your case (pipes, missing sections, etc)
Do you mean overcompensate with mass? ie. adding as much drywall as possible to the new leafs?

Yes, I believe that's what he means.[/quote]

I'll get more details on the floor/basement construction at the studio tomorrow, and I'll post them here late afternoon. In the meantime, I'm going to start pulling plaster and lath off the ceiling.

Sounds good -- and it would be great to see some actual photos of this joint!

--Keith

sammy87 · Post by **sammy87** » Mon Sep 26, 2005 7:54 am

knightfly wrote:I need actual measurements of joist spacing, joist size, maximum UN-supported span of the floor,

Floor joists are 5 1/2" x 3 1/2" spaced 16" on center. The maximum unsupported span is 6', but most of the support columns are placed 4' apart.

is it possible to add support columns under this floor (in basement) to improve span?

It is possible to add supports under the south half of the live room. The north half is above a tiny crawl space, it would be difficult to add support here, but not impossible.

Is the side wall of the basement continuous into the upstairs neighbors' space? Is it solid concrete, or brick, or??

The basement walls and floor are solid concrete up to ground level. The exterior brick wall is built on top of the concrete and extends to the roof.

Is there any other reason to soundproof your floor, other than flanking possibilities thru basement, up walls and into neighbor space?

I don't see any other reason.

I started pulling plaster and lath off the ceiling today. We are going to have to get all that debris to the dump before we start any actual construction. I doubt we will be able to build anything for another week or two.

Sam