Voiceover studio design for guest house structure

I've been lurking here for months and reading, reading, reading all the incredibly helpful information in the stickies, FAQs, and discussions. I hope I've done my homework to its fullest before posting this build proposal. What I request is just to get some feedback on the design and choices of materials. Maybe point out the weak spots or the parts that are over-engineered. The location is in Bel Air, CA somewhat close to busy Sunset Blvd and 405 (.5 miles away). My biggest concern are helicopters penetrating the booth. The room has a concrete floor with an existing thin vinyl flooring glued down. Should this be removed? I don't have details of the ceiling in the sketchups, but plan to use Kinetics ICW hangers to hang the ceiling from newly installed joists. Here's what I have: Booth Construction Dimensions (booth interior) East wall- 11’ North wall- 7’6” West wall- 11’ 7’2”- Gypsum board 3’- Glass South wall- 7’6” 4.5’- Glass 4’- Door framing Ceiling- drop from existing roof structure Soffit- 4’ x 8’, extends ceiling line from closet into main room Glass Assembly for corner wall Exterior panel- Laminated glass 5/8” thinkness with .09mm lam Interior panel- Laminated glass 1/2” thickness .09mm lam 8” airspace between glass Framing inside glasses lined with acoustic foam Silica packets placed inside for moisture control Butyl Flashing Tape lines window frame where glass meets wood Glass meets at corner with mitered edges, sealed with clear silicone Website reference- http://www.johnlsayers.com/phpBB2/viewt ... c&start=15 See Figures 1 & 2 for construction details Walls Existing concrete block foundation supports double stud wall Double stud wall, 2x4 construction, 16” spacing Where possible, exterior wall remains intact Insulated with R-13 or better UltraTouch Insulation http://www.ultratouch.net/ Walls are 5/8” Gypsum board sandwich with Green Glue and screws All bottom plates have Flexible Sealant or tape where meeting floor Bottom plates treated with Timbor treatment for code Standard pressure treated “green” lumber is poisonous in a sealed room Sodium Borate solution does not off gas arsenic like standard treated lumber See Figures 3, 4, 5, 6, & 7 for construction details Exterior Windows Windows need not open, simplifying construction and reducing cost Total of 3 Windows in locations of existing Windows (NOT as in sketch-up) Double laminated glass with 6” air gap Exterior panel- Laminated glass 5/8” thinkness with .09mm lam Interior panel- Laminated glass 1/2” thickness .09mm lam See Figure 1 & 2 for details on construction Ceiling/Soffit Soffit extends ceiling from existing closet space into large room Ceiling height/soffit - 7’ 6 1/2” Ceiling hung from existing joists with Kinetics ICW hangers http://www.kineticsnoise.com/arch/icw/index.aspx See Figure 8 for construction details Gypsum board sandwich with Green Glue for all ceiling surfaces UltraTouch insulation between joists (best sound dampening and eco-friendly) Floor MDF subfloor on a layer of Green Glue on moisture barrier on concrete Carpeting on MDF with thin carpet pad to attempt to match floor height in main room Subfloor does NOT touch wall bottom plates, isolated with Flexible Sealant Doors Recommend a solid core exterior door hung on each wall for double doors Doors right side hinged Doors are pre-hung 32”x80” doors Bottom seals with Acoustical Door Seal and Saddle 
-http://www.acousticalsolutions.com/products/door_seals/index.asp Door interior surfaces (facing toward middle of wall) covered with decorative acoustic panels constructed with 1” Fiberglass and cloth
 HVAC (details TBD by HVAC specialist) Air handler and A/C compressor mounted on isolation pads Acoustically isolated output and input ductwork using flexible duct routed back and forth inside soffit Return registers for booth and main room Output registers for booth, machine room, and main room

I guess this means I did a good job? I hope I didn't do anything wrong! Did I post this in the wrong area?

Start resizing them pix, it's mentioned in one of them stickies. So, please (re)read those. It'll spice up your live.. if that's what turns you on. :p

Thanks for the tips! I think I'm up to code now.

Yes, that's more like it mr. Gun. Welcome. Haven't really read all the text, just a quick look. the pic doesn't reveal too much since the perspective view. Why don't you, atleast, add a floorplan (topview).

From a rookie point of view; even though the lengths of your walls are not that large I guess one idea could be to implement staggered studs in the walls surrounding your booth. Otherwise it might prove tricky to attach drywall in the appropriate manner.

My biggest concern are helicopters penetrating the booth.

This sounds really scary, for multiple reasons.

The room has a concrete floor with an existing thin vinyl flooring glued down. Should this be removed?

Once again, since I am not an experienced builder my only comment would be in the form of another question. - "What level of isolation would you like to achieve?" /Gash

Once again, since I am not an experienced builder my only comment would be in the form of another question. - "What level of isolation would you like to achieve?"

That is basically the most important question, one I find rarely asked in this forum. There's the established idea that you need soundproof. It is correct and you probably need. The question after is how much soundproof do you really need and what are you trying to achieve. Helicopters like airplanes make a lot of noise. But the perceived noise depends on the distance to the listener. I can say that on several acoustical measurements I did on the countryside, regarding environmental acoustics, dogs at 100 m had an higher SPL at my sound level meter than airplanes, since they were quite high in the skies.

I think a reduction of 40 db from 60-200 Hz and better would be great. I know the lower the frequency the more difficult to reduce.

soundgun wrote:

I think a reduction of 40 db from 60-200 Hz and better would be great. I know the lower the frequency the more difficult to reduce.

Off hand I know of no wall in a feasible for home construction design that has 40 dB of TL. As an example of a wall does is two wythes of 90 mm concrete block with insulation in the gap. Andre

"Standard pressure treated “green” lumber is poisonous in a sealed room " /quote Only if it is on fire.... edit: "Existing concrete block foundation supports double stud wall" /quote 3 leaf wall system, but you are aware of this yes? As for the vinyl on your floor, leave it or remove it, doesn't make you any difference. edit1: "MDF subfloor on a layer of Green Glue on moisture barrier on concrete " /quote How are you going to secure the MDF to the moisture barrier to the existing concrete floor? If you are anticipating a moisture issue...why MDF?

Thanks for your contribution, xSpace! My drawing omits the fact that the concrete block foundation wall is only about 2 feet high, as this space is not below ground level. One row of studs and bottom plate will rest on the concrete wall, the other will go to the floor. Therefore, it's not really a 3 leaf system. As for the floor, what would you suggest as an alternative method? George

"Existing concrete block foundation supports double stud wall Double stud wall, 2x4 construction, 16” spacing Where possible, exterior wall remains intact " /quote You have this or you are building this? If you have an existing framed wall that has an exterior veneer and also has rock or some kind of finish veneer on the interior...that will be a two leaf wall. And if you add another wall with another layer of veneer, 3. A block or concrete wall is only one leaf by itself. I guess I'm having a little lack of focus on what is and what is yet to be built. "As for the floor, what would you suggest as an alternative method? " /quote An alternative would be to fasten this down in a secure manner :)

xSpace: There is no existing wall, only an existing foundation/retaining wall which falls on the East and North walls of the studio and stands only 2 1/2' high. Therefore, the outer wall will stand on the solid concrete retaining wall and the inner wall will rest on the concrete floor. My Sketchup skills aren't too great or i would have figured out a way to represent that in my drawing. I hope that clarifies things. We start building next week, and I will try to keep this post updated with our progress and results.

So glad to see the website is back and kickin'! I was afraid that no sooner did I find the ultimate studio building reference and information site, it vaporized. I have some updates on the build, including images to share of the progress. It's been one heck of a learning experience. Retrofitting an iso room into an existing (old and funky) structure under a tight budget is not an easy task. I am working with a Contractor and construction crew inexperienced in studio building, but with a good deal of hand-holding they seem to be getting it. Challenges that have arisen include: 1- How to pass cabling through the booth into a room on the other side of a bathroom between the two spaces without access to the ceiling above the bathroom, that is large enough to accomodate bundles of cable pre-terminated with DB25 connectors. 2- Passing the HVAC output through the floating ceiling while maintaining airborne and structural isolation. 3- Concerned the exterior walls will be adequately quieted, considering the owner had no interest in redoing the exterior of the structure with new paneling. 4- Recommendations for a subfloor welcome. The current floor is a less than smooth mixture of two different linoleums in various states of disrepair over concrete. Can we just do a smoothing layer of sealant then put down some 3/4" OSB, then carpet padding? Would a layer Greenglue be ineffective between the floor and OSB? What other material would you recommend? BEFORE DEMOLITION FRAMING COMPLETE ULTRATOUCH INSULATION IS IN GYPSUM/GREENGLUE GOES UP

It's hard to tell from those photos, but to me it looks like your inner leaf ceiling framing is attached to your outer leaf roof framing? If so, then you have a major problem. I hope it's just an optical illusion caused by the camera angles... - Stuart -

That is a very good observation. The soffit was a major problem since this new room essentially spans two rooms constructed at two different times. The framers came up with it, and I had a strong feeling it would be a problem. The workaround we are attempting is to have the large store front double window system decoupled from the Inner leaf ceiling framing by a 1/4" gap, which will be filled with caulk. The ceiling is floating on ICW hangers, and the inner wall leaf will extend higher than the ceiling, but not touch the fixed ceiling joists which the ICW hangers attach to.

That's what I figured. Whatever you do to fix it, you need to be absolutely certain that no part of the framing of the inner leaf has any contact at all with the outer leaf. Not even one single nail or screw that got driven too far and touches the other leaf. That's all you need in order to negate all of the hard work that you put into the rest of it. They must be totally separate, isolated, independent structures, all around, all four walls and the ceiling too, and absolutely hermetically sealed. The concept of a "room within a room" is just that: no connection between the two. If there is any connection at all, then the cost and effort of building two walls is just a waste of time and money. Posting more photos of the construction details would be useful for the experts here to be able to see if there are problems, and to suggest how they can be fixed.

Soundman2020 wrote:

That's what I figured. Whatever you do to fix it, you need to be absolutely certain that no part of the framing of the inner leaf has any contact at all with the outer leaf.

So what do you recommend he do with the concrete floor that everything is sitting on? Or the existing walls that flank at the corners?

So what do you recommend he do with the concrete floor that everything is sitting on?

Gee, I dunno! How about just leaving it there, and letting it be a very large mass damped by the ground underneath, so it isn't much of a problem? After all, that does seem to be the general consensus of the experts around here. Unless you think he should cut the slab?

Or the existing walls that flank at the corners?

Well, that kinda was the point I was getting at, ya know! Perhaps you missed the posts where I questioned that, and he agree that it is a problem? Personally, I think that detailed photos and 3D models would help to understand the issue better before offering advice on how to fix it, but if you have a solution to offer without bothering to look at the situation, then I'd like to hear it.

It only means that some things we have to live with. If the build develops that way, then you live with the limitations, if they can not be corrected.

Hello gentlemen: It's been a year, but I wanted to see the fruits of our labor. Also for your enjoyment, check out this audio clip. Thanks again for all of your help!