Rip out existing insulation?

Hello All, My first post, but I've been reading for a long time. This forum has been an invaluable resource for browsing and collecting information. But now I have a question that I can't find the answer to in any previous posts! First some background: I'm building an 18x13 room in my garage for recording mostly acoustic blues, with small ensembles that will include drums, bass, vocals and horns. I'm using the garage's existing concrete floor, which is a separate slab. I will build a semi-independent ceiling. I am planning two layers of drywall greenglued on the inside of the room, and just insulation on the outside. I am currently in the process of sealing off the garage door with a 2x4 frame, 5/8 drywall on the other side and mineral fiber in between. (The garage door will not be used.) This is a residential neighborhood and my garage is in the front within about 15 feet of the sidewalk. A neighbor on one side is about 20 feet from the garage. The garage already has 1/2" drywall all the way around. From this forum and Rod Gervais' book I have learned that contrary to logic, it will actually be better for me to rip out the existing drywall and insulate between the studs for the room within a room to be effective. So I hacked into the existing drywall today and found that there is already fiberglass insulation in the walls. But it's a weird kind, with an aluminum foil type layer in the front and a vinyl backer sandwiched around the fiberglass. I think it's this: http://www.insulation4less.com/highr_FfgV.asp Now my question: Would I be better off not building the room within a room and simply green gluing another layer of drywall to the existing drywall? Or, does this foil-fiberglass-vinyl insulation create a bad mulitple leaf situation, and so therefore should be completely removed? Sign me, Flummoxed

Hai and welcome to this forum :) That's thermal insulation, which you can remove. Or if the insulation is flush against the outer wall, you can leave it in place. It'll do nothing much with sound absorption. From your text I can't really make out your current set up; how are ye walls setup for now? What about your ceiling?

Thank you for identifying it. I'd never seen it before. I guess you can tell I've never worked in the building trades! So even though this thermal insulation has three layers, I could leave it in place and put more insulation on top of it? The layers (foil-fiberglasss-vinyl) are bonded together. My current walls: 2x4 frame with one sheet of 1/2" drywall. I don't know yet what's behind the thermal insulation because it's stapled to the studs. THe outside of the house is wood siding. The ceiling: 8 1/2" tall, also covered with 1/2" drywall and the same thermal insulation is in the attic along with blow in batting.

I think you run the risk of multiple leaves if you leave it in place. You also eliminate the option of beefing up your outer leaf. I'd love to see some drawings and photos of your project. You have a big job ahead of you, and the more visuals and details you can provide, the more we can be of help. Have you reviewed all the Portland project threads?

Lost Studios new construction build Portland Oregon piano teaching/recording studio - construction questions Lost Studios new construction build Portland Oregon

You might try contacting these guys to see if you can visit their places. I know when I was just starting out, getting together with fellow semi-local DIY studio builders was really helpful to me. --Keith :mrgreen:

Thanks Keith! I've read your amazing thread several times through -- just referred to it again yesterday. Yes, I do have a big job ahead of me, but it helps a lot to have the wisdom of those who've gone before. This is actually my second home studio build. I went through this in the late 90s, building a room within a room with a floating floor. I just moved, and of course a garage with studio potential was one of my requirements. So much has changed since I built the first studio, not just materials but access to information and other people's experiences. I have accepted the fact that I'll have to remove all the existing insulation in my existing walls. I'll probably replace it with pink fiberglass (R-13, R-?) with drywall strips underneath. Then I'll build the room within the room, with two layers of 5/8 drywall on the inside and mineral fiber on the outside. Just got back from Home Depot where I bought a Dremel attachment for $29.95 to cut the drywall. It's called the XBR multisaw. Works like a charm, and is much easier than the box cutter knife I was using before :) Appreciate the Portland links, too!

Or, does this foil-fiberglass-vinyl insulation create a bad mulitple leaf situation, and so therefore should be completely removed?

How does insulation in an exterior wall produce a bad situation? Exterior walls need to be insulated, especially at home:) I can see your concern coming up against a variable that you are not familier with but proper insulation, in any form, is what it is. Brien