John Sayers' Recording Studio Design Forum Archive

This forum is great, I've found answers to most of my questions by searching, but I've got a question that I just can't think of how to search on.

I'm building a studio in my garage. My main goal is to keep the neighbors from complaining by soundproofing as best as I can. I'm doing the "room inside a room" approach. The new walls will be: stud frame with insulation, then 2 sheets of 5/8" drywall, properly decoupled using laminating screws and joint compound for the second layer. I'm using 2 sheets of 5/8 instead of a layer of 5/8 and a layer of 1/2, because I read here in a post somewhere that the two layers of thicker material beats two layers of different materials for Low frequency isolation, and I'm mostly interested in isolating the drums. So, here's my question. How detrimental would it be to mount guitar hangers (several) to the studs, or for that matter anything, like shelves, etc. My walls are just 2x4, not staggered studs, not resilient channel, (well, technically i haven't built them all yet, but this is the plan). I realize that putting a screw through both sheets of drywall would effectively decouple the two layers and make them act as one, but since they are the same thickness anyways, will this make much of a difference. Thanks in advance for any comments. I will provide other information if necessary.

On your foundation walls , probably not a good idea, however if you have treatment walls in this room (which are not part of your isolation (2 leaf room in a room) scheme then that woule be just fine.

Bryan Giles

2 things to think about...

First- if you're building a true room-within-a-room system here, don't worry about decoupling the drywall from the studs. The room-within-a-room design puts the decoupling part right into the structure, so you can do whatever you need to while hanging the drywall.

Second- if you have the floor space available to space the inner walls away from the outer walls, you might be better served using John's inside-out wall contruction. This is essentially building the wall on the ground, drywalling the BACK of the wall, and tipping it up so that the drywall is between the studs and the outer wall. Your studs will be facing the inside of the rehearsal space; you can use the spaces between the studs for room treatment later on if you decide you need to work on the acoustics (for a practice studio involving drums I'm sure you will want to eventually) and you can hang whatever you want off the studs without affecting the sound isolation at all.

BTW if you're doing a real room-within-a-room system, don't forget to build the ceiling off the new inner walls... the room has to have a cap or the system is useless...

Good luck!

Kase
www.minemusic.net

Good advice from Giles and Kase - since the posts on laminating screws, I've found out from others with direct experience that it's NOT a good idea to rely on laminating screws/glue - possibly OK on walls, but not necessary (therefore not worth the risk) when using separate framed walls (meaning wallboard only on one side of the frame) - your inside insulation will take care of 99% of flanking problems due to fasteners, and adding guitar hangers shouldn't be a problem.

After re-reading your first post, I'm not clear if you mean you will be putting up a second frame inside existing frame, or adding your materials to the existing frame - that will make a HUUUUGE difference, so please clarify BEFORE you go ahead on this... Steve

Thanks for the replies guys.

Yes, I'm building the new walls about 3 inches apart from the existing walls.

So, from what I'm seeing I shouldn't worry about laminating screws and joint compound, and just screw both layers of drywall directly to the studs, and it should be OK to be put the hangers directly on the studs. Is this correct?

If that is the case and these new walls ar enot for proofing but acoustical correction, you are free to hang whatever you feel.

My easy read version answer. LOL

Bryan Giles

I'm confused.

Ok, here's what i've got.

I started with a 17x22 garage with chipboard walls. First I framed in the garage door and put aluminum siding on the outside to match the rest of the house. Next, I've pulled off all the cheap chipboard to leave just outside siding, 2x6 framing and insulation. Now I'm going to step off about 3-4" from these walls and make new 2x4 framed walls seperate from the old walls. I will fill new walls with insulation also, then two layers of 5/8" drywall. These walls are my attempt at soundproofing, haven't gotten to acoustic treatment yet. So..should I secure one layer of drywall to the new wall studs with screws, then secure the next layer of drywall to the first layer with the Type-G screws and joint compound, or from what I think you're saying that would be a waste. Just to clear it up, these walls will not be touching the original garage walls and these new walls are for sound proofing, so is it a bad idea to try to put these guitar hangers up?

thanks guys for your prompt replies, I'm not used to this fast of a response time from most forums

First I framed in the garage door and put aluminum siding on the outside to match the rest of the house. Next, I've pulled off all the cheap chipboard to leave just outside siding, 2x6 framing and insulation.

Interesting. So there used to be chip-board wall paneling on the inside of the existing walls, but it's gone now? Not a big deal- just means you have to put something up in it's place- which I was about to recommend anyway.

To get a 2-leaf wall system with what you're planning, you should add a layer or 2 of drywall to the inside of the existing walls, where that chip-board used to be. With the chip-board gone you can run the drywall right over the framing where the door used to be, and seal it off nicely. If you put 2 layers of 5/8" up there, then put up new inside walls with 2 layers of drywall, you'll be able to make all kinds of noise in there.

At that point adding more isolation to the walls will be un-important compared to making sure the doors are well-built and sealed properly.

Hope this helps.

Kase
www.minemusic.net

OK, now we're getting somewhere -

Problem #1 - the aluminum siding on the outside of your outer frame doesn't have enough mass to work well as half of a double-leaf sound barrier - that leaf needs more beef in order to do much. Maybe you could remove the insulation and cut 2 layers of OSB to fit between each pair of studs, placing the OSB up against the vapor barrier and fastening with cleats, then caulking - this would give a pretty solid outer leaf for a 2-leaf wall system.

The heavier you can build your outer walls, the lighter the inner wall can be - this is a good way to go, because it makes your inner walls act like bass traps so you'll need less trapping in order to make the room sound OK.

As to multi layers of sheet rock on a frame - you can cut the # of fasteners in half for all but the final layer of rock, which should have standard 12" spacing in the fields and 6" spacing around the edge of each sheet. Place spacers at the bottom of the frame that are 1/4" thick, set each sheet of wallboard on the spacers and fasten to the frame, being sure to offset joints from layer to layer to avoid cracks that could pass sound through the wall. After each layer, caulk thoroughly with acoustic rated caulk - with the exception of the caulking around the perimeter, these are standard drywall techniques.

Without two solid leaves in your wall, you won't get very good sound isolation - let me know if what I suggested isn't clear to you.

As far as the hangers go, if you fasten them through the wallboard into the studs of the inner wall frame and insulate that frame, you won't see much change in sound isolation. The insulation helps keep fastener flanking noise from becoming noticeable.

What you may find, however, is that your hanging guitars will resonate with the sound in the room and mess up otherwise good recordings - not much you could do about that other than take down the offending instrument when recording (or mixing) ... Steve

wow, thanks guys, I hadn't even thought about my outside leaf not being thick enough, I will definitely follow these suggestions, for the cheap price of OSB i'd be a fool not to. Just one question, about securing the osb to the vapor barrier board, what are cleats, or what do they look like? Also, just to clear up, i SHOULD still use the laminating screws/joint compound approach to hanging the second layer of drywall on my new wall? Thanks guys, I've learned a lot already.

Cleats are just small dimension pieces of wood, like 1" x 1" lengths ripped from larger lumber. They are screwed or nailed into larger framing (like studs) to hold the inserted extra layers (in each stud cavity) up against the outer siding. I'm almost late for work, but I'll find or draw you a pic later.

No, forget laminating screws and glue - just put the first inner layer on with screws further apart (saves screws, lessens flanking through the screws) then the final layer at right angles (rotate the sheets the other way) and offset any joints so the do NOT line up. use the closer spacing on the last layer for strength and stiffness... Steve

You are saying that you screw both layers of drywall to the studs ? Also I am getting confused about the 2 leaf system , I have read 2 or 3 different ways . Is it possible to give a diagram of what you mean ? Also could you give your opinion on this stuff.
http://www.cascades.com/pdf/brochure_sonopan_en.pdf .
Jim

Packinshed, there are a couple of drawings on this page showing isolation of leaves (a leaf is ALL the layers of mass on ONE side of a stud frame - if there is no air gap, it's all one leaf. )

http://www.johnlsayers.com/phpBB2/viewt ... c&start=45

Those pix were done showing Resilient Channel - if separate frames are used, no RC is needed because the frames are already isolated from each other by the space between them.

the 2-leaf system means having one center of mass (like 2-3 layers of drywall on the same side of a wall frame) then an air space (usually with insulation ) followed by another center of mass, which can either be mounted on RC or staggered studs or completely separate stud frames, depending on the amount of isolation required.

For a double framed 2-leaf wall - put up two separate stud frames (sequence is depending on your particular situation, this is just for what goes where, NOT when...)

Then, mount a layer of wallboard on the inside of the inner frame, and another on the outside of the outer frame, after first placing insulation batts between studs on both frames. The insulation should press lightly back against the panels when they go on the studs. Use half as many screws to mount these first layers as normal - that would be like screws every 16" along the edges of panels, and every 24" through the inside area of the panels. Be sure and use 1/4" spacers along the floor and set the panels on the spacers before fastening - once each layer is fastened, pull out the spacers and seal with acoustic rated caulk - mud and tape any seams, especially tapered ones.

Set new spacers for the next layer, place the panels with the long dimension at 90 degrees to the first layer, fasten with screws at normal spacing (only if this will be the LAST layer) - normal spacing is 8" edge, 12" in field (not edges of panels)

The best thing you could do for yourself is download the USG manual, linked here in the "stickies" section - the above info is from page 109 of that manual.

Sonopan is another distraction from building solid soundproof walls IMO - unless you can get it cheaper than sheet rock, I wouldn't bother. I've checked out their claims before, and always come out with as good or better performance using standard gypboard/stud partitions... Steve

Thanks . THat very much clears things up and is what I thought but had to be sure .
Thanks again
Jim