Absorbent Open Ceiling

I've thought it over a bit and crunched some numbers and I've come to the conclusion that I'm not going to do a hard ceiling. Loss of space, achieving a good room ratio, and available finances have determined that I stick to my original plan of creating a better sounding room and leave it at that. That being said, should I completely throw in the towel on trying to achieve any transmission loss between my neighbors and upstairs? I'm still going to put up new walls, if only for cosmetic reasons. So what would be worth doing during the build that might help isolate along the way - even if it's only a little bit? Should I still bother spacing inner frames away from outer walls? Or decoupling where the walls meet overhead joists like you described in your sketch? Or is all hope lost without an overhead MSM ceiling? On the flipside of that question, Is there anything I should incorporate into the new wall build that would contribute to a better sounding room? Room ratios and post-build absorption/diffusion treatment aside. Drywall "X" vs Drywall "Z" for example. Wood framing vs Light steel? Any tidbits of helpful information I could relay to my builder buddy are welcome. With ideal isolation out of the picture now, I at least want to achieve my original goal of making my room more accurate to create mixes that travel better... as well as "pretty" up the room a lil bit :wink: Can't wait to get rid of the wood panel walls :D Oh Happy Day! Thanks for all your help Glenn - I owe you a couple drinks by now

cheers! I'm sometimes down Philly way (in San Fran today)

Give a heads up next time you're in town - Drinks are on me!

Is it worth trying to beef up the underside of the floors above with 5/8 drywall? - without a hard MSM style ceiling of course. Looking for ways to lower noise transmission to / from family room above studio. Impact noise isn't a big issue, but would like to quiet down the TV noise. I know the reduction won't be as good as with a proper MSM, but any improvement is welcome. Thought this would be an easy way to gain some reduction, but after removing old ceiling grid I can see now that the task will not be as easy as hoped for. Cross bracing needs to be removed/replaced. And theres lots of nails sticking through the bottom of subfloor above. Not sure how to deal with these if I were to beef up. What are your thoughts - To beef, or not to beef? Just about done with the demo. Drywall coming next week : ) I'll post up some pics of the horrors being hidden behind that wood paneling I couldn't wait to get rid of. Lets just say I've got a couple days of concrete wall repair before I start putting up any drywall. Oh well - that gives me a couple more days to soak up as much helpful information as I can here. Please - Keep it coming : )

i would beef it up with layers of 5/8". Rod has a detailed explanation in the book but basically you're going to add 3x layers of 5/8" drywall and support it with cleats and seal. use some blue style foam insulation if you have nails coming through then add the drywall. caulk is your friend. then using the RC-2, add at least 2x 5/8" drywall off the joists. add any necessary framing around the beam. not as good as either suspended or fully decoupled but will be better than not using it.

gullfo wrote:

then using the RC-2, add at least 2x 5/8" drywall off the joists.

You lost me here. This is an absorbent fabric covered ceiling. The only drywall would be between the joists on the underside of the floorboards which would be supported with cleats. Where would RC come into play?

sorry, No RC... i keep forgetting your going with an open ceiling and skipping any significant isolation.

ok - so everything else still applies though, right? Glad you mentioned about the foam board because I do have lots of nail points coming through the floor boards that I was wondering how to deal with. The other thing I wasn't sure how to deal with is the cross-bracing in the middle of the ceiling. I would have to remove this to install the drywall but I'm not sure I have the carpentry skills to make new bracing. Is there a more modern alternative to wood cross-bracing that might be easier to install? Without the beveled wood cuts and what not.

there are several approaches to re-installing the bracing - re-do the cross bracing - a) reuse the same lumber if you carefully removed it, b) install 2x8 or larger solid blocking, c) use steel cross bracing members (check codes). the steel cross bracing usually can only be applied when you have the subfloor off since it's really a set of straps.

gullfo wrote:

use some blue style foam insulation if you have nails coming through then add the drywall.

Was out looking at foam board today at home depot. Your talking about a styrofoam type panel - correct? Saw some pink owens corning insulating foam boards as well as sheets of plain white poly styrofoam. Is there any difference for my purposes - A backer for layers of gypsum board? Also - how do I attach the foam? I'm guessing I'd glue the foam board to subfloor - Then press drywall snugly against it and support with cleats. Should I glue drywall to foam boards as well before cleating (if that's a word)? And what kind of caulk at foam/drywall and joist edge - acoustical caulk or otherwise?

you should be able to simply jam the insulation onto the nails and/or make it a snug fit between the joists.

Buy the "pink" boards. The "white" boards turn into little white "beads" and make a HUGE mess. Tom

I am in the same process of beefing up between the joist ... I have lots of nails poking through ... I used a product called 'FORMULAR R-50' by Corning. I had to use the 1" thick boards. It comes as a 4'x8' piece. I used a hand jig saw to cut them into 14" strips. That worked nice. I just jammed the pieces into the nails above and they're holding good. Drywall goes in next. I couldn't find what I wanted at Home Depot nor Lowe's ... when to a lumber company for the material. Hope that helps you !

DeeringAmps wrote:

I have lots of nails poking through ... I used a product called 'FORMULAR R-50' by Corning

Thanks - I found this product available near me. I'm wondering if these foam boards would help to lessen the TV noise transfer from the room above with my open ceiling configuration. More than drywall and insulation batts alone? After looking at the overhead floorboards a little more, there's only a small area where the nails protrude significantly. Most of them don't come through more than a mm or so. So unless these foam boards might help to cut down the TV noise transfer from above, I may only use them where necessary and just do drywall without the extra foam board everywhere else.

it's insulation. if it seals something not sealed or absorbs some of the frequencies there will be some attenuation but i would not expect any significant isolation value.

Ok - will prob go with just sheetrock then where I can. Do I need to do fill in the spaces between the subfloor boards before putting sheetrock in place, or can I leave them be? Also - should the caulk around the edges be acoustical caulk or the latex/silicone stuff? Thanks.

seal everything you can with caulk - a long lasting non-hardening caulk will suffice. if you don't have nails protruding you can go right in with the drywall, otherwise some flat panel insulation (blueboard, FORMULAR, etc) should be used to cover the nails.

gullfo wrote:

if you don't have nails protruding you can go right in with the drywall, otherwise some flat panel insulation (blueboard, FORMULAR, etc) should be used to cover the nails.

What if the nails only protrude a mm or 2 (as is the case for most of my ceiling)? Is foam panel still necessary? Or would that 1-2 mm airgap hurt my TL between me and room above? That is if I had the drywall pressed against the 1-2mm protruding nail tips. Need to cut costs wherever I can unfortunately. *Reminder - ceiling will be open fabric covered ; ) Speaking of which... What is a good alternative to fiberglass / mineral wool for filling between the ceiling joists. I know the American Lung Assn. says the stuff is safe but I would feel more comfortable and breathe a little easier just knowing that I don't have once-believed carcinogenic fibers falling from the sky. The easier to install, the better, but it can't droop down into the fabric. Again, this is for a small-ish mix room with a reflective floor and low ceilings (hence the open-ness)

if you can achieve good contact with the upper floor, then you could skip the foam board but i'd press the drywall onto the nails bas much as possible. as for insulation, depending on the reports you read, the cotton insulation is worse for your lungs... you could use micromesh cloth to cover it, or plastic sheeting.

Sorry if this is a silly question, but which side of the drywall should I be pressing into the nails?

the paper side...

ok - wasn't sure if it was ok to penetrate through the paper. thanks.

In reference to using the thermal sheathing panels up against the upper floor, if there is even the slightest protrusion of nails into the, or rather, that have penetrated through the upper floor sheathing, you should use the thermal sheathing. If you take and jamb sheetrock against the nails, you run the risk of pushing the nail back up into the above flooring. That can produce holes in vinyl, bumps in vct, cracks in ceramic tile and squeaks in wood flooring. It is one of those areas that you do not want to start tightening the money purse since there are so many other areas of little to no consequence further down the road which would be more suited to the restriction.

thanks Brien, given the nails are 2mm (sounds like the nail points) do you think maybe just some caulk on the back of drywall would solve it?