Also, is it necessary to use the standard amount of screws on the first layer of drywall since the second layer will be screwing through it as well? You figure the second layer will have 45-50 screws through it or so, can you get away with half that amount for the first layer?
BIG mentioned this idea a few posts back for the subfloor work, not sure if this is a good idea for the ceiling itself.
As you say, the key to the screws is how many are in the finished layer. I expect most installers go light on the first layer of screws. Sink all screws into the channel
Sorry, my project is sound proofing project from upstairs neighbors. From what I can tell most of the sound is coming in through the ceiling and not down through the walls. I mean if I put my ear up to the wall you can hear some flanking traveling down the wall, but I figure once the subfloor is treated that flanking will be reduced even more and any noise from the walls will be DOA once it hits the air.
ive been trying to read up on soundproofing and I thought the idea was to leave a gap around the perimeter so the walls and ceiling are not coupled,,and then to simply caulk this edge. Now it seems like Ted said to interlock the two....Im really confused now.....
This is my first post/questions, so please bear with me. I have obviously read many threads and benefitted from all of you for my complete basement build-out with a dedicated home theater. I will likely follow with a thread of my build, borrowing much wisdom gained here. I am at post-framing, post-wiring mode and now focused on insulation and soundproofing.
In my HT, 3-walls face the concrete foundation with earth (basement is below grade). The 4th wall connects to the rest of the basement and contains a heat pump system (HVAC). I have framed that within a small room to also hold my AV equipment, so I will ensure soundproofing that connection to the rest of the basement.
I have already installed an in-ceiling drop-down projector lift (Draper Aero-25) and in-ceiling drop-down screen (Da-Lite); they are hardwired and tested fine with IR remotes I will ultimately control simultaneously with lighting and AV equipment. I am building a stage to also house my drum set and I am mounting motorized drapes behind the screen that will close behind that and the Center & Subwoofer mounted in the stage front (of course I will construct the stage per many threads here with sand, etc.). The drapes will also be integrated into the master control.
Above this room is our sunroom with a hardwood floor, a subfloor and I-beam joists, running the long length of the room (front to back of house). The sunroom is not used that much. The heat pump/HVAC is dedicated to that room and the HT.
I framed a barrel-vault ceiling in the HT, which at highest point is 9'. Along with 1/16" MLV and R-19 Johns Manville insulation, I was planning to install GG+3/8" drywall + GG+3/8" drywall, because I need flexibility to cover the barrel vault ceiling. I am obviously trying to save money here. Questions:
1) I know there may be better options (e.g. decoupling), but is that ceiling covering adequate, in your opinion(s)?
2) Do you think I need to match the same layering on the 3-stud/concrete foundation walls to "sonically balance" the room, or can I just get by with the R-19 + 1/2" drywall?
3) Should I add a gap between walls and ceiling and add acoustic caulk?
On the 4th connecting basement and perimeter HVAC wall, I was planning to use the MLV + GG +1/2" drywall + GG + 1/2" drywall. Sorry to be so wordy and if I am repeating questions from before, I just don't have the time right now to research hundreds of threads.
Thanks so much!
First, I am honored to hear from the great "Oracle" and appreciate your prompt response. You don't miss a beat....
Short answer is yes, in a manner of speaking. I fabricated plywood enclosures after the fact (ends and bottoms with the open top being the subfloor above). The screen needs clearance above if it ever has to be removed. I can easily remove the screwed-in bottoms for full access to devices. I had planned to pull some MLV over the tops of the devices and secure that to the subfloor above (about 3-4" clearance between devices and subfloor). Then cram as much R-19 as I could fit without compromising operation. These two cavities would likely be the least sealed areas, as compared with the GG/Drywall layers. I will place R-19 on the outside of the enclosures, along with all the other R-19 I will install between the ceiling joists.
Following your logic, in hindsight, I would have installed soundproofed enclosures and then mount the devices. With so little clearance and my desire to move the electrician along, I proceeded the way I did. I'm not sure I would have had enough space for sealed, soundproof backer boxes, as the average clearance between joists is about 16.5 inches. In other words, the width of the joist cavities is greater than the I-beam entry points, so I had to build them in-place.
When I install drywall, I will have to make cut-outs for the lift and screen to descend/ascend. The middle drywall cut-out for the projector lift will mount to its bottom (that I fabricated with 1/4" plywood)--projector will rest on it; it will be flush with the rest of the ceiling when closed. Two, side cut-out panels will be fixed--they'll allow room to work when removed. The motorized drapes are behind the screen and will share the screen's drywall cut-out (a long, wide slit). I am mounting hexagonal connecting bolts into insert nuts imbedded through the drywall into the barrel vault arches. This will enable easy removal of all cut-out panels and then enclosure bottoms if I ever have to access the Projector Lift and/or Screen & Drapery Assemblies.
...okay, I know I have to learn to write much less...sorry again.
Fact 1/2 lightweight weighs 39 lbs a sheet. 5/8 heavy weighs 70 a sheet. Which do you think is going to contain the sub-woofer rumble?
Swiss Cheese update: I'm quite familiar with the wisdom someone said--There always seems to be enough time to keep fixing something, just never enough time to do it right (the first time)....
Having removed equipment and ripped out previous mounts, I am now building sealed MDF enclosures with 2" thick Sonex-polyurethane panels, to mount devices within. With ceiling cavities exposed, I will secure MLV barrier, then blocking (to create a gap from upper the subfloor and serve as top mounts). I will fill the gap with R-19 (leaving blocking exposed). Then I will add GG to blocking, secure MDF, GG and MDF (the blocking will prevent subfloor penetration of screws). Finally, I will run two lengthwise beads of acoustical caulk on the tops of enclosures, securing them to the bottom layer of MDF. I will use rubber washers between my lower access panels and the enclosures for future access. Hopefully, even Gamma rays won't get through.
I'm so glad I have a drywall hoist...increasing my sets of push-ups so I can handle all that 5/8" drywall soon. On second thought, I just may outsource that part!
Gosh, Jeff...I almost lament that you were right, but with over 19,000 posts and a livelihood, you must know what you're doing....