Author Topic: Soundproofing basement suite ceiling  (Read 10404 times)

brian_bc

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Soundproofing basement suite ceiling
« on: May 28, 2013, 03:57:07 PM »
Hey, my upstairs renters are quite noisy and I can hear conversations they are having. I have pulled down the ceiling with was 5/8" drywall and some pink insulation. It was suggested to me that I put in Roxul Safe and Sound in between the joists and then screw soundboard to the joists, then put in a resilient channel with 5/8" drywall under that. Would be be better if I put the resilient channel on the joists then the soundboard and the drywall directly on the soundboard?

Randy S

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Re: Soundproofing basement suite ceiling
« Reply #1 on: May 28, 2013, 04:24:35 PM »
Yes, the resilient channel goes to the joist first. Dont waste your money on sound board, the cavity is already insulated. Use double 5/8" drywall with green glue if you can afford t. Make sure they leave a 1/4" gap around the entire perimeter to be filled with acoustical caulk. Do not mud and tape the perimeter.
http://www.supersoundproofingsales.com/prodinfo.asp?number=09--GREENC

http://www.supersoundproofingsales.com/prodinfo.asp?number=09-42745-S

http://www.supersoundproofingsales.com/prodinfo.asp?number=09-RC2D
Randy Sieg

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888-942-7723
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brian_bc

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Re: Soundproofing basement suite ceiling
« Reply #2 on: May 28, 2013, 05:32:16 PM »
If I can't afford the green glue is there any benefit to just doubling up the drywall without it?

The acoustical caulk around the edges will that give a finished look or will it look like I have black goo coming out from the perimeter of the ceiling?

Randy S

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Re: Soundproofing basement suite ceiling
« Reply #3 on: May 28, 2013, 06:26:06 PM »
just doubling the drywall will help. And the acoustical caulk is white and will finish similar to your bathroom caulking.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

johnbergstromslc

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Re: Soundproofing basement suite ceiling
« Reply #4 on: May 29, 2013, 09:44:33 PM »
Hey, my upstairs renters are quite noisy and I can hear conversations they are having. I have pulled down the ceiling with was 5/8" drywall and some pink insulation. It was suggested to me that I put in Roxul Safe and Sound in between the joists and then screw soundboard to the joists, then put in a resilient channel with 5/8" drywall under that. Would be be better if I put the resilient channel on the joists then the soundboard and the drywall directly on the soundboard?

Yeah, soundboard will hold drywall on the wall, but using it under ceiling drywall is beyond a bad idea.  Think crashing panels, probably in the middle of the night....

supersoundproofing

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Re: Soundproofing basement suite ceiling
« Reply #5 on: June 17, 2013, 12:34:31 AM »
If I can't afford the green glue is there any benefit to just doubling up the drywall without it?

The acoustical caulk around the edges will that give a finished look or will it look like I have black goo coming out from the perimeter of the ceiling?

Hi Brian,
If you don't want to use Green Glue, you can use strips of the sound Isolation tape instead.  Put it on the face of the studs for the first layer of drywall, then over the second layer where the studs you just covered are.  Be sure to use 5/8" drywall panels for best results.

The acoustical caulk is non hardening but won't "ooze".  See http://www.supersoundproofingsales.com/Tapes/products/23/ for the tape and http://www.supersoundproofingsales.com/SSP-Acoustical-Sound-Sealant-Caulk/productinfo/09%2D42745%2DS/  for the caulk.

It's good to call if there's any question on how to use any of these products or procedures.  Mistakes can be costly and wasteful.  For instance, because you have a double panel thickness of drywall, there's a large gap around the perimeter.  (anyway there should be!).  You must fill that gap, not just "skim" it over  or you'll have a sound leak all around the wall.  That's one reason we sell the large 29 OZ tubes, it will take a lot of material to do it right.  (BTW the right caulk is white).

There's other tips we can give you when you call we don't have the time to go into here.

Best of luck with your project.

BJ
Super Soundproofing Co
www.soundproofing.org

jhbrandt

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Re: Soundproofing basement suite ceiling
« Reply #6 on: June 22, 2013, 03:29:07 PM »
Brian,

Don't forget to use a backer rod with that caulk! This is very important because the caulk will fail if it adheres to more than 2 surfaces.

So do it like this:

Install resilient channel or clips (then hat channel) fill the space with light building insulation, nothing fancy or exotic.. just regular building insulation works best for cavity fill.

Next; attach one layer of 5/8", fire-rated drywall (fire-rated because it is HEAVIER and mass is what you need). Plaster and tape the seams so that it is seals. DO NOT plaster the perimeter, but GAP the drywall away from the walls by about 1/4" to 3/8".

Once the plaster is dry on that first layer, go around the perimeter of the new ceiling gypsum board stuffing 3/8" to 1/2" backer rod into the gap so that it leaves about 1/4" of depth for caulking.

Caulk the perimeter and 'finish' the caulk joint by the manufacturer's recommendations. - This is usually running your finger down the caulk line so that it is smoothed and pressed into all the cracks and crevices and properly seals the joint.
.... here is where you apply the Green Glue if you can afford it.
Next step; apply the SECOND layer of 5/8" drywall... move the sheet over one hat channel and begin so that NO SEAMS are in the same place. Stagger the seams!!

Rinse and repeat the procedure that was done for the FIRST layer of drywall. But for this final layer, you'll want to finish the plastering in the middle of the sheet so that it is nice and smooth looking. DO NOT plaster the corners or edges.. use the caulk as I described above. Once it is painted, you won't notice it unless you do a crappy job. ;)

Cheers!
John

jpayne

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Re: Soundproofing basement suite ceiling
« Reply #7 on: August 03, 2013, 06:32:26 PM »
I am in a similar situation I have a 12x16 basement bedroom in my downstairs which I rent out...the bedroom is right under livable space (tile floor w/80% coverage area rug)...What I hear the recommendation to be is -after the ceiling is taken down seal and places with acoustical caulk...insulation (I think I have some bracing between the joist so I will have to break hear and there)...Insulation (safe & sound...maybe)...MLV(maybe?)....then clips...resilient channel...2 layers of 5/8 drywall with GG in between...2/3 tubs GG each 4/8 sheet...oh forgot...putty pads to put on the back side of and 4" electrical boxes...does that sound right...

Thanks

jhbrandt

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Re: Soundproofing basement suite ceiling
« Reply #8 on: August 04, 2013, 12:31:45 AM »
jpayne,

What you need to do in this situation is to ADD MASS to the floor partition... AND add another decoupled partition to further attenuate sound.

This is done NOT by adding acoustical caulk but GYPSUM BOARD/PLASTERBOARD/DRYWALL (all the same stuff - just different countries). You'll need to 'beef up' the mass of the floor by adding mass. If you double the mass of the floor partition, you will have an increase (average) of 5 dB points to the overall sound transmission loss.

So, carefully remove the bracing (keep it, because you must replace it again), cut strips of 5/8" drywall to fit between the joists. Install the drywall with short screws and caulk the edges. Seal it well. You can put two layers for better STL.

Replace the braces, refill the joists with R-19.

If more STL is needed, add resilient hangers or clips and 2 more layers of 5/8" drywall. When doing so, make a 3/8" gap all around the perimeter of the new ceiling, fill with backer rod and caulk so that the new ceiling 'floats'. You probably won't need Green Glue, unless you are playing drums above the bedroom. ;)

Electrical boxes; just don't put any boxes in the new ceiling - put the electrical boxes ON the ceiling. Caulk the cable entrance hole very well.

Cheers,
John

jpayne

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Re: Soundproofing basement suite ceiling
« Reply #9 on: August 04, 2013, 06:52:35 PM »
Thanks so much...but I am going to have to put electrical boxes in the ceiling...just the 4" ones for 2 lights-the ceiling is already going to drop a few inches with the resiliant channel so I can't make it any lower...I was thinking of using putty pads and acoustical caulk to seal up the boxes?....so you are suggesting that I don't use in MLV....just go with the 5/8 layer of drywall on the under side of the subfloor, using acoustical caulk to seal that...then the insulation-any advantage of using "safe n sound"....clips w/resilient channel and 2 layer of 5/8 drywall....

jhbrandt

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Re: Soundproofing basement suite ceiling
« Reply #10 on: August 05, 2013, 01:52:30 AM »
j,

If you MUST put HUGE holes in your decoupled partition, then you must build a box INSIDE the ceiling to effectively enclose the electrical outlet in the same mass barrier as the new ceiling partition. So, you will need the equivalent mass of 2 layers of 5/8" drywall 'around' the electrical boxes. These small things can/will break your isolation attempt. I've seen it over and over where folks will build a decoupled partition and either cut big holes in it and not seal it well or inadvertently 'couple' the partition to the structure with an electrical box or other bracing - effectively WASTING all they had put into this new, wonderful, decoupled, sound-proofing effort.

You're going to need to get creative here. The electrical boxes need to be secured so that they can support the weight of the lights. This means that they will need to be attached to the Channel. Otherwise, you might as well NOT put any clips and channel if you are going to connect the electrical boxes to the structural floor. (Them Hobbitses is tricksey..aren't they Precious?...)

When you are trying to sound-proof, you need MASS. One step better than mass is a resonant system, as you are attempting above.. a mass-air-mass system. Two decoupled partitions with an air space or spring. That said: the MASS of each partition is ALL that counts. I recommend buying the cheapest mass you can get. Drywall is, of course, the cheapest. You can get MLV if you want, but I think it's a little silly to spend 10 times as much money for the EXACT same effect. MLV definitely has it's place, but it's not Here.  ;)

Wall or Ceiling cavity insulation: Testing has shown that the lightweight fiberglass insulation TRUMPS the higher-density stuff, especially cellulose fiber. Safe-N-Sound is a good wall cavity insulation, but it is a bit pricey. The higher-density insulation is GREAT for acoustic treatment IN the room if you are doing voice, or music, etc. But lucky for most, the regular fiberglass R-13, R-19, etc., works the best for cavity damping.. AND it's CHEAP! win-win situation.

Cheers,
John

jpayne

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Re: Soundproofing basement suite ceiling
« Reply #11 on: August 05, 2013, 07:36:25 PM »
OK..I have decided I can do away with 1 4" electrical box....the other 4" round electrical boxes I am going to have to keep...so no MLV...should I go with putty pads or just do the box you mentioned?

jhbrandt

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Re: Soundproofing basement suite ceiling
« Reply #12 on: August 06, 2013, 02:04:24 AM »
Box it in, my friend. But if you can't, be sure to seal it well.

http://www.supersoundproofingsales.com/7-x-7-x-1_4-Acoustical-Sound-Blocker-Fire-Stop-Putty-Pads/productinfo/09-PUTTY+PAD/

but I would STILL recommend sealing the edges with a non-hardening caulk.
http://www.supersoundproofingsales.com/SSP-Acoustical-Sound-Sealant-Caulk/productinfo/09-42745-S/

or OSI SC-175, USG sealant, etc.

Remember that mass is your friend. If you can do it with the drywall, do it. ;) - But don't forget the sealant.

Cheers,
John

 

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