Best soundproofing material in between ceiling joists

[suprstar]

I am starting up a new band that will be practicing in my basement. I need to soundproof as well as possible, my budget is around $1k. Soundproofing is my #1 goal, unlike most of the other posts I'm finding. I'll deal with room acoustics eventually, but I need quiet first - our first rehearsal is in 3 weeks. We'll be kinda quiet anyway, the drummer will be using my v-drums, so we'll all be able to turn WAAAYY down to begin with.

The room is appx 20'x15', and the bottom of the ceiling joists are exactly 8'. The ceiling joists are appx 1 foot deep (11 7/8 I-joists), so I can pack a lot of fiberglass batting, closed cell foam, rockwool, etc. The plan is to pack whatever in between the joists, and hang drywall to the ceiling. I may also add a layer of green glue and a 2nd layer of drywall if time/$ permit. The drywall is no prob, I'm wondering about the filler.

For the joist cavities, has anyone tried this closed cell foam?
http://www.bestchoiceinsulation.com/_mgxroot/page_10812.html
It claims to absorb sound VERY well, and costs about $1 per cu. ft installed. A few hundred bucks for the whole ceiling.

Otherwise I'll probably just stuff as much fiberglass batting in there as possible. I am also considering a 2" layer of Roxul AFB mineral wool, and stuffing the remainder of the space with fiberglass batts. Pricier, but if it works better I can swing it.

OC703/705 is out of my price range, and I beleive 12" of batting or cc foam will provide better sound absorption than 2" of ANYTHING, even OC705. Is that true, or is the OC stuff really that good? Not to mention I can get all the batting I want locally in minutes...

I'm hesitant to try resilient channel, because they say most ppl screw up the install, then it has little to no effect.. Costs too much for me to risk it so... I know it won't be perfect, hopefully it'll be enough.

My last concern (currently) is this: One of the 15' sides opens up to the rest of the basement, about a 30'x30' square room with the stairs in the middle. I'm not going to be treating those ceilings right away because they're under different rooms where I don't care how loud it is up there. But if it's loud in the kitchen or dining room, that sound will bleed into the family room, hopefully at sufficiently low levels.

Any additional tips, thoughts, ideas, etc before I start buying materials? Thanks,

 

[Freudian Slip]

I am starting up a new band that will be practicing in my basement. I need to soundproof as well as possible, my budget is around $1k. Soundproofing is my #1 goal, unlike most of the other posts I'm finding. I'll deal with room acoustics eventually, but I need quiet first - our first rehearsal is in 3 weeks. We'll be kinda quiet anyway, the drummer will be using my v-drums, so we'll all be able to turn WAAAYY down to begin with.

The room is appx 20'x15', and the bottom of the ceiling joists are exactly 8'. The ceiling joists are appx 1 foot deep (11 7/8 I-joists), so I can pack a lot of fiberglass batting, closed cell foam, rockwool, etc. The plan is to pack whatever in between the joists, and hang drywall to the ceiling. I may also add a layer of green glue and a 2nd layer of drywall if time/$ permit. The drywall is no prob, I'm wondering about the filler.

For the joist cavities, has anyone tried this closed cell foam?
http://www.bestchoiceinsulation.com/_mgxroot/page_10812.html
It claims to absorb sound VERY well, and costs about $1 per cu. ft installed. A few hundred bucks for the whole ceiling.

Otherwise I'll probably just stuff as much fiberglass batting in there as possible. I am also considering a 2" layer of Roxul AFB mineral wool, and stuffing the remainder of the space with fiberglass batts. Pricier, but if it works better I can swing it.

OC703/705 is out of my price range, and I beleive 12" of batting or cc foam will provide better sound absorption than 2" of ANYTHING, even OC705. Is that true, or is the OC stuff really that good? Not to mention I can get all the batting I want locally in minutes...

I'm hesitant to try resilient channel, because they say most ppl screw up the install, then it has little to no effect.. Costs too much for me to risk it so... I know it won't be perfect, hopefully it'll be enough.

My last concern (currently) is this: One of the 15' sides opens up to the rest of the basement, about a 30'x30' square room with the stairs in the middle. I'm not going to be treating those ceilings right away because they're under different rooms where I don't care how loud it is up there. But if it's loud in the kitchen or dining room, that sound will bleed into the family room, hopefully at sufficiently low levels.

Any additional tips, thoughts, ideas, etc before I start buying materials? Thanks,

Your main problem is going to be having the ceiling attached to the floor joists. I don't know if resilient channel is good for suspending ceiling drywall. I'd check into it and if it is I would use it along with two layers of drywall with green glue in between. I don't think that anything light like foam will do you much good. I would just stick with fiberglass insulation for fire safety. Over do it with the insulation if you want so it's packed in there. Bass is going to be the main problem though and mass is going to be your friend. That and decoupling the ceiling from the floor as much as you can while still having it be safe. taAlso caulk the drywall joints before any taping.


Good luck

F.S.

 

[bpape]

Standard insulation in the cavities will be fine. Don't even need to stuff it, just fill it full.

RSIC-1 and hat channel before the drywall is IMO the best way to decouple things. You can add another layer and Green Glue later as money allows. It's a good thing to do but something you can do later - unlike doing the decoupling.

Bryan

 

[suprstar]

Thx for the reply, stuffing as much batting in the cavities as possible doesn't do any more good than just lightly filling them up? Or is the difference just negligible? I'll be placing an order for quite a bit of it today, I was planning on buying a ton and really stuffing it in there as tight as possible. It's more mass right?

I'm checking out decoupling options, but I'm nervous to buy, because I'm afraid of screwing up the install and shorting out the decoupling, thereby wasting tons of $. One site I saw said 90% of resilient channel installs get screwed up and the... The idea is to build all the framing normally, then decouple the drywall from it, correct?

Or is there anything I can do to help decouple any framing from the joists? Like an inch of rubber strip or something? I'm going to anchor as much framing as possible into the concrete, but some is going to have to connect up with the joists at some point..

Also, I have to build against an exterior wall that's already framed and drywalled, and coupled.. Unless I build ANOTHER wall right up against it. I'm not worried about sound getting outside, but it will transfer. I think I'd rather just green-glue and do another drywall layer on it, I hope that helps somewhat.

 

[bpape]

RC is very easy to mess up and is unpredictable in terms of internal room response. RSIC-1 and hat channel is MUCH better at isolation and is very predictable and hard to mess up.

The last thing you want to do in the cavities is jam in in there really really tight. You can get it to a point where it couples the drywall to the surface above. Just fill the cavity. A little compression is fine - like putting 12" in a 9-10" space.

Bryan