Soundproofing With Insulation ???

I'm planning on stuffing my ceiling with insulation. It will definately help.

Yep But stick to something not more than R19. Any more and it's really diminishing returns

I filled mine with R38. I didn't do any other sound-proofing either, and although I'll probably wish it was better, I do think it definately helped.

stuffed mine with R38 as well.

stuffed mine with r25. also, wrapped the duct work with specific duct wrap insulation. i am greatly impressed and satisfied with the results. the majority of sound stays in the room, which allows me to watch movies nice and loud well into the night .

Remember that insulation in a cavity is just one component of sound isolation. You can have your choice of any porous insulation in the world, and still have lots of sound travel through! Lots of mass, thickness, sealing, decoupling (and/or viscoelastic damping) -- these are required components.

Regards,
Terry

Exactly. Again, you needn't fill every cubic inch of space. There's a large performance difference between a cavity that is 0% filled and 50% filled. Not such a difference between 50% and 100%.

Diminishing returns after R19.

R38 in my ceiling plus double-drywalled. R13 on all surrounding walls as well.

Check out Roxul Acoustical Fire Blocking batts.

Best solution I found for "sound deadening" insulation. (AFAIK, FAR better than Rxx).

I used this - but in addition to RSIC clips, DD/GG, etc. Room is WAY quiet!

- B

I was thinking about have my ceiling joices filled with blown in insulation. I would think it could get to all the nooks that I could not get to with rolled insulation. I hope my thinking is sound (no pun intended).

Standing on Soap Box with megaphone:

Anything more involved or expensive than the cheapest R-19 (6") fiberglass you can find isn't going to give you a real benefit. Way too much benefit is tied to insulation. Why? Because it's intuitive that insulation should work. It does work, obviously, but only to a point in practical terms.

But it doesn't take much insulation to provide absorption in a cavity. That's where people get hung up. You don't need thicker than 6", but you can if you want, certainly. You don't need anything beyond cheap fiberglass, but you can if you want, certainly.

Save your money and invest in other aspects that will really give you gains. Like decoupling, mass (extra drywall) and damping.

Combining these elements will certainly provide more isolation. Don't blow the whole budget on just the insulation.

I put R30 in the ceiling, and R-19 on the sides. I'm then planning on adding mineral wool against this insulation. Any issues with this? Am not going to do the double dry-wall/GG method.

Thanks.

You are adding mineral wool to the fiberglass? You won't hear a benefit. I'd suggest taking the cash and just add another sheet of plain ol' drywall. You'll hear a benefit from this.

At least double up on the drywall, staggering the seams and filling all the cracks with non-hardening caulk. Unless of course you don't care about sound isolation. Just insulation will provide essentially no sound isolation benefit.

Regards,
Terry

Seems like I've read threads on people adding the mineral wool, or using it exclusively - time to go back to the Acoustics Thread, and do some re-reading.

I was thinking of adding additional layer of drywall on the ceiling - the sides are mostly concrete (poured foundation), however, the back and 1/3 of a side is exposed to the other rooms.

See this photo:

The only circumstance where this might be effective is when you have several feet of thickness to fill with porous insulation. And even then, you will have low frequency blocking problems. This technique is sometimes use to treat flanking noise.

Regards,
Terry

Exactly. If you had a cavity depth of a couple feet, you would consider more than R19.

Side note: such a wall, if decoupled and loaded with mass would have quite a low resonance point. Great for a theater owner with tons of subs.

The data collected by the NRC in Canada concludes that for absorption in walls, you're not going to do any better than cheap fiberglass. If you get mineral wool at the same price, go for it. If your cousin blows in cellulose, great! But the data indicates the performance isn't going to be better from a practical standpoint.

And please don't overstuff. Leave light and fluffy.

Everyone should really be darned glad. This is one of those times that the cheapest material available is also the best choice.

Ted & Terry -

Many thanks for the guidance - very good to know. I've updated my HT thread regarding options I'm considering - really appreciate it.

Just want you to get a good bang for the buck. No sense wasting funds when you have so many other things that need buyin'!!

Ok
So I have 12" silent floor joists stuffed with insulation. I removed the sheetrock and placed furring strips going the opposite direction. The furring strip are to lower the rsci clips and hat channel to clear a gluelam beam. This gives me about 3 1/2 " of space between the floor joists, insulation and the new sheetrock.
The question is should I fill this space with r-13. This insulation would be going the opposite direction and give me a good seal under the floor joist.
What I am reading here is to NOT spend the time or money and leave it an empty air space?
double 5/8" and GG will be added to the hat channel.
??

I would not recommend adding insulation. The cavity as defined by the subfloor above and double drywall below is insulated. As long as the existing insulation is not foam (foam is not ideal for acoustic use) you already have good absorption in that cavity.

Save the $$ and be happy.

Just the thread I have been looking for, thanks longwa!

What can be used to hold the unfaced R19 up between Engineered I-Joists where the openning is wider (15.5") than solid wood joists?

..Or is R19 wide enough to stay stuffed in place until I drywall?

Insulation is sized to "friction fit" between joists that are separated by standard dimentions of 16" and 24" on center.

Good question. Also, paper faced or unfaced doesn't matter.

The joists are standard 16" on center but the gap is 15.5" instead of around 14.5" for wood joists. In my last house I used rigid (Insulation hanging) wire that was 15.5" but that will not work here. Any ideas?

I will used unfaced becuase, as Ted said it does not matter, and it is likely cheaper.

Plex, just curious what the joist material is that is only 1" wide.

Insulation for 16" on center framing is actually 15" wide, so you would need to use kraft paper faced insulation that has paper flanges that will cover the joist span. Staple in place.

One of the reasons I used an R38 in the ceiling was to try to keep some heat from rising into the upper floors.

Ted, the verticle material looks like OSB, and the top and bottom of the I-beam are made of a 1.5" laminate like plywood.

Mine look just like this pic: http: //www .qualifiedremodeler. com/images/article/1154380081297_wood5.jpg

THat's a standard I-beam. Truss-Joist, TJI, etc. The important dimension isn't between the OSB sections, it's between the bottom 1.5" pieces. The insulation will rest in between the joists on top of those bottom flanges. That's the theory. I have those joists also, but used paper faced and stapled.