Roxul sound proofing opinion - Page 2

From what the experts have told me so far, there are diminishing returns on insulation when it comes to sound isolation, especially with low frequencies. in other words, once you have R12 insulation up, it is not worth it to add more, or get more expensive stuff, etc. Kinda like the 80/20 rule.

I had originally bought the safe n sound stuff, thinking it is better of course, then returned it the next day to pick up some pink stuff. For my 800 sq ft basement (not including the ceiling), I have saved myself about $300 that I can now put towards something else. So based on what Ted and Dennis have so graciously told me, I would recommend you do the same.

another consideration too, as mentioned in this thread (i think), is the ease of installation of the 2. If you have nice empty joists, the Roxul is no problem, but if you have alot of ductwork, wires, pipes etc to work around, the pink stuff starts looking a whole lot better (ignoring the itch factor.....)

This thread is great. Not because what's in it hasn't been discussed to death in other threads, but because all the information is in one spot, easy to understand, and backed by the people we respect the most on this site!

Everyone should bookmark it.

You just saved me a few hundred dollars as I was about to get thermafiber.

You also just saved me from hours of agonizing pain and itching.. and probably added a few years to my lifespan (the union guys don't call it 'the brown death' for nothing!)

Thanks!
Tim

If you have a Lowes, you should check out their new enviromentally friendly recycled polyester insulation from Dow.

Personally I think Safe and Sound is a good product and I'm happy with having used it in my theater. I think also that proper installation is at least as important of insulation type. Make sure it fills the cavity well. I have 2 sheets of drywall with a layer of Safe and Sound above it in my ceiling. It knocks down a lot of sound but my subwoofer can still be heard two floors up if I crank it. With the house shaking it is hard to contain that kind of noise without resorting to some very fancy and expensive designs. In the end I think my ducting system was the weak point in my soundproofing and no amount of insulation would prevent that leakage. IMHO

http://www.soundproofingcompany.com/.../the_dead_vent

Probably not of any interest at this point.

Interesting but too late for me. I did the conventional thing at the time which was to build in several bends in the ductwork to minimize problems. Still, I think it is a tough thing to do well and is a huge problem if you have spent lots of cash to keep sound in only to have it filter through your house in the ductwork.

I'm glad I found this thread! I have a drop ceiling (300 sq. ft) in my basement with zero insulation. When I hit 90 dB SPL in the basement (receiver at 10 less than reference), I'm getting 70 dB SPL in the living room above.

I want to insulate my ceiling. I have 18.5" inch gaps between the wood studs and I was about to buy some 24" Roxul S&S tomorrow and start sticking it in. Now I'm hearing that the pink stuff is as good, if not better.

Which Pink should I get? How do I keep it up between the joists? Should I use a plastic vapor barrier stapled to the joists to hold up the pink stuff from falling down onto my drop ceiling's tiles?

Thanks in advance!

I got Safe n Sound for two reasons:

1. I didn't know better.

2. I got it for less-than-retail.

Anyway. Since SafenSound doesn't come with an r-rating, what's the recommended thickness of it to use. For no good reason, I assumed that two layers would be better on the ceiling.

I can always return unused batts, so I will go with a single layer if that's what fits into the law-of-diminishing return.

So in my basement, I have the engineered I joists, and it takes two batts of R19 to fill it (see on the left)



A) Should I be using two batts, or is one good enough (leavings some air)

B) If using 2 batts, should I remove the paper off of the batt I put in first, or should I leave it, and if so, should the paper be going up or down on the first batt?

C) Should I staple it in place or leave it floating?



D) For the spaces where the HVAC ducts run, I've been peeling the paper off of R19, cutting to size, and installing as shown above, does this look good? Any problems with packing in the vents? I've seen other people do it, but the wife was questioning it.

E) I know insulation comes in many colors, but why does it look like all the outside wall locations have yellow insulation? Is there any difference with the pink stuff?

Great thread - I've already learned so much, and its nice to have it all in one spot!

I think you may have compressed that insulation a tad too much. You have 16" OC joists. The duct appears to be 6"

That leaves about 8" of air, divided by 2 = 4" of clear air on either side of that duct. You should be using R13.

In a typcal joist cavity, there is little improvement when going beyond 6" of insulation (R19) even though you could stuff R30 in there.

There's no magic to which fiberglass to use. Faced, unfaced, pink, white or yellow.

daMaster, are you going to be drywalling the ceiling, or leaving suspended?

Ted,

Can that Dead Vent design be incorporated as a "muffler" of sorts before it is connected to the HVAC system as opposed to just an exchange of air in the basement? In other words, build the same set up (minus the variable speed fan) outside the theater for the supply line to run through into the theater, and then build the set up (with the variable speed fan) for the venting of air outside of the theater? I think it is a pretty cool concept and originally my plan was to just use 6" flex duct from a hard supply and then put in a passive vent (with flex duct) into the remainder of the basement as a return. I can still build something like this though if I will see some real improvements on the supply side, which will be tied in to my HVAC system.

Thanks!

Greg

Hello Greg,

Yes, absolutely. The Dead Vent is not exclusively for room exchange. You can certainly use it with the main HVAC

I'll be leaving the ceiling suspended. Should I go with R12 (3.5") or R20 (6")? It's going to cost me about $88 CDN more if I go with the R20 to cover the ~300 sq. ft. I'm willing to spend that extra dough if there'll be an improvement with the R20 over the R12. Especially since I was about to spend more with Roxul before I found this thread.

I'm looking to get the 19" wide version since my joists are about 18-19" apart. How should I keep the pink stuff held up in the ceiling? Will it just hang there or will I need to use wood slats or plastic sheeting stapled to the joists?

Thanks in advance!

Well, since the ceiling is suspended tile, your isolation is going to be limited / defined by that. So I'm really not sure you will get any benefit going from R12 to R20.

Thanks Ted. I'm not sure if I'm reading what you're saying right but are you suggesting that any amount of insulation won't make a difference due to my suspended ceiling? Or are you saying that R12 will make a difference and will be good enough? As I mentioned earlier, I'm currently only getting a 20dB loss through the un-insulated suspended ceiling from the basement up to the living room. If I can reduce the transmission of sound and get a 30-40dB loss I'll be very happy.

I'm thinking you'll get a benefit from adding some insulation. Because of the ceiling I'm just not sure I can recommend going beyong R12

Thanks! R12 it is then. Any ideas how to keep it up in between the joists? Will it just stay there or should I put plastic sheeting over it or wood slats?

Well, I'd double check the dimensions and make sure that you're not actually describing a 16" on center framing. If your joists are in fact 16 OC then just get standard paper faced insulation and staple it up. Even if slightly wider than 16", the paper edges on paper (kraft) faced insulation unfolds and extends out quite a ways to accommodate a wider joist cavity.

Don't mind that the insulation doesn't span between the joists. That small gap isn't significant

Ted - do you mind giving your input here? I have a similar issue with insulation and soffits. Thanks!

http://www.avsforum.com/avs-vb/showt...8#post15414478

Given that Roxul does not publish "R" values for Safe N sound (I know, I shoulda got pink), what is the "right" amount of safe-n-sound to use in my ceiling

Given the theory that "more is not better," I was just going to go with one layer of 3" stuff and call it a day.

Thoughts?

Mac, 6" would be ideal in a ceiling

My joists are indeed 19" apart on center. Turns out Home Depot doesn't stock the 19" wide R12/R20 Pink, only on special order. I ended up getting the 23" R12 and was planning to cut the 48" batts into 19" segments and stick it in perpendicular, but then we started to squeeze in the 23" and they fit with a bit of folding on the sides as such:




We did a quick test without the ceiling panels back in place and I was still getting the same 20 dB loss from basement to living room above with only the fiberglass, i.e. 95 dB in basement/75 dB in living room. I'm really hoping that it'll be better once the ceiling panels are back in (they are 2'x4' 5/8" Armstrong Sonoflex fire-retardant, sound reduction fiberglass panels).

Is the way I installed them acceptable or will it defeat any possible sound-proofing characteristics of the pink?

That's perfectly fine. Just make sure to pull the center down a tad to un-compress

in regards to insulationg a ceiling, i need some help. i have 2x10 joists, followed by a 6" air space, and then a 2x4 independant floating ceiling for my theater. so total joist air space is about 20". other than the fact that anything more than r12-19 is sufficient, is it advisable to stuff this entire 20" air space to avoid resonance, or can i simply put up r19 at the top of the 2x10 joists and have about 15" of airspace in the cavity? will this act like a drum and should i competely insulate this space?

For a suspended ceiling, after the insulation, you can cut 1/2" drywall to the same size as your ceiling tiles and install the drywall behind the tiles. That will provide some additional mass and will help a bit.

Anthony, R-19 should be fine. Adding a layer of R13 wouldn't hurt, but you don't need to completely fill that 20"

I read the dead vent article and one of the things I noticed on it was mention of simply exchanging air with the rest of the basement.

"For many rooms including basement home theaters and recording studios, you may only need to consider cooling the air in the room by exchanging this air with the remainder of the basement air. Basements are obviously naturally cool all the time."

So a couple questions:

How do you make use of this option? And is it effective in Canada with our cold winters?

There are a lot of people who have done this over time. I did and it works well.

I would rather have a dedicated mini-split

I'm sure it's been done and successfully. I guess I'm hoping to find somewhere that better describes it. I looked on the soundproofing site and didn't see any articles specifically on that.

Also a lot of people don't have -50 celsius temps in the winter, so I want to be sure any solution I take will work for our climate.