Basement Sound-Proofing

[Laneco]

This may not be applicable but when I was noise proofing the base in my house I was trying to keep every one from hearing the people i keep lock up down there.
The voices can be keep down to a low murmur with some perimeter mattresses and electrified collars. If this is helpful let me know and ill send some schematics.

Steve

[Eric Coffey]

Originally Posted by Laneco

This may not be applicable but when I was noise proofing the base in my house I was trying to keep every one from hearing the people i keep lock up down there.
Steve

It rubs the lotion on its skin or else it gets the hose again!

[Laneco]

Eric your my kinda people's

Steve

[onewhippedpuppy]

I prefer to kill my victims before I put them in the basement.

[porsche4life]

C'mon Matt you know you are just trying to make it to where you can sneak in and catch your kids when they get older....

[Laneco]

I tried that a time or twooo but they always started to smell so now I keep them alive. On a side note they are far more interactive now.

Steve

[mschuep]

Sorry to be chiming in late, this just happens to be in my area of knowledge and I didn't see the thread...

Are you only concerned about footfall noise? Do you care about airborne noise as well, such as voices, TV, etc?

Can you list your current floor/ceiling assembly, such as:

finished surface (carpet and pad, tile, hardwood)
plywood or OSB subfloor
2x10 joists at 16" o.c., or open web wood joists @16" o.c.

Also, you mentioned that you are planning to put in wood/tile in certain areas...are these areas directly above where you are finishing out the basement?

There are two ways for the noise to get from one floor to another. In multifamily(apartment/condo) buildings these are rated in terms of Impact Insulation Class(IIC), and Sound Transmission Class(STC)...Footfall noise is primarily related to IIC. It needs a different solution than airborne noise. The international building code has requirements that new construction must meet for STC/IIC, just as it has structural, electrical, plumbing requirements as well.

While sound insulating batts (insulation) do help the STC rating of an assembly to some degree, it has been well documented that insulation does very little to increase the IIC of a floor/ceiling assembly. Furthermore, adding additional layers of drywall (or dense drywall products, such as quietrock) don't do a whole lot either for IIC. Neither does a dampening product in between multiple layers of drywall. And fiberglass ceiling tile, while it does absorb sound, it is not good at all at stopping sound. Many generic ceiling tiles, and certainly plain gyp board, has a lot higher CAC rating than lay-in fiberglass tiles.

Depending on the structure of your assembly, and the finished floor material, you can have one heck of a problem trying to decrease impact noise. The only way to make it better is to isolate the top from the bottom. This is usually accomplished through the use of resilient underlayments on the topside underneath the finished floor, and/or resilient channels or mounts on the bottom side between the structure(joists) and the drywall.

In addition, if you are on the perimeter of the building or near walls that extend through both floors, you need to isolate the ceiling and floor from the walls, with the use of non-hardening caulk, etc. Any rigid connection to the structure will 'short circuit' your assembly, and reduce the overall performance.

If you give me a little more info, I can try to help out with some product info, and general recommendations...bottom line is that you will need to spend some additional money, and likely take some more time during construction to ensure that little things are done correctly.

Even then, if you have hardwood floors or tile, and wood joists, you will still be able to hear the people above...just much less noticeably.

[911pcars]

Originally Posted by onewhippedpuppy

I prefer to kill my victims before I put them in the basement.

Exactly. Anything I hate worse is to being able to hear screaming and yelling from my basement.

A concrete and padded sub-basement seemed to have worked wonders for that Austrian family dude.

Sherwood

[RWebb]

Matt - I have a similar issue, and will send you a pm.

[onewhippedpuppy]

Matt, I want to reduce mainly footfall noise. The floor above is 3/4 plywood subfloor, 2x10 lumber floor joists 16" OC. When we remodel on the main floor, the kitchen, entry, and 1/2 bath will be ceramic tile. The remainder of the rooms will be hardwood. Any advice is appreciated. With my framing complete, I believe that limits many of my options. Ultimately I'd like to reduce noise, but I don't want to spend a huge amount of time and money on it.

[mschuep]

Ok, well as I mentioned the footfall noise is mainly due to noise transmitted through the structure.

So, therefore, you need to try and isolate the structure from the finished floor, and the finished ceiling.

Please realize that no matter what you do to the f/c assembly, not all the noise is going to go away. The type of noise that is especially problematic with this type of structure is the low frequency footfall noise, aka "elephant walk" noise, as the attenuation of such noise is more related to the mass and stiffness of the assembly than the thickness or the materials...Also, carpet+pad does an excellent job topside for reducing the mid-high frequency impact noise. You will notice a drastic difference in impact noise when you replace it with tile/hardwood. There are things you can do which you should consider when installing the tile/hardwood too...

Anyway...We'll concentrate on the ceiling since that is what you are currently working on.


I would recommend the use of resilient channels (RC) or sound isolation clips, in addition to sound insulating batts in the stud cavities. The general idea behind the RC's and clips is the same, 1) they help minimize (or eliminate) direct structural contact between finished ceiling and ceiling structure, therefore minimizing the structural noise transmission 2) they allow the ceiling to move slightly, which makes the floor/ceiling assembly and airspace act kinda like a diaphragm, which absorbs more airborne sound. Either one of these is rated to support 2 layers of 5/8" drywall. 2 layers is better than one, but not by a large amount, expecially for impact noise. If you have the means I would do 2.

In general, the clips do a better job, and they are easier to install, but they are a bit more expensive per sqft. Also, the RC's will only take up additional 1/2" of vertical space, while the clips will eat up about 1.5".

For the RC you'll want to use the 25 gauge Dietrich RC Deluxe. I'm not sure how easy these are to find for small scale installations, but, they are the only RC we recommend due to the vast differences in performance among RC's:
http://www.dietrichindustries.com/products/pdf/52_53_DMF07.PDF

For the Clips, there are a few options out there now, but the most common is the PAC RSIC-1, made by Pac International. http://www.pac-intl.com/pdf/RSIC_Advantage.pdf

Again, I'm not sure exactly how to locate these on a small scale. Best bet for either option is probably google, or by calling local manufacturer's reps to see if they will offer to sell you a small amount of channels or clips. These are primary used on large-scale multifamily buildings, since there is obviously no code within the same residence, and builders of single family homes typically do not go to large extents for sound isolation from floor to floor, or room to room.


The RC's install perpendicular to the joists at 24" o.c.. You attach the small, single leg to the wood framing, and then screw the drywall to the other 1-1/2" screw flange that is down 1/2". DO NOT screw through the flange and the joist!

The clips are screwed directly into the joists, and then you snap on a standard hat-track, which you would have to run every 48" o.c. perpendicular to joists. You then simply attach the GWB to the hat track. IIRC you should only have to use 1 clip every other joist, but check their site for exact details on installation. Here this should help http://www.pac-intl.com/ppt/RSIC-1_Wood_Steel_Install.ppt#1

In either assembly it doesn't matter whether the insulation is in the top or middle or bottom of the cavity.

When you are installing either assembly, careful consideration must be given to the perimeter isolation of the ceiling, and any fixtures you install in the ceiling. You should cut the sheetrock 1/8"-1/4" short, and then fill in the gaps around the perimeter with non-hardening caulk. If you do crown molding, install it just under the ceiling and attache to the wall only. DO NOT rigidly attach it to the ceiling and the wall, as this will also short circuit the assembly.

Same goes for fans, lighting, etc...you can't rigidly connect stuff to the 'floating' ceiling and the ceiling structure without compromising some of the acoustics.

I hope this helps...If you have more questions or want info on the finished floor installation let me know and I will try to slap some more info together for you.

[RWebb]

so the rubber clips would do a better job than 2 layers of sheet rock with Green Glue in between them?

a much better job? slightly better?

and what about the Quietrock - is it of much value?

thx!

[onewhippedpuppy]

Originally Posted by RWebb

so the rubber clips would do a better job than 2 layers of sheet rock with Green Glue in between them?

a much better job? slightly better?

and what about the Quietrock - is it of much value?

thx!

Ever price Quietrock? In my case, I found it to be about 10x as much as regular sheetrock.

Matt, thanks for the info. What do you recommend to cut down on noise with ceramic or hardwood? That work is all yet to be done, I'm finishing the basement first.

[mschuep]

Originally Posted by RWebb

so the rubber clips would do a better job than 2 layers of sheet rock with Green Glue in between them?

a much better job? slightly better?

and what about the Quietrock - is it of much value?

thx!

Randy, the clips would do a much much better job than two layers of GWB with green glue in between. I would not expect any appreciable difference from two layers of GWB, compared to two layers of GWB with any type of resilient glue in between. I have seen test data, and installations, where the contractor has mistakenly put the RC in between the two layers of gyp instead of in between the joists and the 2 layers of gyp. The results are as if the RC is not there, because the cavity isn't large enough for the resilience of the assembly to have an effect (or affect)

Quietrock, while it is a worthwhile product that has its place, it is very expensive for what it does...on the order of 8-10x what a normal sheet of GWB is, like the other Matt said. IMO, in most cases you are better off slapping on additional layers of GWB instead of paying the premium for quietrock.

FYI (and IMO) Their marketing and test data, albeit accurate, doesn't exactly present an apples to apples comparison...

[RWebb]

THX!!

effect for that one...


BTW - what thickness of sheet rock do I need to use with them thar clips?

[mschuep]

Randy, as far as your question on 1/2" vs. 5/8" GWB, I would have to do some research to give you a difinitive answer...

My feeling is that, theoretically, you are not going to see a whole lot of difference...At least when it comes to an official IIC or STC test.

However, I would think that in general, the 2 x 5/8" is going to isolate better than the 2 x 1/2" simply due to the fact that it has more mass. More mass means more attenuation, especially at low frequencies. But, compared to the overall assembly, it probably won't have a noticeable effect.

It is likely to be dependant on the specific assembly, and the airspace depth, type of GWB, etc.

[RWebb]

Well I priced some RSIC clips the other day and the were $6 each. The spec. is every 16 OC, so that is a freek load of these things, adding $1,000 or more to the cost of my new ceiling.

In other words, out of the question.

But thanks for the info.

[onewhippedpuppy]

Randy, that's why I ended up just insulating the ceiling. Footfall noise like kids running above is still audible, but dampened. I haven't sheetrocked it all yet, so that should further help. I can't say I'm happy with it, but it's better than nothing. Ultimately the cost to sound-proof it the right way just didn't align with my intended use for the basement.

[davidki]

In my recording studio we used Rockwool. really nasty stuff to work with but it beats the pink stuff hands down. You can use a silicon based glue to put on the joists and then screw the first layer of 5/8" drywall. Then put another coat of silicon based acoustic sealant on the first layer and put the 2nd layer of 5/8" drywall on that and screw it in. I think my depth of rockwool is 12" rockwool. Hope that helps, contact me if you need more info.