Soundproofing

How did your job turn out?

Posted by: Ted White at July 25, 2009 5:30 PM in response to soundproofing green glue FS

Soundboard is really not what you want in or on your walls. I say this based on many independant acoustic lab tests. Certified data.

All you have is mass, absorption, decoupling and damping. The only 4 elements you can bring to bear here.

It is of little mass, so it doesn't help there. It is too compact to offer any absorption. It offers a very small degree of decoupling, and no damping (of the drywall panels) at all.

Great in floors, though.

Even a shoddy building has some mass, so this is most likely a sound leak, rather than going through your walls. So before I spent a nickel on soundproofing materials, I would identify the leak(s):

Door seals
Outlets
Gap under drywall (remove base moulding and see)
Ventilation

I assume you have a drywalled ceiling. Do you have any air vents of any kind on that wall, or close to that wall?

Posted by: Ted White at July 25, 2009 5:20 PM in response to Sound Permeating Walls

"This seems intuitive, but not the case. Sealing small gaps in the ceiling will technically inprove things, but results will likely not even be able to be measured."

This would be for a small crack on the ceiling (assuming some insulation up there).

I wanted to clarify this point. If the "crack" was a clear opening from downstairs to upstairs, you'll have a REAL problem. Like the gap around a pipe.

From that perspective, Ed Rex is on the money.

Posted by: Ted White at May 27, 2009 3:34 PM in response to ceiling soundproofing

http://www.soundproofingcompany.com/library/articles/elements_of_room_construction

You are up against a lot.

Posted by: Ted White at May 26, 2009 3:26 PM in response to soundproofing

To clarify, carpet will help with footfall in the higher frequencies, but not airborne.

Quote:

"If you have openings in the ceiling closing them will give more than a little improvement for air borne noise and an extra layer off sheetrock helps to seal and consolidate a compromised ceiling."

This seems intuitive, but not the case. Sealing small gaps in the ceiling will technically inprove things, but results will likely not even be able to be measured.

I already described the problem with relying on additional drywall. The expected results from the addition of mass follows Mass Law. While there is a difference, this difference may very well fall below the threshold of hearing. You may not hear a difference.

Posted by: Ted White at May 26, 2009 12:03 PM in response to ceiling soundproofing

A few common myths surfacing here:

Green Glue and Quiet Rock both work as represented in the independant lab tests. Perhaps a salesperson is exaggerating. Flanking is generally the biggest reason for a compromize in performance.

Acoustical caulking a floor does almost nothing. The problem does not boil down to a hairline crack of some sort.

You do not pre-drill holes to attach drywall to either resilient channel or metal Drywall Furring Channel.

While footfall (impact noise) is reduced with carpet and pad, it will do very little for airborne noise, especially lower frequencies.

Adding a single sheet of drywall alone to an existing ceiling will do little. To increase 5-6 STC points you have to double the weight of the entire floor/ceiling assembly (flooring + joists+ ceiling drywall). So adding only 1 sheet to an existing ceiling might get you 1-2 STC points. A lot of work for the performance gain.

Posted by: Ted White at May 26, 2009 9:29 AM in response to ceiling soundproofing

A few common myths surfacing here:

Green Glue and Quiet Rock both work as represented in the independant lab tests. Perhaps a salesperson is exaggerating. Flanking is generally the biggest reason for a compromize in performance.

Acoustical caulking a floor does almost nothing. The problem does not boil down to a hairline crack of some sort.

You do not pre-drill holes to attach drywall to either resilient channel or metal Drywall Furring Channel.

While footfall (impact noise) is reduced with carpet and pad, it will do very little for airborne noise, especially lower frequencies.

Adding a single sheet of drywall alone to an existing ceiling will do little. To increase 5-6 STC points you have to double the weight of the entire floor/ceiling assembly (flooring + joists+ ceiling drywall). So adding only 1 sheet to an existing ceiling might get you 1-2 STC points. A lot of work for the performance gain.

Posted by: Ted White at May 26, 2009 9:29 AM in response to ceiling soundproofing

Tough Issue, really. Footfall noise is always harder to eliminate than airborne noise. This explains what you're up against and some options. http://www.soundproofingcompany.com/solutions/neighbor_noise/neighbor_noise_ceilings

Posted by: Ted White at May 25, 2009 1:00 PM in response to ceiling soundproofing

Here is a diagramed step by step list of options. Ceiling (footfall) noise is harder to deal with than airborne. http://www.soundproofingcompany.com/index.php?/solutions/neighbor_noise/neighbor_noise_ceilings

Posted by: Ted White at February 3, 2009 9:20 AM in response to ceiling soundproofing

Unfortunately, footfall noise is the most difficult to deal with. The direct impact injects a great deal of energy into a small area. This easily overwhelms most isolation systems and products. This is distinctly different from isolating airborne noise. An analogy is surviving a rifle vs. shotgun. Footfall = rifle. A TV set = shotgun.

Thin mats and pads don’t offer much relief at all. Again, very easily overwhelmed by the impact energy of a footstep. Their success is limited to the high frequencies (low energy) and not the more bothersome thumping low frequencies.

Here’s an article with data and graphics that explains the footfall noise problem in detail. http://www.soundproofingcompany.com/index.php?/solutions/neighbor_noise/neighbor_noise_ceilings

I am affiliated with this company, so let me say that for full disclosure.

Given that 95% of the time the problem can only be dealt with from below, generally the best results are obtained when you:

Remove the existing ceiling
Apply mass and damping to the underside of the subfloor
Install simple run of the mill R19 fiberglass insulation
Decouple the new ceiling drywall from the old joists
Install new drywall.

This is a multi-faceted approach that works best, and is a good bang for the buck. Exotic insulation does no better than R19. Lab proven fact. You can assemble your own “soundproof drywall” and have better, far less expensive results. Another lab-proven fact.

If you focus on the fundamentals, you can really improve things a great deal.

Posted by: Ted White at January 29, 2009 4:19 PM in response to Soundproofing

I agree with Gennaro that the Quiet Rock is a bit expensive. You can assemble your own panels with standard drywall and glue.

Green Glue has 4x the damping capacity of Quiet Glue. Independently tested.

The resulting wall is heavier and more damped. Two key factors.

I'd suggest not packing the insulation. Lab data shows a light, low density (normal) pack is best. Too packed and the insulation will actually act as a conductor.

Posted by: Ted White at January 23, 2009 4:39 PM in response to Soundproofing finished basement

Then you should consider decoupling the new drywall from the existing framing. Much less vibration transfer.

Then insulate with simple fiberglass. R19 in ceiling, R13 in walls.

Posted by: Ted White at January 23, 2009 3:36 PM in response to Soundproofing

Is there existing plaster or drywall? Or do you have an open joist / stud cavity?

Posted by: Ted White at January 23, 2009 12:32 PM in response to Soundproofing

Then you should consider decoupling the new drywall from the existing framing. Much less vibration transfer.

Then insulate with simple fiberglass. R19 in ceiling, R13 in walls.

Posted by: Ted White at January 23, 2009 3:36 PM in response to Soundproofing

Any thoughts on soundproofing a ceiling from percussive noise from upstairs neighbors? No current insulation, just their floor, a foot of dead air and our ceiling. Had two contractors - one was outrageous and the other recommended blowing foam. Help?

Posted by: ralphus999 at January 23, 2009 5:00 PM in response to Soundproofing

Ralphus,

I am about to rip up my new floors (luckily I have not had them stained yet) to put down a product called quiet cork in between the subfloor and a new reinstalled finished floor. It usually goes between the joists and the subfloor. It is by far and away the best for footfall sounds (I did a great deal of research). I am doing this because I want to have a luxury (re:high rental) unit on my garden level and I feel strongly that hearing every step my family (2 kids, lots of teenagers over all the time) takes would drive someone crazy. If you are planning to have a rental unit, it would be well worth it to do this before you finish the renovation. My architect did not advise me well (at all in fact) and even though I have fiberglass for fire rating, it does nothing for the impact sound from above. Blowing foam is not as good as quiet cork!. Just out of curiosity, what did his outrageous bid contain?

Posted by: homey at January 23, 2009 7:03 PM in response to Soundproofing

Sound transfer is primarily about 2 things. Uninterrupted cavity space and direct transfer through a medium.

In floors you have 2 issues. Your flooring sits on subfloor which is tied directly into the joists. There's a cavity between the joists that is typically uninsulated and then drywall for the lower level's ceiling.

I've experienced three options here. One, put down cork under your flooring. there are also mass load vinyl products for this as well that deaden noise. Two, insulate with a dense foam to kill dead spaces - there's a difference in various products by weight here, denser is better. And finally, you can completely decouple your joists for your floor from your downstairs ceiling joists. Much more complicated but boy... it really kills the noise once the cavity is filled.

Posted by: Loub at January 24, 2009 12:49 PM in response to Soundproofing

Thanks folks. I actually have neighbors living above us, so I doubt they'd let me rip up their floors for cork! The contractors have proposed ripping out the existing sheetrock, putting in very dense insulation then using a noise absorbent "sheetrock" to finish the ceiling off. I was assured that this would make my place like a tomb but it comes at a rather steep cost, upwards of $20k for a fairly small place, but it sounds like my best option here. My sanity is at risk!!!

Posted by: ralphus999 at January 24, 2009 5:18 PM in response to Soundproofing

The best place to find the answer is through the recording studio searches.

Posted by: Iknow at January 24, 2009 8:14 PM in response to Soundproofing

http://www.quietsolution.com/html/quietrock.html

Quietrock is one of the better sound proof wall boards, most of it is fire rated as well.

Posted by: FenFen at January 25, 2009 11:40 AM in response to Soundproofing

when you hang the new ceiling, you will want to hang it on joists that are set between and a couple of inches below the joists for the floor above. This can be achieved through traditional materials such as wood or by hanging a steel grid on which to apply drywall. i've seen drawings of the way to stagger and set wood joists on the 'net. I am sorry, I can't recall the site.

Steve
the tinkers wagon home repairs
347-813-9635

Posted by: thetinkerswagon at January 27, 2009 11:54 AM in response to Soundproofing

if you want it to be done really well i would go the decoupling route. ALso put down some rugs where the kids move around. I'm in the same situation i want the garden floor to be quiet from footsteps. Renovated the garden floor but the ceilings were low so we didn't do much except a layer of sound board which didn't do nearly enough for my tastes.

Going to one day rip up my floor and look into if its possible to decouple from up here because on this parlour floor the ceilings are very high so i don't have to worry about losing a few inches

Posted by: 11211 at January 27, 2009 4:07 PM in response to Soundproofing

Unfortunately, footfall noise is the most difficult to deal with. The direct impact injects a great deal of energy into a small area. This easily overwhelms most isolation systems and products. This is distinctly different from isolating airborne noise. An analogy is surviving a rifle vs. shotgun. Footfall = rifle. A TV set = shotgun.

Thin mats and pads don’t offer much relief at all. Again, very easily overwhelmed by the impact energy of a footstep. Their success is limited to the high frequencies (low energy) and not the more bothersome thumping low frequencies.

Here’s an article with data and graphics that explains the footfall noise problem in detail. http://www.soundproofingcompany.com/index.php?/solutions/neighbor_noise/neighbor_noise_ceilings

I am affiliated with this company, so let me say that for full disclosure.

Given that 95% of the time the problem can only be dealt with from below, generally the best results are obtained when you:

Remove the existing ceiling
Apply mass and damping to the underside of the subfloor
Install simple run of the mill R19 fiberglass insulation
Decouple the new ceiling drywall from the old joists
Install new drywall.

This is a multi-faceted approach that works best, and is a good bang for the buck. Exotic insulation does no better than R19. Lab proven fact. You can assemble your own “soundproof drywall” and have better, far less expensive results. Another lab-proven fact.

If you focus on the fundamentals, you can really improve things a great deal.

Posted by: Ted White at January 29, 2009 4:19 PM in response to Soundproofing