I have been reading online about high performing STC wall noise control products. How much added noise control do I get when add them to my RSIC-1 ceiling system?
The short answer is, It has not been fully tested. The current belief is that if something works on a wall, it must work on a ceiling. Unfortunately in the world of acoustics, that logic does not always apply. There are conflicting reports online and published that may be addressed here.
Lets start with the basics of noise. Mass, Resiliency and absorption controls noise. This is an oversimplification of noise control.The best systems apply all 3 of these methods.
Walls are unique in the way that the gypsum board is held compared to the how the noise acts on the gypsum board. Typically the weight of the gypsum board is being held up, and the noise is applied to the broad side of the board. Imagine setting a piece of gypsum board on end then holding it up with 1 finger. That is totally possible. Now move that gypsum board slightly back and forth. This is how noise (vibrations) are applied to the gypsum board on a wall. Because the weight is being balanced, the amount of isolation/decoupling needed is low. All the noise control product has to do is manage the light back and forth of the gypsum board. This is why you see some success with RC-1 channel, Visco elastic products, Visco elastic gypsum boards, and isolation clips. The performances here have some large variables from STC 46 to 64. There is a large range of wall systems that can be effective for your projects.
Ceilings are different. Lets look at the same type of example we used above. Take the gypsum board that was resting all its weight on the ground (edge), and now hold it over your head. Unless you are quite the workout buff, this is fairly hard to do. Now imagine the degree of energy needed to hold and move that same board. Gravity has changed how that same piece of gypsum board reacts to the same/similar energy. That gypsum board that you so easily moved with one finger in our wall example, now is an immovable object, not really but its very heavy. All the weight is loaded on the same plane that the noise is trying to pass through. The entire weight of the ceiling has to be fully decoupled and isolated for any chance at a good acoustical result. This is where we see some separation in products. If you were to rate the options, best first: 1. Spring isolation 2.Rubber isolation 3. Channel Isolation 4.Mass and or Visco elastic products. The mass and visco elastic products are listed even here, only due to a lack of real test data for those products on ceilings. More testing is needed on the visco products to warrant a true placement in this short evaluation. By no means am I discounting the visco elastic products, only stating that there needs to be more testing.
Isolation clips with mass is currently the least expensive, highest performing option for a successful noise control ceiling system. The implementation of increased mass along with the correct isolation system, whether it be a rubber, or spring based isolation is where you see the best gains in acoustical performance.
I am sure there are plenty of arguments to this online. Here at PAC we rely on test data. When new test data is available we can revisit this.