Commercial Gypcrete and Vibration Dampening

troy_8

Try asking an applicator about using acoustimat under the pour. It really works well at isolating the gypsum floor from the subfloor. That greatly reduces sound transmition.

Chap

Commercial Gypcrete Application and Vibration Dampening

Apparently there are many codes that go into commercial buildings. I am currently battling with an in-floor gypcrete system that will have livable space below it. There are fire, sound, and vibration codes to overcome between floors. The sound and the fire seem to be no problem with the gypcrete, the flooring, and the double 5/8" rock on the ceilings. But the 1.5" of gypcrete makes the vibration dampening an issue. Apparently the more gypcrete you have the more vibration dampening becomes a problem. Im wondering if anyone has experience with, or found solutions to this problem. I am currently looking at "resilient channels" as a possible solution to the problem, but am having a hard time finding documented cases in a gypcrete application. Any thaughts or alternative ideas are appreciated.

Thanks

Chap

Acoustimat

The problem with acoustimat is that we cant staple the tubing directly to the subfloor. Wire mesh needs to be laid down and tied to, or some variation. I am looking for a product that we can staple directly to the subfloor.

Thanks

Mike T., Swampeast MO

While I'm not sure about the motives of the source, here's an interesting document regarding the use of resilient channels--supposedly the failure rate is 90%!

Since this is a commercial application with code that mentions both sound and vibration, the obvious concern is sub-harmonic resonance that can be induced by things like footfalls and machinery that must be assumed can become slightly unbalanced. If this is a wood floor system, personally I would use something other than gypcrete as [I think] the 1.5" thickness would add to the potential for resonance in spaces designed to be large and open. I believe that the gyp would prove difficult to isolate.

Tom Manton

Mike T

Why would you need to isolate the gypcrete, wouldn't it act as a dampener itself ( mass v. dampening ). I don't have anything to support this theory, just in the multi level condos I've worked on it seem to lower the harmonic resonance of the building.

Drew_2

Vibration/Sound

Not sure what you are tring to achive when you speak of vibration problems with gypcrete. Give us more information.
IIC, STC?

Chap

Necessary Ratings

Here are the ratings we are trying to overcome. I appreciate the info on the resilient channel.


One hour fire rated floor/ceiling assembly
STC lab sound rating of 50 or STC field sound rating of 45
IIC lab impact rating of 50 or IIC field impact rating of 50

The assembly must have these components:
Gypcrete
OSB floor sheathing
Min. 9 1/2" I Joists
Res. Channel
5/8x or 5/8c drywall


I have also talked with the gypcrete guy who says Fracture Gaurd 5000 can also help in sound and vibration dampening but I cant find any case studies on it.

Thanks