I am trying to determine an STC rating between some apartment units that are on the upper floor with in an unvented attic. This is an existing condition where the demising walls go to the bottom of the ceiling of the unvented attic. The attic had blown in insulation above the ceiling that has been removed and now a new rigid insulation is being placed ontop top of the roof deck as part of correcting an improper design. The ceilings of the units will consist of 5/8" gyp board attached to resilent channels that are attached to the roof trusses. Thus I would have a horizontal assembly with a certain STC rating and will construct some type of vertical partition at the common wall between the units. We are trying to determine how to cost effectively construct this parition and also determine the STC rating of the overall assembly.
US Gypsum , "acoustic" ceiling tile mfrs, and the fiberglass insulation folks used to have some very useful information about STC ratings of various wall and ceiling constructions, as well as recommended ratings and systems for various applications. Like executive offices and conference rooms, and floors between apartments, etc.
Also Architectural Graphics Standards
Thnks, Tmoose, I contacted their tech support, that's where the detail came from in my post. I have a feeling it's going to be one of those things that noone gets back to me.
Try the calculator. I ran some numbers, and they seem reasonable. I am assuming you do not know the frequency range you are wanting to attenuate, which in a use specific application and would be important but for just general noise this should be adequate.
