Can I use cement board or limp mass barriers with the Iso-Wall system?
Yes, you can use more massive wallboard or additional layers of extra mass with the Iso-Wall system. Be sure to place the resilient channel more closely together to provide the extra weight support needed, if you do this. It is important to note, however, that the individual sound blocking abilities of different materials do not simply add to one another. For example, a layer of mass-loaded vinyl may have an independent STC rating of 30dB and your existing wall may also have an independent STC rating of 30dB, but when put together you will NOT achieve an STC of 60dB. Doubling the mass of a wall will typically increase the soundblocking power by 2 to 4dB. So, for the previous example the resulting STC would most likely fall between 32 and 34dB.
