STC rating for urethane foam and shotcrete

I am looking to see if any one can tell me about the STC rating with 2'' of 2lb high density urethane foam and 4'' of shotcrete for the outer shell of a studio I am looking at building?

so a single concrete wall with 2" of foam insulation on it? http://www.nrc-cnrc.gc.ca/eng/ibp/irc/c ... s-n13.html

Somewhere in the area of 45 to 50....depending on what the surface is the shotcrete will be placed to. Meaning, you have an existing structure that this will be (shotcrete) placed on, so we would have to know the properties of that as well. And since everything matters, will the ceiling/roof be treated in the same manner?

This building will be a single cast building . The only one of its kind. I plan on pouring a footing and separating every floor in the building with isolation joints so know floor will be connected to another. This building will have a rebar armature and I will stretch fabric over it. I will then go in and spray 2'' to 3'' of high density foam attach rebar hangers and run a rebar grid in 10'' squares threw out the structure . I will then shoot on 4'' to 6'' of 10,000 psi shotcrete from the inside over the foam. I am wondering if anybody has an idea what the STC rating might be on this. This will be one large structure and every room in it will be separated from the shell. I would also like to know is this would be good for the inside walls minus the shotcrete for separating my board room from the recording booths. I also am wondering for in the studio if it would be better to use a open cell foam witch has a very high NRC rating? Never built a recording studio so any info would be good.

Remembering the shotcrete is a process, not a product, your answer will come from looking into concrete of the same thickness. In that respect, the thicker the wall being placed, the better the overall STC and Transmission loss values will be. The Urethane is more for the thermal envelop I assume since you would specifically not want to have this exposed, even that assumes that local code would allow this type of practice. Typically you have to install sheathing of some type after the insulation which requires a framed wall assembly. Could we see the design sheets on this project?

you say each room is separate? this is due to the foam shells? presumably before all this is done you will have extremely detailed plans on the HVAC, wiring, fire control, plumbing, etc? and engineering down to the last pound to ensure the foam can support and have the resilience to decouple correctly? just asking as there are some pretty complex floating room studios on various isolator types and it's not trivial and will likely cost some serious $$$ (as in millions...)