Climate Zone 4 – I am trying to finalize the details for insulating the floor/ceiling between 2 unconditioned spaces (garage/root cellar) and the conditioned spaces above them and a space conditioned to a temperature below the design temp of the house (wine cellar at 55 degrees).

Garage – Having lived in a house with a bedroom above a garage, I know how important it is too get this right.  The family room is directly above the garage.  The floor assembly between the 2 rooms is 1 3/4 x 9 1/2 lvl’s as joists with 3/4″ Advantech subfloor.  There are no mechanicals running through the assembly.  The rim joist will be insulated with 2″ of Lapolla 4G ccsf.  I was planning doing the same for the bottom-side of the subfloor.  To limit the thermal bridging through the lvl’s, I was going to add 2″ of foil or fiber faced Polyiso covered with 5/8″ sheetrock.  From an air/vapor control viewpoint, I believe I should be fine if I left it at that.  What I am still debating is what to place between the lvl’s.  I am thinking either DP cellulose or Rockwool.  I will have 7 1/2″ of space to fill.  Thoughts?

Root Cellar – In the NE corner of the house, passively ventilated, no subfloor insulation, 4 walls of concrete, below a bedroom with floor assembly of 11 7/8″ TJI’s and 3/4″ Advantech subfloor.  I was planning on insulating this space in a similar manner to the garage, just with more stuffing in the joist bays.

Wine cellar – same floor assembly as the root cellar, but much lower delta T with the conditioned space above.  I am wondering if I can get away with just the ccsf and the Polyiso and avoid any additional insulation in the joist bays?

Thanks,
Jonathan