California inspectors and contractors:
what is your call on "IC" cans in the building envelope that requires insulation,
ie; older house without insulation installs 2 cans in the kitchen. any other ref. besides t-24 150(k)4?-thanks--dave

On the Contractor side:

From the get go, plan to use IC on any top floor, or unit seperation. (Condos or Apartments that might become condo's, odds are some has some secret plan to do just that.) Irreguardless of insulation or not. (If there's not any now, there will be!)

On of my first questions walking a job is "Is there any insulation, and where? Is there any plan to have insulation anywhere else? Are you sure?"

Some places will accept Non-IC boxed out from insulation, to eliminate contact with the insulation. 3-6" But its a call to your inspector...

Fire rating is diffrent ball of wax... But wise to note as well in the same topic.

Here in NJ the building insp. are requiring IC cans in any area that doesn't have a floor above it. This way you can insulate up to the can and not loose heat through the can.

Harold