I have a single story home that has 30 recessed ceiling lights, of which 15 were recently added and rated as IC. The remaining lights may or may not be IC
rated. Without rummaging around open joists to find out, the insulation company has offered to install a 12" sheet metal sleeve, similar to stove piping, around the lights to keep the insulation away from the can. Is this an acceptable practice ? And should I do it for all of the lights since they have to work near all of the lights anyway ? Thanks for your input.
Yes, the metal sleeves are a standard way of solving this problem. Although you don't have to install the sleeves around the IC rated lights, the bulbs will last longer if you do. Insulating over IC lights is safe but it raises the operating temperature in the fixture substantially. The higher temperature reduces bulb life (particullarly with incandescent bulbs). On the other hand, more heat is lost to the attic around the sleeves. Pick your poison.