On Jan 3, 9:07*am, "TKM" wrote:
What kind of insulation materials should I use to insulate the hot-air pipes
and ceiling in *a furnace room?

The house is about 5 years old with 6 inches of blown-in cellulose
insulation in the walls and ceilings. *The furnace room is on the second
floor and has a finished drywall ceiling and walls. *But the room is very
warm during the winter and snow on the roof above the furnace room melts
before the snow on the rest of the roof.

I've sealed the furnace pipe joints with mastic to stop hot-air leaks; but
now I'd like to wrap the pipes with insulation and add a layer of ceiling
insulation inside the room and maybe the outside wall too.

Is there a return in that room so that can recover some of the wasted heat, is it a unit that uses outside air for combustion. How can you have 6" of wall insulation in 2x4 construction. 6" in the attic is only maybe R 21. I dont know where you live but R 21 is not much. My fire code specifys 5/8 drywall firecode x for any furnace room for the interior finish.