How do you insulate the top of a walled dead space that was made for an insert fireplace's pipe run?
Situation is this: rental home, vaulted high ceilings in the living room which has a an insert metal fireplace. The insert fireplace in the living room has a three walls built around it that run from the floor to the top of the vaulted ceiling. The walls around the fireplace form basically an uninsulated box [...]