"sid" wrote in message
...
Most of the basement is lined with Owens Pink Foam-board. If I use
this foam-board to insulate the wall of the furnace room, can I leave
it exposed ? Do I need to finish the walls ?

Thanks

Building code says it should be covered with gypsum board or equal. The
board is made from a fire retarding material, but in the presence of a
flame it will burn. Given that it is a furnace room, I'd cover it.