With regards to traditional attic insulation, assuming an unconditioned attic above 2nd level, I know that it is highly recommended to properly air seal and insulate the attic floor and not between the roof rafters for several reasons. So in a 1.5 story house or cape, where there is an unfinished attic area behind the knee walls, why does many “experts” and building scientists stat that the ideal way to insulate these areas is to:
insulate the knee wall and floor (which I agree and understand)
and insulate between the roof rafters in the sloped ceiling (doesn’t this contradict the above? By insulating the knee wall and floor, you’ve in essence, have separated the conditioned living space with the unconditioned attic area behind the knee wall. I would’ve thought that you wouldn’t need to insulate between the roof rafters in these areas.
Any thoughts would be highly appreciated as half the homes in inspect with such areas have insulation between the roof rafters, and I wouldn’t want to call it out if that is the “preferred” method of insulating these areas.