To keep fiberglass batts from blocking airflow rafter baffles should be.
Cellulose insulation vaulted ceiling.
In a vaulted ceiling however the only fresh air route lies between the insulation and the underside of the roof deck.
Cathedral vaulted ceilings fix upgrading to cellulose insulation cathedral ceilings can be a real nightmare for energy efficiency because first of all you have all of that space that your heating that you can t feel.
This makes it much more difficult for air to move through the insulation.