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.
Second cellulose has a stated r value of 3 8 per inch as compared to 3 2 for commonly used batts and 2 2 for blown fiberglass.
Now we re going to do is blow cellulose in this hose all the way down to the cathedral ceiling bays and we have air baffles all the way down to the bottom so that air from the vents could get up and out the ridge vent.