I’ve been pondering the best way to adequately ventilate a vaulted ceiling of a small housing unit I’m making, while still getting a decent amount of insulation in there. I was planning on putting a 1 1/2” vent hole on each end of the 2×6 rafter bays and putting in R-19 insulation, but maybe this doesn’t allow for enough airspace for ventilation. While thinking about all of this I thought of the 2×4 stud bays in the walls, filled with insulation, and how this is essentially an unvented assembly, but we don’t seem to have a huge issue with condensation and rot in a typical insulated 2×4 wall. I’m just a stupid carpenter, could perhaps a building scientist explain why we need to vent ceilings and not walls? I’d like to hear from others how they vent a vaulted ceiling as well.