In every vaulted ceiling ive ever seen or worked on it still has had a significant air gap between the insulation and the roof and it was still vented with roof and soffit vents. Also the areas that tend to leak before any other part of the roof because it is hard to vent enough air through such a small space.
And nearly every roof ive worked on that had curled shingles lacked proper roof ventilation. That isn't direct evidence, but ive never seen curled shingles on a well ventilated roof either and the only common factor in curled shingles is heat buildup in the attic/roof cavity.
And nearly every roof ive worked on that had curled shingles lacked proper roof ventilation. That isn't direct evidence, but ive never seen curled shingles on a well ventilated roof either and the only common factor in curled shingles is heat buildup in the attic/roof cavity.