Issue has been fixed. However, I am trying to learn the reasoning and why it happened. I have five years of roofing experience but feel like i learn and understand better if i know why.
There was a cathedral ceiling in the house. Roof and attic space are completely cut off from said room. No soffit vents or ridge vents on previous roof. Previous roof had architectural shingles and asphalt felt. No issues. No leaks.
New roof was installed with architectural shingles and synthetic felt. The roof then began to show signs of sweating on the ceiling. Installed soffit vents and ridge vents, solved the issue.
My question is that once the shingles are installed then you have a vapor barrier. But the only difference between new and old roof was installation of synthetic instead of asphalt felt. Does the permeability of the felt play a role once the shingles are installed? I