Here's the situation:
1938 Seattle house, with years of owners putting their "touches" on it. One touch included finishing the attic to make it a livable space. This meant putting fiberglass insulation in the rafter bays (2x4 framing) and sheetrocking over it. Don't know if the insulation has a vapor barrier or kraft paper facing.
We live in Seattle, in a 4C maritime climate. This means relatively dry and warm (not usually very hot) summers, and cool damp winters.
On warm dry days, even weeks of warm dry weather, we'll come home after a full day out or a vacation to a humid, musty smelling house. I was describing this to my contractor brother-in-law, and he asked if the roof is vented. It is not.
A recent house inspector confirmed this, and said this is likely the reason why we have the dampness and smell--with the stacking effect in the house, the warm damp air has no place to go.
(BTW, we have a crawl space, but it is clean and dry with proper vapor barrier, and the inspector said that it is not the problem.)
Here's the problem: we have no eaves or soffits, and no actual drip edges off this part of the roof because one side connects directly to a flat roof which we think was added to cover in a back porch to form a hallway and space for what is now the bathroom and a small bedroom, and the other connects to the front porch roof and the roof of an addition.
So: how can we improve ventilation? Completely reframing (and raising) the roof is one expensive option, but is there a compromise option? Would a few metal roof vents make a difference, even if there are no soffit vents nor, I assume, any space between the insulation and the roof sheathing? Can we avoid pulling all the drywall down?
Thanks for your input!