I'm trying to figure out how to increase the ventilation that comes from the soffit vents to the roof peak on the north side of the house and need some ideas. I am getting moisture above the air channels on that side only. I can see where the black mold is starting from just above the air channels to the peak. There is no black mold on the roof deck that is covered by the air channel which leads me to believe the air flow there is sufficient to keep it dry.
The front side is fine, I believe because it catches sun most of the day and that side also has a deck which warms considerably and I believe promotes the flow of air up through the soffit.
Both sides are insulated the same and there is no difference in room moisture below which is why I am thinking it is a north - south thing. I am thinking about placing 1/2" foil faced foam board across the roof rafters to enclose the bays and see if that encourages the air flow to keep them dry. Any other better ideas?