My client has a house built in the 1970s with cathedral ceilings, a shallow (2 in 12) roof, 2x12 rafters, and T&G pine ceiling. The ceiling was insulated (looks like R-38 faced batts), but there is neither ridge nor soffet venting. The owner had a membrane roof put on about 2 years ago and now wants to remodel. I am concerned about an unvented roof with a relatively "leaky" ceiling-- won't there be issues with moist air getting into rafter space and condensing on the underside of the roof deck? Unfortunately, there is intermittent blocking between the 2x12 rafter bays, and it has a boxed soffet as well. So we don't have easy access from the top, bottom, or sides. He lives 100 yards from the ocean in climate zone 4 (mendocino coast). Any help is appreciated.