Unvented roof — vaulted ceilings — moisture, rot, etc.
Im hoping someone can steer me in the right direction for an issue Im having with my current roof.
As best I can describe here is the situation
Full home remodel completed in 2015 including 2nd story addition and brand new roof.
Home is in Southern California about a mile or so from the beach
Vaulted Ceilings exist in every bedroom, however the problem seems to be localized to one side of the house where there is not attic space, no venting.
Canned lights exist in each room, they are just standard cans IE they are NOT fully enclosed/sealed
Roof is 2×6 rafters, 1/2″ Plywood, roughly 4″ rigid foam insulation and standard black shingles and roofing paper. Again there are eaves but no venting anywhere for this portion of the roof.
The original problem started when I saw some brown spots in the drywall near the ridge. That led to a a patch fix of about 4 feet of plywood that was completely rottted out wet. less than a year later the same issue is occuring again but it seems to be getting worse. Ive had an environmental inspection and while Im awaiting final mold results, the humidty levels in the small amount of cavity in the roof were over 90%. (Standard humidity outside is roughtly 40-50% and inside the normal air is roughly the same)
Ive read about the possible need for ridge venting and eave venting but Im not sure what the right solution is here. I know you can also try to seal anywhere moisture can get into the roof cavity but it would seem tricky considering the existence of the canned lights and from what I have read, water vapor can travel through the drywall.
Any thoughts here are much appreciated as I search for a solution. Attached are pictures of the damage as well as picture of the eaves.
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