newly constructed vaulted ceiling in kitchen open to a family room. condensation or weeping occurs when hot. there's no ventilation, typical vaulted ceiling with rafters, r30 batt insulation and 1/2 drywall. black asphalt roof. we added ceiling fan to circulate the air and it seemed to have worked during last summer but it weeped again, this time from the ridge beam. spoken with several contractors and original structural engineer. no one seems to know why. some say it's the ac vents but it has happened on hot days without ac. we repaired the damage dry wall and added the ceiling fans (about 6K) and today the problem happened again. sorry for long post, any ideas, we don't know the cause