We have a cottage at the lake with a modified A-frame roof and cathedral ceiling. We use it year round using electric heat. We have a real problem with condensation in the spring. There is water leaking from the beams, fireplace opening and light fixtures. The roof was fibreglass insulation and vapor barrier. We have installed 2 whirly-birds to improve circulation. What else can we do to correct this problem?
Answer:
First you get rid of the whirly birds because they ventilate only between the rafters that they span. What you need is good soffit ventilation and a baffled ridge vent that stretches from gable to gable on the very peak of the roof. That ventilates between all the rafters and if there is good air from soffit to ridge vent above the insulation, you have no reason to put up with condensation.