Mike Walsh
2/13/2015
I am finishing a 14x40 barn/shed style cabin with OSB board on the rafters then a metal roof. I heat the cabin with a wood burner and now I am developing condensation on the OSB board under my batting insulation. I foamed up the ridge vent to make the structure more air tight/mouse proof/bat proof and didnt put a plastic vapor barrier over the batting, thinking the paper moisture barrier on the insulation would be sufficient. Does anyone have any recommendations for a fix? Would pulling the foam out and putting up a plastic moisture barrier solve my problems? Or would just a vapor barrier work. Please help !!
Eric Novotny
An informed customer is the Best Customer!
2/14/2015
You are going to have to either vent the roof or insulate it more significantly and to keep the condensation from forming. Can we get some more pictures of how the insulation schedule was done.
Mike Walsh
2/14/2015
I have batting insulation that i will be putting 1'' pine boards over.
Eric Novotny
An informed customer is the Best Customer!
2/15/2015
The paper is far from airtight. That being the case, moisture is making it up to the decking and condensing. You should cover that framing with some rigid foam or something. I would have liked to have seen some sort of integrated vent space as well to control the condensation potential. Perhaps some rigid foam over the framing prior to drywall?

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