We just purchased a tiny vertical log cottage in NJ and are attempting to retain the 1937 period look of raw open ceiling, (3×6 roof rafters on 24″ centers with tongue & groove roof sheathing). The asphalt roof is in need of replacement, opening the possibility of insulating the roof above the sheathing using foam insulation, covered by plywood sheathing and then a new asphalt roof. This would retain the appearance and heat in winter.
Does anyone know if this is a bad practice regarding condensation between the original roof sheathing and the foam insulation, which would cause roof rot?
We have talked to a roofer we previously worked with, and he has used it this way recently on a cottage of his own, but we still have concerns.