Drywall or not?
I am building a house with cathedral ceiling, which will be finish with some pine wooden plank. I remember reading in GBA the necessity to have plastered drywall underneath the wooden plank so it can serve as an air barrier.
In my case I will have some roxul insolation then polyisoyanurate panel then fur strip and then the wood plank, my question is do I still need to have plastered drywall under the wood plank or is the polyiso panel will also act as the air barrier therefore drywall is not necessary.
Thank you in advance
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