We are in the process of an energy-focused renovation (Climate Zone 4, Manhattan KS) and I am looking for advice in selecting an appropriate underlayment. Our planned roof stack-up is:
5″ closed-cell spray foam against the sheathing, encapsulating the 2×4 roof joists
1×4 counter battens (laid flat and secured through OSB to the roof joists)
Plastic barrel tile, fastened to the battens (Quarrix or Brava)
This stack-up gives us a ventilation space between the tile and underlayment, and we will have vents at the hips (this is a pyramidal hipped roof) and the eaves.
My primary question is what underlayment would be most appropriate, long lasting, and provide adequate drying for the OSB layer?
My thanks for any advice you can offer.
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