Should I fill the unvented soffits with foam?
We have an outbuilding that’s about 12 x 13 that we want to turn into year round writing / guest room.
It has a basement where well equipment is located. We’ve sealed and insulated the ceiling and the floor joist bays above the foundation and covered with 5/8ths wallboard. With a tiny heater that comes on intermittently in the cold weather, the basement stays about 42deg F so the pump doesn’t freeze.
We plan to improve the ventilation for the warm months when some condensation occurs.
Inside we’re insulating the roof and walls. The roof with XPS panels glued in place and the spaces filled with Great Stuff spray foam. The walls will have 1″ XPS panels mounted 1″ away from the backside of the pine siding which is nailed to the studs with no sheath in between. I am thinking of filling the soffits with foam. Is there a significant downside to doing this? Should they be vented (I have these 3″ round copper vents.) or is OK not to!
Thank you v much,
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