We are looking for a good low maintainance soffit material for a contemporary addition with mostly 6 foot wide soffits. The broad second floor shed roof shades south-facing walls that have a number of windows.
The total soffit area is about 420 sq. ft.
Joist spacing is 24 in.
I plan to attach the soffit directly to the joists, sloping down 1.25 in/ft.
I have seen nice pictures of smooth, uniform, wide soffits, but how are they made?
Painted plywood would work at reasonable cost, but painting, maintenance, and potential joint movements are negatives.
Standard aluminum and vinyl soffits are easy, low maintenance, and inexpensive, but large areas of the highly visible corrugations would look out of place.
Solid PVC (like Azek) would look good, but it is expensive and might require additional support over the 24 in. spans. (Hide the screw heads?)