Whatever route you go, be sure to use exterior grade fasteners - hot dipped galvanized or stainless steel or some of the new ceramic coatings. My contractor used "bright finished nails" and 2 years later I can see everyone of them thru the paint.
I will echo others advise on pest-proof materials. Unless you are committed to the maintenance, it's a forever battle with wood, between the woodpeckers & carpenter bees. Here in Ohio, the bees have no problem drilling into a horizontal wood ceiling.
As long as you're willing to put in the work, I agree nothing looks better than real wood. But you should also be aware of the maintenance & time requirements to keep it that way.
Day-M! That's purdy! My Grandad's old home (built in 1913) had the old style tongue and groove in the ceiling of the covered porch, and it was still good when they moved it in the early '60's. Yours would look better with a porch swing, though!
I used Sikkens Cetol Log and Siding in Butternut on the ceiling. The color chip looks light but it comes out quite dark, as you see. All boards were pre-finished flat on sawhorses. I did one coat on the back side and then 2 on the front. Those boards are double wide, so they look like 1x4's but are actually 1x8's with a groove routed in the center to visually match. The ends were also T&G which helps keep everything tight and un-warped. That was almost 5 yrs ago and they still look like new, but of course they are not really exposed in a ceiling.
I cathedrealed all the ceilings in my house and put the same 1x8 bead side up and have been wanting to do the soffits and have been research finishes for outside and have heard nothing but good things about Sikkens you just locked in. inside I did 1 coat Minwax Ipswitch Pine and 4 coats laquer . Wood Rules.:number1::drink:
I thought I should update this thread. I finished the porch ceiling on our cabin this weekend. I wound up going with exterior plywood bead board siding. Thanks to all who provided guidance.
Old houses I have worked on and some new, used doug fir beaded boards about 3x5/8. Clear straight grain. Very nice material. Might not be available these days.