You need only borrow an old idea, and add a few new ones to make good use of your vertical boarding.
Many barns hereabouts (and they’re always better for it + it is part of how they survive after the boarding begins to fail) were boarded with a thin vertical batten against the frame beneath the butt joints – commonly known as reverse board an batten or RB&B – this provides that “drain plane” Joel was speaking of, but more importantly, it separates the sometimes wet and leaking boarding from the frame allowing everything to readily dry after a rain.
I commonly enclose barns with this method and have come to add only one improvement, this by attaching a hunk of “Roll Vent” betwixt the battens against the sills,
this void would historically tend to fill with hay and chaff and spiderwebs, all the stuff of everyday, and these accumulations would sometimes act as a sponge, retard evaporation and hold moisture against the sill. I remove the breathable fabric cover from the roll vent, cut it to the full size of the space between the battens, then refold the fabric over the ends of the matrix top and bottom, this to keep bugs from dragging their stuff up into the void and to keep gravity and time from clogging it from above.
Add some type of high tech building fabric (overlapped from above to shed water) and I would not be unwilling to reuse even somewhat used up boarding.
Be your best
