I have a small barn, about 16 by 12 that is board and batten. The
boards are random width rough sawn, between 8 inches and 12 inches
wide. The battens are 2 inches wide and nailed to the boards (there
are not studs behind every batten). There are cats between studs at
the four foot mark.
This barn is the driest one I have, never any water getting in
regardless of the weather. This is partly because the rough sawn
lumber swells a bit with humidity and seals tighter. The same thing
happens with the cedar shake roof. You can se daylight through some of
the pinholes through it, but when it rains, it seals up tight.