Roadyy - generally it is surprisingly dry here. The wood floor sits on top of 3-4" of gravel and the barn is located on a high spot that is quite dry. During the winter, we will plow the snow away from the barn as well so there shouldn't be much moisture seeping in due to snow melt. My neighbour has had the same set-up now for about 5 years and has had no moisture at all. If anything, our building is positioned even a little better than theirs with respect to the slope and lay of the land.
That said, there is a slight slope E to W toward the barn from the driveway, but it also slopes even more N to S. If anything, we may see a bit of moisture on the SE corner where it will remain gravel only until we do something else. I am waiting on a good rain to see exactly where the water will flow. If necessary, we will add some landscape features / weeping tiles to facilitate drainage.
Quick question. What do you recommend for sealing the wood on the stalls and kick wall. Is it even worth sealing it? I don't want anything toxic, but would like something that may help the manure wash off the walls a little easier of need be. Thoughts?