I did seal the ends of the 8x8 kingpost, and the 8 foot summerbeam, with wax, to minimize splitting.
That main summerbeam was so heavy that I decided I would put up with some cracks, in order to get as much water weight out as possible, so I didn't seal it. As of 2 weeks ago it was hardly splitting at all. Anyway, the cabin is supposed to be "rustic looking" so I don't mind a few cracks.
The main favor I did myself was I got a winter cut on these trees. I cut them in March when the sap was down.
