Hi all. I've been watching this forum for a long time as a result of my google search hits and finally decided to join and ask some of my own questions directly. I'm in the process of designing and building a barn (for myself) with a mid-span beam roof system which will support common 2x rafters. While working out my scarf joint locations I've been wondering why you never see beams at the top of a post, joined to the post faces instead of set on top, similarly to beams part way up (such as with floor support beams). I have seen a photo of such a system but I'm left wondering if the bending moment would be simply translated through the post and into the adjacent timber, which would move the problem from the eliminated scarf joint to the spline or tenons at the post (where there would conceivably be more bending stress).

This would be attractive to me because I could order and handle shorter timbers and eliminate the scarf joints altogether; all good things for me as I'm an amateur on a budget that allows for limited equipment support.

A wordy first post that could benefit from pictures I know, but I haven't yet figured out how to add pictures (working on it).

My apologies if this has been covered in a previous post, I did a history search but didn't find anything that quite addressed this.