The bottom’s are 4×6 and the posts are 4×4. These were leftovers from the shop build that have been sitting in the corner for quite a while. They are joined with dado’s, glue and a few 4″ deck screws.
Theses are fairly heavy and hold the doors really well. I could have just as easily make them from 2×4’s glued and screwed together. It would have taken three or four 2×4’s – about $10.
I hold the doors with clamps at the top and that’s plenty of support. If needed to, I could move them to the ends of the door and clamp the bottoms as well. I could also hold full sheets of plywood this way.
I thought about drilling holes so I could put dowels in to raise the door up, but I don’t think it’s needed. If I want the doors higher, I can cut a couple of blocks and clamp them to the posts.