Japanese Tie Beam to Plate Joinery

I've been wondering what the most effective joint for joining round tie beams to the plate would be. I'm guessing a cog of some kind. It seems like a dovetail would be putting a lot of dependence on a very small amount of wood. I could drop the ties into the posts, but I would rather not. There's a few options shown in Engel's book.

Thanks,
Brad

Hi Brad,

thanks for posting up the question. The three versions shown in Engel's book comprise the standard choices. As Engel and many others have noted, the housed dovetail is a weak option. If one goes with the housed dovetail then a reinforcing tie bolt is required to tie the beam horizontally to the plate.

The cogged lap joint is the best option, if you're looking for structural effectiveness. There are a couple of different versions besides the one shown in Engel's book, however what he does show is fine. Engel does however mis-name the cogged lap joint illustrated - it is not, as he calls it, a variation on kyōro gake, it has its own name and is called tsuki-watari ago

~Chris