I've learned that the half-dovetail-shouldered-wedged-through-mortise and tenon joint is a strong one. And I am thinking about building a small barn following the "high posted cape" design shown in one of the popular timber framing books.

Looking at the tie beam joint for this "tie below plate" design which involves a half dovetail tenon joint, I noticed that the wall plates require a mortise that is cut into the half dovetail tie beam joint. I am concerned that it will weaken this strong tie beam joint. It also looks that there really isn't that much room to peg the wall plates.

Do you think that the wall plate mortise (and peg holes) cut into the half dovetail joint weaken it?

Here is a pic of the joinery in question. Note that this pic shows a smaller wall plate (almost a "girt"?), but the design requires a larger 7x7 or 8x8 "wall plate" (which would require a larger mortise).



Thanks for your time.