Re: Ferry Farm. The truss was designed as a "replica " of the truss found in Historic Kenmore, the 18th century home of George Washington's sister.
Kenmore I'm not sure if that truss uses a thru tenon but I suspect not. The thru tenon that we used was just a bit of artistic license. The wedges are not bearing any significant load, just limiting sag in the tie beam. The roof forces are resolved at the foot of the King post where the struts bear. The tie beam is joined with an English tying joint. The posts are tenoned into the tie and the tie has a dovetail cog which engages the continuous (albeit scarfed) wall plate. The check you saw on the thru tenon showed up almost immediately but is not a huge structural concern as this joint isn't holding the building together. We are hoping to do another pavilion almost identical to the FF version this spring. Keep an eye out in Scantlings or on the web site. I believe it will be in northern VA. If you have any other questions about the FF frame, let me know as I have the plans and worked with Grigg Mullen and Bob Smith on the joinery decisions.
