Will, You are right that lowering the tie beam has placed a bending moment on the post centered at the tie beam location which did not exist in the original design, but this bending moment is much smaller than moment centered at the base of the post, which is resisted by the tie beam tension. I'm only plannin to lower the tie beam a couple feet.
That said, you guys have got me thinking about this and I'm now leaning toward adding a ridge beam and posts that extend from the middle of each tie beam up to ridge. This would also allow me to add bracing to resist racking of roof.
I will get someone to check my design, too.
I'm trying to do this with the materials I have on hand.
Keep the comments coming, this really helping me. I've also read all of the Ted Benson and Jack Sobon books my library had to offer.
-Dave
