lapped dovetail bracing for an anchorbeam?

[slackwaterfarms]

Hi All!

I had a couple quick questions about let-in or lapped dovetail braces I was hoping to get feedback on.
The frame I'm building is 16'x16', 3 bent, dutch-barn inspired design (low side walls, H-bents with thru-tenoned anchorbeams, steep roof pitch, etc.). My posts and plates are 6"x6", tie/anchor beams are 12"x6" and rafters & most braces are 4"x6". 
Would it be appropriate to use lapped dovetail braces to connect my anchorbeams and posts? I plan on using 6x6 stock with a ~40" length for these braces. I plan to let these in 1.5" and am concerned they may be too flimsy to support the loads on the frame (racking from wind load on the large roof and the planned loft atop the anchorbeams). What layout pattern/ ratio would you all suggest? Depth? 
I've cut and assembled my two low sidewalls- one with classic, hidden M&T braces and the other with let in braces, and I like the results of the lapped ones better (more snug). I can upload pictures too if that would be helpful/interesting, let me know!
Thanks a bunch in advance!

[Don P]

I for one would like to see pics/ sketches.What you are proposing is fine as far as the lap. That's a relatively short brace but it is a small building. What is the siding/sheathing going to be? Can you use that to brace the frame.

[slackwaterfarms]

Thanks for the reply!
Haven't figured out what the sheathing will be yet- probably some kind of plywood. 
Here's a pic of the braces for the sidewall, and a draft of the overall design (the braces haven't been drawn in as lapped ones, but i am considering lapping all the ones shown).  
 

 

[Don P]

There's where I was going with that question. "Load goes to stiffness". A 4x8 sheet of plywood is going to act as the brace structurally. Its ~107" long diagonal across a sheet so a far stiffer brace... as long as it cannot buckle out of plane.

If a tension tie ran from each main post out to the shed plate, forming another triangle, it would be another brace.

One neat thing about that frame. If the rafters are one piece, from ridge to shed plate, they are pretty much balanced, see-sawing over the aisle plate. There is no appreciable rafter thrust so a high tie up in the peak is fine, there is very little spreading force. Do the slightest birdsmouth possible over that aisle plate. Splitting the rafter is a concern there, don't give it a big notch to start a split from.

[slackwaterfarms]

Thank you, Don. As it stands the birds mouth over the aisle plate will remove a triangle of height ~2" (and legs 3") out of the 6x6 principle rafters and the 4x6 secondary rafters. Do you consider this too much removal? And if so, how do you suggest I modify my joint (bar shortening my principle post)? 

[Don P]

 Technically, the NDS and building codes say no more than 1/4 depth. It's better to be less or zero (bevel the plate and size it according to the damage). code also says if its a bearing it needs to be a minimum of a 1-1/2" seat.

An engineer friend dropped by a job where I had a similar situation, and I had overnotched the rafters. What we came up with was a bevelled 2x cant strip stuffed up under the rafters tight and ledgerlocked to the plate. If the rafter tried to, or did split, the ledger keeps it from being able to drop. Not ideal, that was a fix.