Newbie stuck on <simple> joinery

[Jim_Rogers]

Jim, with the square rule method, (as illustrated in the maroon book), the timbers are pared down from 8x8 to 7x7s at the joinery.  So, even though timbers are pared down to get to the perfect timber inside, the rule of thumb, therefore, always applies to the rough timber?

Yes the rough timber is an 8x8 so the tenon is 2by2 layout.

You need to understand that when he wrote the maroon book he needed to cover his butt to make sure that every where the frame was built it would be safe.
When I told one of my timber framing teachers that I was going to cut that shed frame for a learning experience. And to use it to teach others timber framing he suggested several changes to make it easier. One was to not reduce it to 7" but to reduce it to 7 1/2". That saves a lot of housing work. The only place you may need the 1" housing would be at the tie beam to post joint. Especially if you're going to be storing something heavy above the tie beam in the loft area, like lumber for example.
If you're going to use two inch full dimension rough sawn planks for the roof decking you can space the rafters at 4' oc. (if you snow load is not real high). Everyone needs to verify snow loads for their area before making some joinery decisions.

Jim Rogers



 

The above frame was sold and erected in Halifax, VA: