Daiku, thanks for the correction. That makes good sense.
Jim, Great drawing! Thanks. I will defintely file that one away.

In Jims picture, the 5/8 rule, works great. In one of Sobans books he shows placing the joist in up side down and adzing the bottom to the surface of the timber than flipping the joist right side up, no lay out once agin and there is that beautiful sweep. Tim

Jim, those are really helpful. Are there such general guidelines for soffit tenoned joists or other joinery style such as dovetail, or tusk tenons? tb

Isn't a soffit tenon and a tusk tenon the same thing?

Jim, I think they are nearly the same. Soffit tenons are located on the bottom side of the joist/beam while tusk tenons are located up from the bottom, more to the center some times with a housed soffit shoulder below it. My question of terminology with this is if you had a 4"x8" joist with a tenon at 4 and 6 inches down with the remaining 2" adzed off, is this a soffit or tusk tenon? Maybe this is a knit-picky question, but when yoour communicating on the shop floor it might make a difference. Tim

I always think of soffit tenons having the angled cut from the top of its tenon getting slightly larger at the tenons base, much like the diminished haunch cut seen on tiebeams. Also like Timbeal said of the tusk tenon , which has its tenon more centered and perhaps still shouldered on its bottom. I see the soffit also being superior in the shear value as its tenon is angled on top and full bearing dimension on the bottom, which also allows the beam it joins to, to not lose any wood on its edges like the drop in joists. tb

I have had a question as to how many framers are lapping floor joists the 1" and using a timberlock type screw? Daiku and Moe have referenced this in posts. I have heard that some engineers prefer this to a deeper lap or dovetail. Any truth to this? Whats the most common connection here?
I chose to go with a 3x4 lap on a 8x10 beam with a 4x6 joist and a 3/4 inch locust peg driven from the top. This would have left 2 inches where joist pockets were adjacent each other. I did alternate spacing so this wouldnt happen, but from a engineering standpoint I think you still only have two inches of relish there. I just felt better about it when spacing them.
I have also wondered if the 3/4 northcott peg is comparable in shear strength to the timberlock screw?
As for how the spacing looks I will let you know the frame isnt totally up yet. I think it will look great! Thanks for any insight. BB

I typically use 1.25 inch joist pockets. Here's the rationale: A dovetail, or some other joinery will weaken the carrying member, which will then have to be up-sized to compensate. The joint will be hidden by the flooring. You can't tell by looking at it whether it was dovetailed or not. Also, the screws will actually hold it down tighter, reducing squeaks. A peg won't do that. I'm just balancing what's traditional with what's practical. If old barn builders had access to these screws, you can bet they would have used them. CB.

Thanks for the response. Never thought about the squeak, much easier to cut also. It makes perfect sense to me! BB

Pictures people, please! They are worth a thousand words and I have a hard time understanding some of these descriptions, given some slightly different terminology etc..