Knee Brace Tenon Design

[tadamson]

I've seen various posts touching on this topic, but none that address my exact question...

I'm wondering what is the most appropriate tenon layout for a knee brace that is centered?  I have 4x8 braces going into 8x8 posts.  The wife wants the braces centered, so I was going to center the tenon as well.  That made me think - does the tenon need to be centered just because the brace itself is centered?  

Seems like a 2" shoulder and and 2" tenon would be the easiest to cut.




Here is a centered 2" tenon with 1" shoulders.




Is there any reason to choose one over the other?  Or some other variation?

[Ljohnsaw]

I am doing 4x6 braces with offset tenons because it is easier.

[flyingparks]

Tenon does not need to be centered. It's much easier to offset the tenon. In my experience, Exterior walls have braces that flush to the outside so wall materials (siding sheetrock...etc) will plane easier. If you have 4x8 braces going into 8x8 posts then technically you can have one brace that will work to flush with exterior and center with interior. You just need to figure out where to set your mortices...mortici...

[bannerd]

Non-centered one is easier to work with.  You can take a circular saw and cut a bunch of times and then knock the "fins" out with a hammer.  If you mess up on the angle keep in mind you can route a pocket around the mortise, in theory, though.. the offset peg should draw it closer over time.

[tadamson]

Thanks for the feedback.  It is appreciated!

[Jim_Rogers]

Centered tenons on the brace are harder to cut because both shoulders have to be in the same plane.
Shoulder on either side of the brace mortise also have to be in the same plane. Harder to cut.
The depth of the shoulder on either side of the mortise is difficult to measure accurately, because that side of the post is not a reference side. That is a variable side.
You can do it but it will be a challenge unless you're working with planed smooth and accurate timbers.
Watch this video to see how to measure your housing pocket depth:
Centered brace pocket/mortise layout and measuring - YouTube
Jim Rogers

[tadamson]

In theory, since my structure will have no outside walls, any face of the post could be the reference face - correct?  So my brace pockets could be on the reference and adjacent faces?

I'm still learning the square rule and try to keep reminding myself to keep it simple.

[logman]

Took me about 2 minutes longer to do a centered tenon compared to an off set.