Must-Know Timber Framing Joinery (cutting square rule tenon from start to finish)

Discover the process of cutting one of the essential timber frame joinery techniques: the tenon.

Although my 7x7 timber is pretty good, it isn't perfect, so I decided to use the square rule to lay out and cut this tenon. The tenon also features a reduction with a critical 45º bevel. This bevel prevents cracking that can ruin your structure.

The reduction, which happens around minute 19, is part of square rule timber framing. The reduction is made on the face opposite the reference face.

My current home is a 1908 farm house with improperly notched floor joists that have all split because they lacked this bevel. The floors shake whenever you walk (and I need to put a lot of effort into sistering in new beams to fix the problem).

Knowing how to use the square rule is essential to timber framing with "imperfect" logs. It works with logs that are rough sawn or not perfectly square.

Square rule timber framing is when you all your measurements from a reference face. It's ideal for use with hand hewn logs.

This video shows cutting a tenon from start to finish. Most of it is shown at 2x speed so you can see all the necessary steps in half the time it took me to complete. The entire tenon took me a little under an hour to cut.

Tools used include: (affiliate links, I may earn a commission on qualifying purchases)
🪚 3" slick chisel
🪚 Handmade wood mallet

[dp]

Do you ever watch videos of Japanese timber framers? Their tools and techniques are unsurpassed and have taught me a lot. I think you’d learn a lot from them as well.

[markthomaswilliams]

this is. so neat to watch, i am getting excited for my project

[dp]

I like these structures you build. If you don’t mind sharing, where are you located? I’m in eastern Kentucky and could be interesting in lending a hand on a project if you’re nearby.

[kilianleonkilianleon]

Great video! I learn a lot from those close up shots. Could you pls explain the "critical" bevel at 20:24 a bit more? I have never seen this before on a tenon. And why removing the part at 18:57 at all? Thanks :)

[paultuell]

What is or which side is the top and why does the bevel stop the timber from cracking? what does the mortise look like when it joins the tenon?.

[fredianoshahid]

might be a novice question, but why not use a sander for the finish touches rather than a block plane?

[ParaDox-xbqw]

An industrial band saw would do just nicely.

[georgewhitehouse]

Why don’t you use the full 2” for the paring work you do?

[michaelheurkens]

You might want to sharpen your chisel and plane irons. They seem to be dull, wasting your energy and causing too much clean-up time.