Must-Know Timber Framing Joinery (cutting square rule tenon from start to finish)
Vložit
- čas přidán 11. 07. 2023
- 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)
🪚 Japanese pull saw: amzn.to/3XQWKty
🪚 7 1/4" Skilsaw: amzn.to/3pI2sBf
🪚 Speed square: amzn.to/3Oa3b7s
🪚 Combination square: amzn.to/3XPI6T1
🪚 Carpenter's square: amzn.to/44EKQ7X
🪚 1.5" chisel: amzn.to/3NRW02J
🪚 3" slick chisel
🪚 Handmade wood mallet
Great job!
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.
I’m reading a Japanese joinery book right now. It’s impressive work. If you’re in Kentucky, have you ever gone to one of Chickadee’s workshops?
I might call that a good little Japanese saw ❤
Both saws
Really enjoyed this!
Awesome! Square rule is great. Everything fit together perfectly on raising day.
thanks dude!
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.
We split our time between north of you and south of you. We’re probably about four hours from you in the summer and 6-7 in the winter. I’m starting a project for friends next week - a small cabin they’re going to use for a home office. The property owner wants to have people over on raising day. Don’t know when that will be yet - I’m starting milling next week. We’ll get you an email address as the date gets closer if you want to know more about coming.
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?.
90 degree interior angles are prone to cracking at the vertex. The bevel spreads the stresses out so it’s less likely to crack.
Not sure I understand your question about the mortise. It looks like a rectangular pocket for the tenon.
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 :)
That's a reduction. It's done in square rule timber framing on the opposite face from the reference face. The bevel helps the timber not crack along that line created by the reduction. This technique is sometimes used for joists. Joists can also use a particular kind of "swoop" that's carved out to create the same function.
I'll add an explanation to the video description for anyone else who as the same question.
The house I currently live in didn't make correct cut outs on the joists and almost every one of them has split. The floor shakes and the house rattles whenever you walk. No good! Luckily the sills are strong and the rest of the house is well-built so it's still standing, but I do plan to fix the problem eventually.
Killionleon the square rule theory if to make allowance for Timbers that are not uniform dimensions. If you reduce the joinery to be exactly 7.5 inches on your 8x8 beam, you end up with a solid joint. Some timber is 7 7/8 x 8 1/16 at one end and another could be 8 x 7 3/4. Make each joint 7 1/2 and the problem is eliminated. Just more work.
Why don’t you use the full 2” for the paring work you do?
I have seen some high stress on the 1.5 that would make any one feel uncomfortable
Why didn't I use the slick on this one? I didn't have my sharpening stone yet. I re-ground the edge on the slick because it came too steep so it didn't work well on pine. The other video with mortiser you commented on is frm a different project and after I re-ground the slick.
That was really painful to watch.
I watched till the end. I’m a new framer and saw some good tips. Obviously if you are an experienced framer you might find there are efficiency points to give but he got the job done. Now do 11 more….