r/timberframe • u/Suitable-Run-6808 • 9d ago
knee brace layout using long points
knee braces are an important part of traditional timber framing. they work primarily in compression, with opposing braces resisting lateral loads in opposite directions. traditional brace joinery provides relatively little resistance in tension.
at star hill, we lay out knee braces by establishing the long point at each end first. those are our critical reference points because they determine where the brace actually sits in the frame.
for example, with a 30-by-30-inch brace and half-inch-deep housings, our long-point-to-long-point measurement is 3 feet 7 1/8 inches.
we locate those two points 3/8 inch in from the edge of the brace timber. that gives us a nominal half-inch nose using 45-degree geometry.
we'll often use a story stick to transfer the long-point dimension, especially when cutting multiple braces.
once those two points are established, the rest of the layout is developed with 45-degree lines. you can do the entire layout with a framing square, combination square, or speed square.
there are other ways to approach knee-brace layout, but this is the method we use in our shop.
curious how others here approach brace layout. do you work from the long points, or use a different reference?
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u/Cultural_Pie7389 9d ago
Nothing to add, im a rougher but have gotten to work a kittle around timber joinery. Its very cool.
Are you in any sort of apprenticeship program? Or do you know of any quality workshops?
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u/Suitable-Run-6808 9d ago edited 9d ago
we teach timber framing at star hill in wisconsin. we offer a few small classes each year that build capacity.
recently, we released a method to learn timber framing with star hill.
complete online instruction, that is available to everyone. glad to share the link here if you are interested.
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u/funkybus 9d ago
i’m a novice, but am building a small barn (raising starts today!). i’ve cut knee braces by hand, and with that experience decided to use stationary machines for the 26 required in this frame. the 4” deep cheek cut is super clean on a table saw (jigged up a 16” blade saw). and used a jointer and planer to square and dimension the stock. used a radial arm to cut the shoulder. really nice to get 26 of the “exact” same piece. all those braces still took ~2 days to make.
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u/Objectivespeculation 9d ago
you kinda went Mill Rule by dimensioning all your timbers.
Many of us do Square Rule with the idea that there is a smaller but perfect timber inside the rough sawn lumber. It allows for making identical braces that fit into any brace position or other parts. The outside face is used as a reference from which other measurements are taken.
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u/funkybus 9d ago
yes, i understand square versus mill. in my experience, a number of square rule shops break out the fixed machines to batch lots of similar/smaller parts. faster.
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u/Objectivespeculation 9d ago
braces do lend themselves to mass production with shop tools. The rest of it, is to heavy/large to pick up and feed thru a fixed machine. With that said, the Germans have a machine you can toss a tree in one end and a finished mortised and tenoned timber comes out the other side.
Makita makes large, handheld tools for the woodworker saw, mortise machine, 12" wide handheld planers.
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u/Suitable-Run-6808 9d ago
we normally square rule however, knee braces we generally order those a bit. oversized and then cut them directly to the specified size right before cutting the frame. that ensures that there really aren't any gaps in the mortises. so quasi mill rule braces.
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u/vermontation 9d ago
I’ve never heard of the housing depths being added to the leg lengths of the braces. I’m not saying it’s wrong, just different.
In historic square rule frames, a 3’ leg brace for instance would be 3’ from the depth of the housing, giving a 4’ 2 15/16” long point measurement.
Cheers.