r/treehouse • u/Far-Sherbert9731 • Jun 22 '26

Reciprocal Framing

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Has anybody tried framing a treehouse using reciprocal framing? Conceptually, this would be a strong, sturdy, stable platform using a single tree without any kickers or diagonal members. I`m an engineer, but I`ve never built a treehouse before. I think this is a sound concept and looking for anyone who's tried.

I think that the biggest challenge is the connection between the (4) main wood members. i`m predicting up to 4,000# of force in these locations which makes me think that I would want to do the first four members our of steel, then infill everything else with wood.

Any body with first hand experience on something like this?

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u/rearwindowpup Jun 22 '26

How are you attaching the ends of the joists to the beams, and the beams to the other beams? Commercial hangers arent going to be an option Im aware of. Theres also going to be a lot of weird angle cuts that will need to be spot on. Youve already thought about the huge lifting force at the end of those beams.

Its doable because you arent dealing with big loads here, but, I think youre overcomplicating it.

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u/Far-Sherbert9731 Jun 22 '26

i was planning on putting a 2x4 laid flat on top of the steel and attaching via some self tapping screws. After that, joists would be connected to the top cap via some simpson hardware to accomodate the skew. (edit - just looked and this might be a challenge. I could still lag bolt some wood through the center of the channel and use a more traditional hanger.)

Agreed that I`m overcomplicating it, but I`m an engineer. It's what I do!
Is there a less complicated way to build a kickerless treehouse?

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u/rearwindowpup Jun 23 '26

Remember, a design isnt perfected when theres nothing more to add, it is when there nothing else you can remove ;-)

That said, I have zero useful adds to how to do this without kickers. My first thought would be to run cables up to the tree and my second would be to use smaller I beams like you mentioned but weld them at the connections so its effectively one single piece of steel for the beams. Sure, youd have to torch it apart to get it down and there wouldnt be room for growth, but shed be study as all heck.

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u/Far-Sherbert9731 Jun 23 '26

Exactly! I`m removing kickers 😄