I see most treehouse's have knee braces to support the frame of their treehouse. I'm trying to find an alternative, if any, and also ask if my 2x4x12 frame will be strong enough.
Here are pictures of where I am in my current treehouse build.
I have 2 2x10x12's for my main lower support held into tree with 3/4" x 10" Lag bolts. I have 2 more 2x10x12's on top of those for my base support. they are also fastened to tree with 3/4" x 10" Lag bolts. Them frame and joist are made up of 2x4x12's and held secured with joist hangers and rafter ties.
I offset the platform to get more room on the left side. The only weight that will be on this platform will be the 1x4 flooring and railing. There will not be any structure built on it or heavy furniture.
My original plan was to set 2 4x4's in concrete and support the longest stretch of 2x10's. Here is a mockup i did to illustrate.
However, after walking on the corners I am realizing that is not going to be enough support. My first idea was to place 2 more 4x4's in those corners to left and right of the ladder. But I wanted this platform to be as independent from the ground as possible. But i am quickly realizing that might not be possible.
So here are my questions: 1) Would the 2 4x4's for the ladder and 2 4x4's in corner to left/right of ladder be sufficient?
2) Is there another way to do support those corners without using the ground?
3) Are the 2x4x12's I used in the frame good enough to support the platform? should I have used 2x6's?
Here is a mockup of what the deck will look like once completed