Wish I was a clean as you go kinda guy, but alas I'm not, so I've got to get this under control before I can cut some wood.
Wish I was a clean as you go kinda guy, but alas I'm not, so I've got to get this under control before I can cut some wood.
Some goobered on paint to slow down the rust.
11pm and just made my first cut.
This is going to be the main support structure. A pair of pressure treated 2x12's (12 feet long) spaced out 28-1/2" (the diameter of the tree at installation height (as measured tonight).
Indy kid #1 has a swim meet in the AM, so progress will pick up again after that.
Home from the swim meet, so let's get back to the task at hand.
Cool build! How are you factoring in the growth of the tree (width wise) in the support structure?
In reply to EastCoastMojo :
I'm going to give it a few inches of room to grow per side. After which It will constrain the tree. I estimate it will take about 15 years to get to that point, at which time my youngest will be 17 and not care about the treehouse. I'll evaluate things at that time. But probably remove the whole thing. ( Or cut them off and put in new lags.)
I always forget stuff. Had to run to the hardware store for another $96 worth of fasteners.
There are some things I’m really liking about this so far... nice plan, I like the bed rails, and the pipe pivots...
Im curious about the lag bolts. Am I understanding that you basically have 2 supporting the structure (one on each side)? That’s not enough, and believe it or not those lags may not be big enough. You will be hanging on them in shear, which is not their optimum application.
That structure is gonna weigh about 1500 lbs, not counting wind load and movement.
Am I misunderstanding the application?
In reply to SVreX :
Shear strength on a pair of 3/4 inch lag bolts is really high.
You don't see the knee brace yet.
Knee brace attaches to that board with the square on it. (It's upside down right now)
Doc Brown said:The steel use for bed frames is a special alloy that is really really tough to drill through. Figure on burning up a lot of bits.
Moat of it in the US is rolled out of old railroad tracks in New Jersey. It is a high carbon steel and works like it.
Changed my mind about the lags, went with 12 inch long ones for main support.
I've got sweat and blood in the project now, only need tears....
Used a level to get the hole straight....
As you can see, also used a hole saw to remove the bark so the washers seat against solid wood.
Putting in the first anchor...
Indy-Barely Functional-Guy said:In reply to SVreX :
Shear strength on a pair of 3/4 inch lag bolts is really high.
You don't see the knee brace yet.
Sure I did- it’s in your plan! (Good job!)
It appears to be secured to the tree in a similar fashion as your other lags, but 5’ away.
So, what happens when the trunk grows between the upper and lower lags?
In reply to SVreX :
I'll remind you that the vertical distance (between the two attachments) doesn't change as the tree grows. It will only increase in diameter.....
I'll show you my attachment for the knee brace when I make it. It'll allow more growth than these upper ones.
Speaking of which:
Again, I like the concept. But your design does not account for the tree growing in diameter.
Poke around on this site a bit. I think you will find a lot of differences between a standard treehouse attachment bolt (TAB) and your design. There are some pretty good Technical specs, etc
Some of the primary differences:
- TABs are heat treated, yours are not
- TABs are 1 1/4” in diameter, yours are 3/4”
- TABs allow for about 6” in diameter tree growth (3” each side), yours allow for 0”
- TABs have a 3” diameter seat on the tree (collar). Yours are about 1 1/2”.
-TABs do not have a tapered thread they have a special 4 tpi non tapered thread
-TABs have slides to allow movement between attachment points (which are probably not necessary in your case)
The smallest lag bolts typically used for light loads in treehouses are 1” in diameter galvanized, but they still do not have tapered threads.
Like I said, I like your approach. It is FAR better than most home grown approaches. I just thought you might want to consider a few of the additional aspects.
Mrs Indy drove the tractor while I carried the back.
Lift up the first end....
A little more....
Lift far end....
He likes the progress 
In reply to SVreX :
I'll address (respond to) some of your concerns after I'm done for the day. I've got 3 hours of daylight left to work.
Plan B. Add peg legs.
This should ease Paul's mind a bit....
And it looks like another bomb went off in an outside of the garage.......
Edit: ignore those brackets on the peg legs. They are temporary, and yes they will get triangulated.
In reply to Indy-Barely Functional-Guy :
If you are using oak you darn well better use stainless steel. Oak has a lot of tannins. It will attack the steel and cause the steel to corrode which will in turn will cause the oak to rot
It will happen quickly too since the rain outside will speed up the reaction.
Huh. A treehouse with footings. 
Always wanted to build a treehouse as an adult. Even have a couple books on it but alas I have no tree. Living vicariously through your build. Keep up the good work! PS I am chomping at the bit for an update!
In reply to SVreX:
You sound like a T.A.B. salesman.
First off, my design Does allow for some tree growth, not the zero you stated. See all those washers? Yep, the tree can grow around those before it gets constricted. Not exactly 3 inches, more like 2" per side. An Oak in this climate is a slow growing tree. Washers are 2" diameter. I've got the 9 inches of threads buried in the tree, and the lags are loaded in shear, due to the welded in collar/washer combination. Even raw (non heat treated steel) has a very high shear strength in this diameter (3/4 shaft or 9/16 minor thread diameter) Think in the thousands of pounds. And yes, I have college level material science classes (and the internet) to verify it. I'm not concerned about it. I did however see the need for the the peg legs to help stabilize the torsional load on the entire house once I got the main supports up there. It was quite easy to rotate around the trunk with the long lever arm.
In reply to Lobsterpennies :
Thanks for following along. No progress today to report. It's Sunday and I'm resting with the family.
In reply to frenchyd:
Accounted for.
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