The treehouse project

This is one of those things that I want to have on this blog. It’s a unique project that is both something for my kids to look forward to and something I enjoy doing. It was started in early to mid 2020 while we were stuck at home. I had been hoping to build a treehouse for years and years and we had a tree that really needed to come down, so it is working out. Here’s my notes (originally kept in Apple’s iOS Notes app. By the date of the note creation this project started February 18, 2020 @ 8:42 pm. This post is all of my notes, from newest at the top to oldest at the bottom. From here on I’ll make a new post for each updates. This is the backstory, I guess.

9/12/20 – update

Floor of treehouse and deck is done. Ready to build walls and guard rails. Hopefully will pick up hog panel this weekend.

Finished floor dimensions, which determine the walls:

Other previous thoughts:

Secret compartment under floor above main supports on one side?

Trap door entry? Ladder on deck (rather than inside the house part) would be better for slide. But maybe not safer? Either way a kid could fall through trapdoor or off the opening in the deck for the ladder.

Platform deck plan

  • South 27” or so inches 5/4 x 6″ decking
  • North 70” 3/4 plywood cut around trees for house floor

Siding thoughts

South – 3/8” plywood, wall will be 6’ tall. Two vertical 4×8 sheets cut to length? Door will be 32″ wide.

West – milling cuts from locust? (Would need to mill all to have enough?)

East – 4” cedar fence pickets? Need 18 4” boards to cover front to back. 5 5.5” -6’ 5.5” tall.

North – 3/8 plywood, 5’ tall. Would use a 4 x8 horizontal and the two off cuts from the south to fill in.

Other fun stuff:

Monkey bars 21 1/2” long. 20 1/2+” between holes. 6 bars.

Platform finish:

Cut joists to length.

Stick remaining rim joist members up with 2-3 lags each end.

Lay out joists between trees.

Nail front side rafter ties in place.

Mark and nail rafter tie tabs to back side.

Install joist hangers.

House siding (original thoughts)

1 x 4 fence pickets?

8’ wall = 96”/3.5=28 pieces * $1.33=$38. Not bad really. Fastened with nails? House wrap first? Plywood? Overthinking this …

Platform deck safety railing and other ideas

Lots of inspiration from this project: Treehouse Update – M O D F R U G A L

Platform initial thoughts:

Thinking of cutting some of the support into the tree to cradle the 2×10 supports. At least to get through the bark so the lags have more wood to bite. Not sure if we need oval cutouts to allow tree movement, but this would allow wiggle room too when fastening boards to the tree.

If we cut notched/cradles we can get away with smaller bolts as the cradles will support a lot of weight. Based on the info below on lags we could use 5/8” stuff locally and be good With multiple lags.

>> ended up using six 5/8” lags and the threaded rod. Plus three 1/4” spax construction lags.

9/12/20 update: After these notes I have also added two 45-degree supports from the south edge of the platform to the base of the tree. So this supports a fair amount of weight, but most weight is/will be centered over the two main 2 x 10 tree supports.

Big question is how to make the platform. Two support boards and a platform on top? Or integrate the support boards into the platform? I like the look of the integrated platform/support but I think the platform on top of supports is easier.

> now that the two main supports are up, I think to take advantage of the support they provide, the platform on top makes the most sense. And is easier. Especially since they are at such a great angle to each other. (I had originally cut the ends of the 2×10 to 5.5″ to meet up with a 2×6″ but decided against that. It might look funky but I don’t mind it.)

Finally some lag bolt info:

“The half inch lag bolts are more than sufficient and can usually hold more than 200 pounds per inch of thread, if you use 3 lags that have 6 inches of thread biting into the tree and a factor of safety of 2, your weight limit is 1800 pounds. Also, same as above with two lags would be 1200 pounds.”

Tree house attachment lag size? – DIY

Not that I should be basing my decisions on internet posts, but I think the info is sound. I’ll be using 6 x 8” long 5/8” lags. Probably at least 3-4 inches of thread biting into the tree. And one 5/8” threaded rod all the way through the one tree.

Also will ideally cut a notch/shelf into the tree to support the 2x10s. Did not really do this. Just the lags, conservatively using the info above would hold 6 lags x (3″ x 200 lbs = 600 lbs each) = 3600 lbs. The threaded rod isn’t supposed to be as strong as lags for sheer, so maybe call that 400 lbs? It goes all the way through so there is no “pull out force” associated with that, all it is is sheer. I think we are good for almost any size platform house or whatever. (Calculated weight.)

Interesting treehouse similar to what our tree is like.

Hmmmm …

I was out looking at tree house stuff and realized the project is very close to the power lines … I’m not sure why this didn’t dawn on me before:

No temporary or permanent structures, buildings, in-ground or above ground pools, playground equipment or other fixed im provements should be erected in the right of way.

What I don’t know is if this applies to our power line … as I do not think the area is a “right of way.”

I am quite certain it does not apply. Looking at aerial photos there are many neighbors who have build structures, such as sheds and other things directly under the lines.

⁃ what I want to be careful of, then, regardless, is to not get too close to the lines.

⁃ Will reduce the height from 8 to 6 to help with that.

⁃ Probably will want the bottom of the platform just over 6 feet? So I can walk under it without ducking.

⁃ 6’ + (5.5 + 1.25”=6.75”) platform + (6’ inside + 1’ roof rise?=7’) = 13.5’ height.

⁃ Estimating power line height, trunk is maybe 9’ high. Power lines are at least double that. Let’s say 20 ft

⁃ 20-13.5=6.5 if the lines were directly above.

⁃ North Base of tree is about 10.5 feet from power pole. Pole leans slightly towards tree. Probably at least a foot closer. Call it 9 ft.

⁃ Alter plans so house is mainly south of tree? Tree is main support but on one end. Would rather not have and ground posts other than monkey bars. Angle 2×6 to support south edge (6’) of platform. Tree house would be over trunks.