Treehouse

We bought a house last month after living in a rental, and one of the first things my kids asked for was a treehouse. Here's the finished project after about a month of weekends.

When they asked for a treehouse, I said I'd need to see some plans first. This was on my workbench the next morning.

There's no shortage of trees to choose from on our property, so we looked for a strong multi-trunk tree...

...and we settled on this one. V-shaped, about 200 feet from the house, and with good views in all directions.

Here's a closer look. Both trunks are strong with no indication of disease or rot.

First things first, head to the store to pick up some wood and a helper.

The main supports for the treehouse are 2x12s anchored by 10" long 3/4" lag screws.

You want the beam to be able to sway with the tree, so you need to cut a slot for the screw. Woodworking is hard enough knowing that wood moves, but in a strong wind, tree wood can *really* move.

I bored a half-inch hole into each trunk for the bolts. A few big holes is better than a lot of small holes if you're trying to keep the tree alive.

Here's the first beam in place. I didn't consider that, due to the slope of the hill, the 6-foot height of the beam on one end would be 9 feet off the ground on the other end, and my ladder had broken during the move. The galvanized pipe was an improvised cheater to help me get the bolts screwed into the tree.

I put up a beam on the other side of the V (the right V is a V itself, so the two beams form a triangle), and attached the first of the 2x6 crosspieces.

Here I have the first two crosspieces and the perpendicular ends attached. Everything after this point was easier than everything before this point.

Here's a good side shot from after I had all the subfloor framing done. The ladder on the ground means "Kids, don't try and climb up there yet."

With this kind of support system, the platform will be wobbly without additional support, so I added the first of two corner supports and bolted them to the trunk near the ground.

The next step was decking. Nothing too complicated here, just leave space around each trunk for it to grow. The board on the far right is probably too close to that trunk, so I'll have to trim part of it out in the next year.

I started adding the vertical posts for the railing with carriage bolts. You can also see that I trimmed off some troublesome branches that are now on the ground.

The kids brought some tools up to help out.

At this point, I have some of the horizontal railing boards up and I've added a second V-shaped support on the right side.

I added a built-in ladder (finally). It's just 2x6s nailed and screwed together, nothing fancy.

It's steeper than stairs but not a vertical ladder.

The kids asked me to leave this board long. I don't know if their original intention was to mount the disembodied head of Vader on it, but that's what they did.

All that's left to do at this point is add a roof.

To avoid too much weight and too much work, we went with a canopy roof. If I had planned ahead, I wouldn't have had to replace the railing posts on both sides with taller ones to support the roof, but I did not. I was able to reuse the shorter posts anyway, so the only thing I lost was a bunch of time and energy.

I used a big PVC pipe as the peak of the roof, and I think that was probably dumb. I wanted to avoid using something that would wear out the tarp if it rubbed against it, but a sanded 2x4 probably would have been fine, and stronger too. Oh well.

The canopy is tied down using horn cleats. This worked well, but I should have planned their spacing a little better to get the roof as taut as possible.

Before-and-after shot taken with an app that I wrote for doing before-and-after shots.

The end.