How to build a tree fort

Are you thinking of building a tree fort for your kids? Do you want it to be waterproof and bugproof, but not spend too much money? I made this tree fort using mostly materials I already had. The most money I spent was on the paint, but that is totally not necessary. I didn’t take too many pictures of the progress shots, because I never intended to write about this. This tree fort was one of my “special projects”, as Tony likes to call it. I was able to get out of the house, build something with my hands, and keep my mind off everything that’s going on in the world right now. But anyways, this is how to build a tree fort. I hope you can learn some tips from mine and apply them to make your own tree house!

Find a location

For a tree fort, you need at least one tree. Two or tree are good too, but I happened to find four medium trees that were kind of close together. These trees are just down a path from our house, so close enough to the house, and yet not too far away.

Build the frame

We had just finishing building our deck, so I planned to build the frame of the tree fort in a similar way. We were given some old pressure treated lumber from an old deck that was torn down. That was zero dollars spent on the lumber. If you’re thrifty, you can probably find some free lumber by looking on a buy sell and trade site.

I nailed some 2″ x 10″s to the four trees. And then added joists every 16″ or so. With a tree fort, it’s not going to be square, but I did the best I could.

Make the walls

Using what I had, I decided to use pressure treated 2″ x 4″s for the walls. I just cut them down using a skill saw, and nailed them to the trees. I went up about 30″ on all four sides.

Frame the roof

I framed the roof in a similar way as the floor. Except I nailed the boards on the outside of the trees so there would be an overhang on each side. I did a slope on the roof so water would run off the back of the tree fort. 

Pressure wash it

I love pressure washing. This was old used lumber that was dirty and stinky, but after I washed it it looked so much cleaner and brighter.

Build the stairs or ladder

At first I thought a rope ladder would be a good idea, but that didn’t work very well. So then I just built a regular ladder, as you’ve seen in the pictures up till now. It wouldn’t be one of my special projects if I didn’t redo a few things a few times. Finally I landed on a less steep, sturdy set of stairs, and I’m much happier with these.

Finish the roof

We have some old barn roof trusses on our property, and they had some tin on them. I took off that tin and scrapped it together to make a fairly waterproof roof. In hindsight I built this tree fort a little too high, and I’m pretty fortunate I never fell off the ladder. 

Screen it in

I had an old dining tent that we never used, and I cut it up and used my air stapler to attach it to the three open sides of the tree fort. Also you can see here the first attempt at the door, which I also ended up redoing.

Bugproof with sprayfoam

I bought two cans of spray foam and filled all the cracks in the floor, ceiling and walls to make sure not many bugs would get inside. Once it was dry, I cut off the excess foam with a knife.

Paint it

This last part it totally unnecessary, but I love how paint can really change something. Plus, I’m a little vain and wanted the tree fort to match our play structure.  I used a solid stain so it only took one coat.

Then I just hung some cheap plastic shower curtains on the ceiling to hide the ugly tin, added some Christmas lights for a little ambiance, and started adding a bit of furniture. It still has a little ways to go to make it super comfy, but I would say this tree fort is not too bad with using mostly what I could find around our property. And that is how to build a tree fort! What projects have you been working on this summer?