How to Build a Tree House or Tree Fort

Video Transcript

Video Transcript

RON HAZELTON:
Well, for this project, I'm headed to California. Beverly Hills, to be exact. Now Andy Lick and Jim Freeberg are neighbors out there and good friends and they want to build a treehouse for their kids right on the property line, so I'm going to see if I can lend a hand.

This one right here.

Jim and Jason come over and together, we decide the exact location of the treehouse.

Hi, Jim. So how high do you guys think this should be? How high do we want to make this treehouse?
JIM:
Like about all the way over there.
RON HAZELTON:
All the way over there.
MAN:
What do you think Annie?
RON HAZELTON:
Branch right here?
KIDS;
Yeah, yeah.
RON HAZELTON:
Now Danny and Jason chose this tree because it straddles both of their back yards, so they've asked me to design a house that's accessible from both yards. Two entrances with two matching ladders. In designing the treehouse, I'm taking two things into consideration.

I want it to be safe and I want to avoid damaging the tree. So we're going to build a platform supported by four legs or posts. One of these posts will actually be the tree itself.

Okay, Andy, board number one. There you go Jim, over on your side.
JIM:
Fits great right in there.
RON HAZELTON:
We begin by positioning the first frame board in the crotch of the tree. Now, this will help us determine where to install the other three posts. Now we'll place the second frame board in position and support it with a temporary brace.

Now this is just a temporary post, just to hold things together.

We clamp the frame board and the temporary brace together. Then drop a weighted line or a plumb bob to the ground below.

That will allow us to transfer that mark which is where I want our post to land, right down here to the ground so we know where to dig our post holes.

Jim drives in a stake to mark the spot, I circle it with chalk and Andy uses a post hole digger to dig the hole. We pour three inches of gravel into the bottom of the hole to provide drainage, then drop in a pressure treated four by four post.

All right Jim, now what you need to do is kind of stand right, right here and sight this bubble here. Move it back and forth this way until the bubble's between the line.

A post level will let us know when the post is perfectly vertical, then Andy clamps the post to the frame board to keep it from moving.

Okay, all right, let's mix up some concrete. Now this is just dry mix concrete. All you have to do is pour this in the hole, leave it about three inches from the top, and then we'll add some water. We have to do very little mixing for this.

This rapid setting concrete will harden in about 20 minutes. But we'll wait at least a couple of hours before putting any weight on the post.
ANDY:
Ron says about a gallon.
RON HAZELTON:
Okay, guys, why don't you go to the other side, set the other two posts.

With our first two posts in place, Andy and Jim head to Jim's back yard to set the remaining two. Now remember, we're creating a four sided frame up there in the trees. We've done these two sides, now it's time to work on these two.

I hold the frame board in place while Andy and Jim attach it to the first two boards with rust resistant screws.

Okay, gentleman, good job. Already it's solid.
MAN:
Okay.
MAN:
It really is.
RON HAZELTON:
Okay, let's do the other side now and that means we've got to go to your yard.

By the time we finish Jason's side of the frame, we are just about out of light. So we decide to break for the night. First thing in the morning we get to work, permanently attaching the post to the frame. Andy drills a clearance hole through which Jim hammers a carriage bolt.

Andy adds a washer, then a nut which he tightens with a socket wrench. While the two neighbors go to work on the other posts, I use my Japanese handsaw to trim off the tops. Next, we take a break from the treehouse to construct the two matching ladders. We'll build the ladders by boring holes in a pair of two by fours and inserting dowels for [   ? ].

Planting the two by fours together will insure the holes are aligned.

Come on in, we'll start drilling these. We can start right here, it will be fine. This is a portable drill press --

This inexpensive accessory can be purchased at any home improvement center and keeps the drill perpendicular to the surface.

I want to just pinch the ends on a couple of these. Sometimes this will help to get them started.

Compressing the ends of the dowels will make them easier to insert. They'll expand later, making a snug fit.
MAN:
You make it look simple, Ron.
[MUSIC]
RON HAZELTON:
Finally we use a portable nail gun to pin the dowels in place.

Yeah, you can smell it too. All right, one ladder.
[BOTH SPEAK AT ONCE]
For one side, right?
MAN:
Yeah.
RON HAZELTON:
We need, we need two of these.

Once the second ladder is complete, it's time to install two joists that will help support the floor or decking.

Okay, Jim. This is the first of two joists that we're going to be putting in here that will stand this frame -- Jim, put that in right there. I've clamped a little ledger right here so that we don't have to struggle holding this end up.

With both joists screwed into the frame, we're ready to begin laying the deck.

Now this is the first plank on our decking, so it should be flush with the edges.

We attach each plank to the frame and joist with deck screws.

That's it. All right guys, we're going to put half inch spacers between these. So lay this right on top of the joists.

Spacers create just enough distance between the boards to allow water and small debris to fall through. While Andy and Jim put in the rest of the decking, I start working on the wall frames. Each frame is made of two end posts with two by fours top and bottom and two studs in the middle.

Now to get everything screwed together just right, we need a little extra help.
MAN:
We got the last one in.
RON HAZELTON:
Okay.
JIM:
Okay, all right.
RON HAZELTON:
All done?

Now we're ready to frame our walls. One side at a time, we attach each wall section to the deck and to the adjacent section till we have all four walls in place. Now it's time to enclose them.

All right guys, this is the, I'll call this the exterior sheathing for the house here. So you decided on six inches, right?
JIM:
Yeah.
RON HAZELTON:
Yeah, I drew you a line right there, Jim so --all the way to the corner.

JIM:
All the way to the corner?
RON HAZELTON:
We tack the boards in place temporarily, working our way around the outside. Once all the boards are positioned, Andy secures them permanently with screws and before long, this Beverly Hills treehouse is ready to be lived in.

All right guys.
[SEVERAL SPEAK AT ONCE]
What do you think, how do you like the treehouse?
KIDS;
[SCREAMING IN APPROVAL]
RON HAZELTON:
Are you guys moving in up here permanently? You're roommates now huh?

Roommates with their own private entrances in a treehouse all their own.

Goodbye.

Build a tree house of pressure-treated two-by-eights, four-by-four posts and other pressure-treated wood that will last and be kid-safe.

Construct this kid's tree house or fort and children will play there for hours. A perfect do‑it‑yourself project with neighbors, the tree house design uses the tree as one support post and straddles a wall to offer access to both families. Build by this plan and the tree house will be safe, won't damage the tree, and will last for years.

Position the First Frame Board for the Tree House Platform
Step 1

Position the First Frame Board for the Tree House Platform

Place the first two-by-eight pressure-treated frame board in the crotch of the tree to position the tree house platform and use the tree as the first support post

Position the Second Frame Board and Chalk-mark the Post Hole
Step 2

Position the Second Frame Board and Chalk-mark the Post Hole

Position the second frame board and brace it. Drop a plum bob from the board to the ground, marking the site for the first post hole. Chalk mark the perimeter and excavate with a post-hole digger to two feet.

Add a Gravel Base and Level the First Four-by-four Post
Step 3

Add a Gravel Base and Level the First Four-by-four Post

Pour in a 3-inch gravel base and drop in a four-by-four post. Use a post level to insure that the post is vertical. Clamp the post to the frame board to keep it from moving.

Set the Three Posts in Quick-Dry Concrete
Step 4

Set the Three Posts in Quick-Dry Concrete

Add dry-mix concrete within three inches from the top of the post hole. Add water and tap the wet mortar to help the water penetrate the dry mix and eliminate air pockets. Set the other two posts the same way.

Complete the Tree House Frame and Square the Corners
Step 5

Complete the Tree House Frame and Square the Corners

Add the remaining two frame boards to complete the 4-sided platform with "square" corners. Drive rust-proof screws through the corners to secure them.

Attach the Posts Permanently to the Tree House Frame
Step 6

Attach the Posts Permanently to the Tree House Frame

Pre-drill through each post and the frame and hammer in carriage bolts. Add a washer and nut and tighten the nut with a socket wrench. Trim the post tops flush with the top of the frame using a Japanese handsaw.

Construct Two Matching Tree House Ladders
Step 7

Construct Two Matching Tree House Ladders

Clamp together two pairs of two-by-fours as ladder rails and identically pre-drill each for rungs with a portable drill press. Pinch the ends of heavy dowels and insert through matching holes in each set of rails. Nail them in place.

Attach Joists and Secure the Deck Planks
Step 8

Attach Joists and Secure the Deck Planks

Use rust-proof screws to secure two two-by-eight joists across the platform's base flush with its top. Lay deck planks perpendicular to the joists, allowing half-inch gaps where water and debris may fall through. Screw them to the joists and platform.

Frame the Tree House Walls
Step 9

Frame the Tree House Walls

Construct four wall frames with four-by-four end posts and two-by-four studs and top/bottom rails. One at a time, position each wall frame at each side of the platform and screw it to the deck.

Sheath the Wall Frames and Enclose the Tree House
Step 10

Sheath the Wall Frames and Enclose the Tree House

Cut 6-inch pickets from exterior sheathing to enclose the wall frames. Work around the perimeter to position and tack them with a nail gun. Reinforce them permanently with screws.