Building a Treehouse Deck

If you’ve been following my journey, you’ll know that I purchased a commercial space, called The Wood Shed, here in the Hill Country of Texas. In the back yard area there is this small grove of live oaks and at the time there was a worn out tree house spanning across some of them.

I tore it down almost immediately but then started on building this 700 square foot floating deck that uses only the surrounding trees to support it. This was a massive undertaking that is most certainly among my favorite of all time builds so let me start at the beginning and explain the process. 

The first thing I need to mention is this took months of planning. Jacob, who is the lead carpenter on this build does have a background in building tree houses but we still ran the plans through several engineers, had the trees inspected by an arborist, and Jacob even did a detail 3D model of the entire structure and trees. 

When building in the trees, it’s important to remember that they are living, growing, moving things so you have to allow for their movement or you can end up damaging the tree and having a failing structure. There are these special bolts called TABS, tree attachment bolts, that are massive and are specially designed to build in the trees. Each one of these is rated at 10,000 lbs which is nuts to me.

This threaded portion here will be inserted into the tree until half of the bose is buried in the trunk.

Then the deck will be resting on this portion of the bolt which will be sticking out. 

In order to get a level, all of these TABs need to be drilled on the same plane however, getting a level line on 8 different trees was kind of a problem but Jake showed me a new trick for it called a water level. It’s a simple tool made from a clear flexible hose with water in it then it works on the principal that water will always find it’s own level regardless if the ends of the tube are touching each other or 50 feet apart.

To use the tool, I would hold my end of the tube still, at the starting elevation then Jake could move his end of the tube to transfer that elevation to the next tree. 

After repeating on the other trees and getting the TAB locations marked, we started predrilling. The TABs need about 8 1/2” of depth, so we made a mark on the auger to have a visual on the progress. The important thing to pay attention to on this step is that we were going in straight. Not only square to the tree, but also keeping the bit level. To check for square, one of us would hold a square to give the driller a visual reference on the left and right position of the drill. 

Then I would stop every little bit to check a level and make sure my up and down position was also good. 

Once the depth was reached, now the bit is switched out to a different bit that will enlarge the outside of the hole and allow for the boss to nest into the tree.

This bit looks like a forstner bit but has a long center pin that fits in the pre drill hole I just drilled which helps keep the forester centered.

This step was incredibly challenging. We needed to go about 3 1/2” into the tree and just to give you a better idea on time, this one hole took 45 mins. These live oaks are no joke! 

After getting it drilled through, now was to insert the TAB into place. A few things here, we would sanitize the threads and anything else that woulld be coming in contact with the freshly drilled hole….maybe overkill, but it’s an easy thing to do.

When threading it in, it’s again important that it goes in level so after every few turns, we would throw a level on it.

It’s amazing just how quickly this gets too hard to turn by hand. So we added in some leverage by attaching a pipe wrench to the TAB. Then, when that wasn’t enough, adding a cheater bar to the pipe wrench.

This turned out to be everybody’s favorite part of the process as we all took turns rotating the TAB into place.

There were only 6 TABs but it took us an entire day to get them all set. Something we ended up trying to make the drilling step go faster was to wrap a ratchet strap around the tree and the drill. Then as Jake would hold the trigger and keep the drill straight, I would slowly tighten down on the ratchet, allowing it to assist in pushing the drill into the cut.

To give you an idea on how effective this was, the first three holes took us about 45 mins a piece to drill, but the strap cut that time down to 10 mins….and it saved our shoulders and chests from getting black and blue. 

On to Day 2! 

One beam, the smallest here up front, was the only one we were able to make ourselves, the other two had to be specially ordered and delivered.

It was actually really cool watching it all get delivered because the two beams showed up on their own truck and the driver was able to tilt up his bed and dump it directly on site. If you’re in Texas and have timber needs then I’ll leave you a link below or HERE.

We started by trying to set the back most beam, which is the second largest. It weighs 470 lbs and is around 24′ long.

The first obstacle was simply how to move such a heavy piece into place. It turns out we were able to wrap a few straps around it and use the power of all three of us to drag it over.

Next thing to figure out was to get it lifted 9’ in the air….we were going to try a few chain hoists, but since I have a fork lift, decided to try that first. That worked exceptionally well.

Not only was it easy lifting but the ability to side shift the forks and therefore the beam left and right was easy peasy. However, it’s worth noting that Jake has lifted heavy items like this before with just the use of chain hoists. 

Ok, that went smoothly, but now it was on to the biggest beam….this one weighs 470 and is 24 feet long.

We actually tried the same method of pulling it but had no luck. So I went and grabbed another useful tool….a side by side. We strapped onto one side of the beam and used it to drag it forward.

Once the tail passed the trees, I used the fork lift to pick it up and bring it back into place. This way we could use the side by side once again to drag it in to the groove of trees and thread it into place. 

Every step on this project was something new to figure out. We would start off with the main objective of something, in this case, we need to get this beam over and up there, then just work out how to do that little by little until eventually, our objective was met and we could look to repeating the process on the next challenge. 

After setting the two largest beams, setting the third was a piece of cake! To make the smallest one….which btw: small in this case is 34’ feet long and weighs 950lbs …..we cut each beam to the same length then lamented it together to make up a three layered beam.

Even though it’s heavy, Jake and I found it wasn’t too heavy for us to simply lift it up and carry it over into place. 

Once all three beams were in place, now we could attach the unique hardware. Each beam has two TABs. At one end there is a static arrangement…

…while the other end has a dynamic arrangement.

The static will stay stationary but the dynamic has a long slot that the TAB goes through, which will allow movement room as the tree grows or moves.

First two days and two major steps down, now it was on to day three which was another tough one….setting the joists. The element that really makes this a tough job is that we need to get every single one 10’ in the air. Also, because of our spans and load, every piece of material we’re working with is not only huge and also very heavy. 

We started the day off by looking at the plans and marking off where each joist needed to be located on the beams. I can not stress to you how incredibly valuable having a set of detailed plans was. Jake invested so much time perfecting things digitally in the 3D model where every angle and length was accurate so that when we moved to the next step, he could easily call out the exact location or length or angle or answer to any other question posed. If you’re tackling something as equally complex, I highly recommend the time investment. 

So one thing that made joist day so tough is the weight of everything and getting every board lifted up and moved into place, but another was every joist required two different angles to be cut in on either end. Because I didn’t just want a massive floating deck that was 9’ in the air with no posts going down to the ground…I also wanted the deck to have curves which meant the front of a joist could need a 16.4 degree cut but the back might need a 117 degree cut.

We worked out a system where Jacob would make all the cuts on the joists, on the ground, then him and I would helf the joist up and onto the beams where David was stationed. From there, we would not only place the joist on it’s tick mark on the beam but also make sure the over hang off the beam was correct. 

There was a ton of blocking needed throughout the deck, not only in between each joists where each beam was but also around the trees. So David and I would keep ourselves busy while Jake would be cutting the next joist, by adding in the blocking. The blocking in between the joists prevent the joists from being able to roll.

then the blocking around the trees of course gives us framing members to attach to while also giving the tree plenty of room to grow in the future. With these being live oaks, we left about 7” of room on all sides of the trees. 

Just a tip if you’re working up high like this, we constantly would screw in temporary scraps on the underside of the joists to create a shelf to hold up the next board we would be putting in. This way you don’t have to hold it flush on top. 

The deck is divided in kinda of two distinct sides with three joists laminated together being here.

Day three was us setting these three joists then everything to the left side.

Day four we all showed up kinda smoked but ready to repeat the process to set the joists to the right of the three joists. 

The second day of any process is always easier in the sense that the system is figured out, the tools needed are set up and a groove between team members is established. Which is always a great feeling for me.

One unique thing we had to figure out on this right side of the deck was coming off at an angle from the three joists to the front beams. This was complicated because One) the steep angles were a new challenge for Jacob to figure out how to cut with a circular saw. The problem is the blade can only be set so far over. He ended up making up a jig that he could rest the shoe of the saw on to raise it up higher on one side and give him the additional angle needed. Then he would make two cuts in order to get the depth needed. That’s a great trick. 

Then the second thing to figure out was attaching them securely. We ended up cutting and placing these small blocks that have an angle cut in on one side. This way, as the joist was placed in it’s needed location we would have plenty of meat to attach into.

Throughout the entire deck we were using a combination of screws and nails. Typically using nails to pin items into place and get them positioned and set but then coming back with screws to squeeze things together. In some areas, like these angled joists we would also come back with metal straps and bolts to reinforce the connection. Other hardware used was joists hangers on any joists not on a beam….for these we grabbed the standard hangers but gave them all a coat of black paint before installing them.

After the angled joists were installed we went back to tossing up then installing the regular joists that spanned from the front beam to the back.

It was really cool at this point to walk under the deck not only is it beautiful to look at but it’s a crazy cool feeling to watch the progress as the day goes on.

Also on the front, it was spectacular to see the curves coming to life. You could walk under the front edge, looking up, and follow the bends that definitely give it a gracefulness but added so much additional work. 

Day 5 started with another slightly unique system, sister joists together in order to span from the center, largest beam, to the front most beam. These will make up the forward most area of the deck that will be the tightest radius but create a very quaint and cozy viewing or seating option, once the deck is complete. 

It’s a fun thing to experience, building a deck in the trees….because the more boards you throw up and attach, the more walking area you’re giving yourself. To get to one point to the other we would most often just balance beam across and stay up on top, but scaffolding and as many tall ladders as possible under was also a time saver. Oh and if we were working in one area for a bit, then just throwing up a full sheet of plywood to use as a sitting area and work bench was very handy. 

At this point, we were all three very tired….it’s not only hard work but it’s also summer in Texas. Thank goodness we had the wonderful shade of the trees themselves as we were building. But looking out over the deck from either the bottom side or the top side, it was extremely easy to feel proud and also excited by what we were doing.

Now of course there is a lot more to go but I’ve had to break this project into a few parts because there is so much involved. In the next episode I’ll start right here and show you how we capped off and joined all the tails of the joists to eventually create the stunning curves you see in the final deck.

Stay tuned if you’re interested in seeing it and leave me a comment down below on what you think about it so far. 

Things I Used in This Project:

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