Multi Level Tree House From Recycled Materials

I wanted to share the treehouse I built for my kids for the trash to treasure contest. I have always loved using recycled materials to build things around my house. There is something especially satisfying knowing that you are preventing hundreds, if not thousands of pounds of pressure treated lumber from heading to the landfill to just sit there and not rot. With a little bit of patience and some scouring of good ole' Craigslist you can find some fantastic materials to build a small shed, greenhouse, workbench, or, in this case, a treehouse. I want to share with you my multi-level treehouse that cost me around $400 from start to finish. The upper structure is about 45 square feet in area and has a ceiling with a height between eight and six feet high. It has been through some wicked wind storms over the past year and has not had a single issue. It is much more safe than a traditional treehouse since it has multiple levels, breaking the 13' height of the upper platform into two different climbs (it's a lot better to fall 6' than to fall a full 13'... although it's much better to just now fall :)

I am still adding more pieces to the treehouse and most recently added a great pulley system using an old bike wheel. I will likely add more details to this instructable as I add more parts to the treehouse but I hope what I share here gives you some instruction and inspiration to build an awesome treehouse for someone young or young at heart.

Step 1: Find Your Tree

Building a treehouse requires a tree (yeah, I know that was pretty obvious). I have seen a good number of "treehouses" build with just four posts attached to the ground and not tree involved. These get to the point of putting a small living space up in the air but there is something to be said about being up in the trees. On a hot, mid-summer afternoon there is a breeze 13' feet up to moves the humidity around a bit more. Birds flit from tree to tree and it feels like you are completely enveloped in the lushness of the forest. On a still winter's night you hear not a sound and see a deep canopy of stars. There's just something about being up in a tree.

Picking the right tree isn't always so easy. Going through the Arnold Arboretum in Boston I saw literally dozens of trees that would have been amazing treehouse trees... this is what inspired me to search through my own forest for a tree that would work the best. Since our property was once a farming field a hundred plus years ago most of the trees are relatively young and not quite "branchy" enough to be a proper treehouse tree. I took my kids out on a mid-winter scouting mission to see what we could find. I knew that I wanted a tree that had either a good number of large branches to incorporate into the treehouse or a tree with multiple trunks to build the main platform in between. I knew that I wanted to build the treehouse at least 10' off the ground, not so high that it's scary but not so low that it will be "uncool" as my kids got older and a bit braver. I also knew that I wanted the treehouse itself to be close enough to the house so the kids wouldn't get freaked out but far enough away where they felt they were on an adventure. There was literally only one tree that fit the bill. It was a relatively large red maple that had lost one large branch during a severe ice storm that hit Central MA in 2008. It had five large and strong trunks radiating from the central base trunk and it opened up just enough to have a structure built somewhere between 10 and 13' high. I selected the tree and when Spring came bounding around I began the process of securing as much free material as I could find.

Step 2: Score Some Free Lumber

Finding free lumber and materials on Craigslist is something of an art. I have shown up a few times at a prospective lumber horde only to be extremely disappointed. Either there was immense amounts of rot, nails the size of railroad stakes in numbers that would rival the population of a big city, or even worse, a really awkward situation (think about taking a kid's swing set down because a family is moving, but the kids are watching you all the while). I have found that swing sets and play sets are actually some of the best sources of quality materials. Not only are they often made out of superior materials such as red cedar or pressure treated lumber, but they often include heavy posts and beams that would cost you a small fortune at a lumber store. Add to this that the hardware is often galvanized or even stainless steel and you really score big if you are willing to invest the time disassembling them. Another excellent source is old decks and porches. These are often decks that have not been properly flashed to a house and have caused rot along the rim joist of the house. A new homeowner is frustrated to no end by the ineptitude of the "no talent idiot" who did the job and just wants everything removed. This often includes PT 2x8s and other perfect materials to build a treehouse, all for free, with some manual labor of course. It pays to have a truck at this point so that you can layer the nail-ridden boards on top of one another so you can pull out the iron spikes on your own time (it's a bit awkward to do it while hanging out with the frustrated homeowner).

If you are taking apart a swing set it's best to leave as much of it intact as you can. I was able to use an entire platform from an old swing along with a number of railings that had already been manufactured. Removing nails can be relatively easy if they are not too ridiculous in size, otherwise it might be easier to put a cruddy saw blade in your circular saw and cut the ends off the boards, quickly and effectively removing all of the nails. You can also use an angle grinder with a cutoff disc in it to just zip the nails off at the surface of the wood. I used this method for the majority of the boards taken from an old gazebo since the nails were ridiculously long and thick.

Step 3: Build Your Platforms

One of the most important things about building your treehouse is that you need to make sure that the platform is extraordinarily stable, yet able to move with the tree. If you anchor your platform as tightly as possible to the tree you will quickly discover two things; first, the tree doesn't move all in the same direction while the wind is blowing, and second, the ground doesn't move while the tree moves. In the first case I am referring to the necessity to leave some room for the treehouse to move while up in the branches. I cantilevered one section of the main platform between two trunks of the tree, secured one section to two trunks that move in the same direction (most of the time) and then, most importantly left plenty of room for the tree trunks to continue growing up and out. The main upper platform also had an addition that was ledgered to the platform between the trees. I used one 2x8 as a ledger board then used two 10' 4x4 PT posts to run the joists to. These two posts, along with the ledger board, hold up the main structure. The posts ARE NOT set into the ground but are instead tied together and then braced by the joists above. If they were set into the ground the structure would have definitely been torn apart by now with the winds we have. You want the entire structure to move with the tree, not resist it. The majority of the joists had to be purchased but I was able to scab some of them from my lumber finds. All of the decking for the platforms was 100% recycled lumber. I made sure to give plenty of room around trees when the decking surrounded them.

The bottom platform was the entire platform from an old play set. I ended up putting this up by myself using a couple of ropes and some pike poles to push it up into place while I went about building supports underneath. The lower platform breaks the entire treehouse into two levels making it immensely safer and an absolute blast for the kids. I used one of the swing set monkey bars as a sloped ladder / stairs to get up to the first platform and then used a set of stairs from a different play structure for the stairs going from the lower platform to the upper platform.

Step 4: Frame the Structure

Before I started to build the structure I installed a pressure treated bottom plate around the entire perimeter of the structure. This will prevent rot in the kiln dried lumber used to frame the treehouse. I used some of the recycled stuff I scored from a deck teardown. A friend of mine was able to score a ton of free lumber from a prefabricated, manufactured home factory. He picked up a few truck loads of 2x4's, 2x6's, 2x8's, and even some 2x10's and he ended up giving me more than enough to frame the structure of the treehouse. All of the wood is kiln dried and not pressure treated, so it will need to have a good roof over it and some decent siding. I framed the structure to have two windows and one door. I won't go into extreme detail on how to frame a structure but the basic idea is to make a rigid four-walled mini-building that can easily resist torsion. Lot's of blocking between studs and double headers above windows and doorways will help with this. I used two ridge beams attached to the notched posts at all corners. The roof joists were attached between these two ridge beams and then purlins were put into place between the roof joists so there was even more rigidity and plenty of places to screw down the metal roof. I ended up getting a door off the side of the road to use as the main entrance to the treehouse, so I framed the opening around that.

Step 5: Add Some Safety to the Platforms

Treehouses freak most parents out... and for good reason. A poorly built one is extremely dangerous and could result in catastrophic injury. A well built one will stand in the trees for years... maybe even decades. No matter what, it is important to have plenty of safety with something that is 13' up in the air. I installed railings around EVERY opening. These were actually the safety railings from a play structure I took down. They were already in one piece and worked perfectly to block off any areas that a kid could accidentally fall through (other than the stairways of course). They are mostly attached to the platform's surface but I did tack the tops into a couple of trees with long screws that were not 100% screwed in, in holes drilled in the railings, to allow for movement. I also installed posts at some corners to attach the railings to. Once again, all of this comes from left over parts from the play set, one post even had a steering wheel in it already that worked perfect at the "stern" of the platform.

Step 6: Add Siding and a Roof

The one thing I had to purchase was the siding. I looked all around for something free but only found junk that would ultimately ruin the appearance of the treehouse. There is a local white pine saw mill near our house that is very fairly priced so I went that route. I was able to get all of the siding I needed for about $200, which, after everything else being nearly free wasn't a bad deal. The siding is shiplapped and I simply used pressure treated screws to attach it to the frame. I cut out the window openings and door openings after putting the siding up and then installed the roof. The roof was leftover roofing from my wood fired oven build. When they deliver the roofing it often has scrap pieces on top to protect the stuff you paid for... this ended up being a perfect size for the treehouse. I used my leftover corrugated metal screws to attach the roofing to the purlins and joists for a nice, tight, protected structure.

Step 7: Add Some Windows and a Door

The windows for the summer are just simply screens that have been stapled to frames inserted into the openings. For the winter I have a big piece of plexiglas that I got from an old rear projection television. I simply put it against the screen and put furring strips around it. The longer window is a sliding window made from another piece of the old television. It's kind of a weird material that lets light in but you can't see anything through it. I tell the kids it's a spy window since they can slide it open a bit and see outside but no one can see them... suffice to say they love that. The door is an interior passageway door with a heavy poly on it that someone was throwing out. I used some old spring hinges on it to keep it shut when the kids forget to close it (not that they would ever do that). It's really cozy in there during the warmer winter days and the kids love setting up camp there for the day with the windows in place.

Step 8: Making It a Home Away From Home

At first it was tough convincing my kids to use the treehouse. I was frustrated, to be honest, and was really wondering if they would ever use it. My wife, being much more sensible than me quite often, said that it was close to the house for us but as young as they are it seems so far away. We have bear, moose, coyote, and lot's of other wildlife in our woods so I understand that they were a bit nervous to be back there on their own. Now, they are back there all the time. They bring back lunch, set up clubs with friends, and get lost in their imagination for hours. I love it! But like any good project, it never ends...

Step 9: Using the Materials Left Over for Even More Fun and Adding Some More Excitement

With the left over play set materials I ended up building another mini platform in a pine tree, added a small slide that came with a swing set, and then built a 100' zip line right near the treehouse. This just adds to the fun and keeps them playing out there even more. We also added a really cool pulley system using an old bike wheel. I had my kids join in on the engineering of this one and they loved the challenge. We simply use the bikes spinning hub as the pulley (it's set between two parallel boards). You can put the rope over the rim of the wheel to see how many pulls it takes to get the milk crate to the top or put it on the hub itself and see how many it takes... yay for physics in the treehouse!

Step 10: Final Thoughts and Moving Forward

I still have plans to add on to the structure this summer. We have our own swing set that is now going on 25 years old, that we received from some friends. The plan is to use the playhouse of the swing set as another platform and to use an old cargo net we got as a bridge between the two. There are many more ideas and with my kids being still so young I am sure we will get years of use out of the the whole shebang!

I absolutely love building with recycled materials. I love the challenge, the fact that I am saving materials from a landfill, and I love saving a few bucks while I am at it. This treehouse has been through some crazy weather and it is as solid as the day I first finished it. I hope that this inspires you to save some landfill destined planks and try your hand at an awesome home away from home in the trees.