Introduction: 2-Story Cardboard Clubhouse

About: Ordinary guy with no special skills, just trying to change the world one backyard invention at a time. See more at: On Twitter - @300MPGBen and at

With a young and active child at home, it's challenging to keep her busy and entertained.

While we have a nice park not too far away, it's still a trip in the car just to get there. The backyard is somewhat bare, although it's starting now to fill up with DIY playground equipment, such as the 5-Gallon Bucket Swing and Soda Bottle Sprinkler.

While I was busy working on another project, I realized how much cardboard "waste" I was going to have. Rather than drop it off at the recycling center, why not make it into a fort or clubhouse or something else fun for the Little Girl? Anything that could keep her entertained for a while would also make The Wife much happier as well.

So, instead of just "throwing away" a bunch of cardboard, I turned it into an opportunity for some family fun and DIY backyard good times!

By the time I was done, this really became three projects in one - the two-story clubhouse, the cardboard tube ladder, and even a cardboard slide!

So come along. Let's build the Cardboard Clubhouse!

Step 1: Tools and Materials

To build the clubhouse, you'll need lots of cardboard and a few tools!

  • Two or more large cardboard boxes, such as appliances come in, extra thick cardboard is good.
  • Roof material - more cardboard or salvaged/recycled specialty material
  • Zip Ties - I like the 8" black ones, and I always buy an extra bag whenever I see them on sale.
  • Short Drywall or Wood Screws
  • Long Drywall or Wood Screws
  • 2x4 lumber to frame the slide
  • Wood glue, School glue, or Hot glue and gun

  • A good sharp knife - razor, pocket knife, or kitchen steak knife
  • Small Hand-saw (such as a drywall saw)
  • Side-cutter (for clipping zip-ties)
  • Cordless Drill and bits (5/16" and 3/4")
  • (Optional) Cordless Reciprocating saw
  • Circular Saw (for wood framing)
I found that this cardboard was so thick, it made sense just to go straight to power-tools. For example, I couldn't punch a hole in the cardboard with an awl. It was much easier simply to use a cordless drill to drill a hole instead.

To cut the cardboard, a steak knife works fine. A drywall saw worked very well. A cordless "Sawzall" type saw worked great, although noisier than the other options. My best pocket-knife worked best for straight cuts. A razor blade utility knife will NOT work as well as you think - the cardboard is just too thick.

Start thinking of the cardboard more like wood or drywall and you'll get a better sense of how to cut and build with it.

Also, remember how powerful glue can be. I only used glue on the ladder in this project, but wood glue can be amazingly powerful when used on strong cardboard. Consider gluing layers of cardboard anywhere you need extra strength. Triangles and arches can hold up nearly anything.

Project Cost: ZERO!
It didn't cost me a cent. The entire project was made from left-over cardboard, a few wood scraps, and fasteners I already had. When the clubhouse falls apart or isn't fun anymore, it will just be recycled.

Step 2: Stack Those Boxes!

To get started, I realized I had essentially two boxes. The cardboard that I pulled from the water container is really one box inside another - roughly a four foot cube.

The cardboard is over half an inch thick (and doubled up in some places) so it's very sturdy.

Since the one box is smaller than the other, and they are so sturdy, it gave me the idea that I could simply stack them up!

I folded all the flaps in, set down the larger one on level ground, and stacked the slightly smaller one on top of it.

To hold the top box in place, I zip-tied it. I quickly realized that a hand-punch was ineffective to make holes in this thick cardboard, so I used my cordless drill and 5/16ths" bit to drill holes where the zip-ties would go through. One hole through the top box and two through the bottom box gave me plenty of surface area and "grab" for the ties to go through.

I made sure that all the ties faced so that the retaining clip on it was on the outside, because they are still a little rough, and the girl was more likely to brush against one INSIDE the clubhouse.

After zip-ties were pulled tight, they were clipped off with a side-cutter.

Poof! Two-stories of cardboard boxes. Not very impressive yet. Time for doors and windows!

Step 3: Doors and Openings

Next, cut appropriate doors and openings in the boxes.

By "appropriate", I mostly mean that they are in the right place, and are the right size for whoever is using them. For a two-year-old, doors as small as one foot wide, by two feet tall work great. That's small enough to give that special secret hiding place feeling, but I can still fit through as well! (Sideways and crawling, but I can get in there if I have to.)

Use a your favorite knife or saw to cut a main door in the bottom. I also cut out a "porthole" and door-knob in the door. Save the cut-out to become the functioning door. Reattach it using loose loops of zip-ties as hinges. Now, the door can swing open and close.

On the second floor, cut a door for the ladder, and one for the slide. These will just stay as openings (who wants to open a door while standing on top of a ladder!?!)

You can also cut out hand-holds, windows, port-holes, peep-holes, air vents, and even a puppet theater! A series of properly-placed holes turns the side of the box into a climbing wall!

Step 4: Roof

With the two boxes that I had, the bottom one had a roof, but the top one didn't!

It was more of a four-sided "tube" than anything. No floor was no problem, as the roof of the lower box becomes the floor of the upper one, but NO ROOF?

I considered for a minute what I should do. I have some other salvaged materials around that I use for projects. I'm sure I would have had something else there I could have used. If the box had a top, it would have been moot as well. If I had extra cardboard, I could have built a roof from that as well.

But why do any of that when I already had EXACTLY the right thing for a roof!?

I've started doing a little gardening lately. And while I'm no master gardener, it still feels good to grow a little tiny bit of my own food. Towards that goal, I've been collecting materials to build cold-frames from. That includes a clear cover from a basement emergency exit.

My father is a remodeler, and somethings finds odd items getting thrown out from a remodel, or even great scrap material left over from new construction. In this case, there are sometimes fire-codes that require extra exits from basements. One style is sort of an extra-deep window well with a ladder. Over the top is a clear cover, roughly 4' square. My father gave me a discarded one to use for gardening season-extension.

By chance, it's EXACTLY the right size for the box. I simply set it on top, and the box fit exactly inside the lip on the clear plastic cover!

Instead of just having a dark upstairs box, or one with a pitched cardboard roof, the clubhouse has a fully formed and functional skylight!

Step 5: Cardboard Tube Ladder

At this point, I realized that I would need a ladder to get to the second story. I was also having so much fun using cardboard as a building material, that I wondered if there was a way to make a ladder also JUST FROM CARDBOARD!

As part of this packaging material, there were four extra-heavy cardboard tubes that ran vertically in the corners of the box. These aren't wimpy tubes like the middle of a paper towel roll, in fact, they would probably work well as baseball bats!

The tubes were about the right height for a ladder, so I decided that two of them would be the uprights, and I could cut the other two up to make the rungs.

I decided the rungs should be one foot wide, so I cut four one-foot sections from the tubes. I just used my power-saw, and sliced them off - just like cutting two-by-fours!

The next trick was figuring out how to connect the uprights with the rungs. I didn't have any tee material or other reinforcement handy. I decided that I could cut some scrap cardboard into a shape that would fit INSIDE the rung, and insert into a hole I would drill in the upright.

I marked the uprights with four evenly-spaced dots. That would be where I would drill 3/4" holes for my "cardboard pegs" to go in. I drilled four holes on each of the two uprights.

Next, I drew out the shape on scrap cardboard for the custom "peg" that would connect the rungs and uprights and cut them out. I needed eight total - one for each of the two sides of four rungs.

I then pushed the "pegs" into the holes in the uprights, slide the rungs on, and attached the other upright. I finished off the ladder by running a long screw sideways through the upright into the edge of the rung. I also ran a bead of hot glue around the end of the rung to help stabilize it to the upright. (Wood glue also works excellent on cardboard.)

To install the ladder, I leaned it against the clubhouse, and then ran a 3" screw through the inside top of each of the uprights. The head of the screw is then INSIDE the tube. The rest of the screw is buried inside the cardboard wall. Even though it's a 3" screw, it does NOT poke through to inside the clubhouse.

Step 6: Cardboard Slide

By now, I was imagining that nearly ANYTHING could be built from cardboard. But could I build a SLIDE?

I already had the ladder and second story. What was now needed is a fun and fast way to come back down.

I did decide AGAINST trying to ONLY use cardboard for the slide. I had a pair of 2x4s around that were about 5.5' long - which is about what I needed for the length of the slide.

I also had to figure out a way that the cardboard could be fastened down to the 2x4s, but WITHOUT any staples or screw-heads poking out. In roofing, shingles are put on starting at the bottom, with nails in only the top edge. The next shingle up then covers those fasteners. I would take the same approach to laying down the cardboard for the slide.

First, I built a simple rectangular frame from the 2x4s. I cut two cross-pieces about a foot wide and used wood screws to connect them all together.

I leaned the frame against the box, and then climbed inside with a few long wood-screws. I ran the screws through some scrap cardboard, through the wall, and into the top 2x4 of the frame.

The cover of the slide is two sheets of cardboard, each about 4' square. The lower one was run long, so that I had extra material to fold back and UNDER the wood frame. This would elevate the bottom of the slide to give it both the correct angle and make it so the child's feet hit the ground first while still in a sitting position.

The TOP of that sheet of cardboard got two short wood screws to hold it on. Those screws would then be covered by the next sheet of cardboard.

For the upper sheet of cardboard, I used one that already had a flap on it. I put the bend of the flap where the slide met the floor of the second story. I used 1.25" screws to attach the top flap down to the floor of the second story. I already had another piece of cardboard that would go over that as the finished floor. Again, I also checked the length of screws vs. the thickness of cardboard to make sure that none went all the way through and pose a hazard.

Due to the thickness of the flap, I had to notch away part of the wall of the second story to fit it through.

Next, I needed to fold up the cardboard to create sides for the slide.

From below, I ran my knife along the outside sides of the 2x4s to cut half-way through, so that the cardboard could be folded up. At the bottom of the slide, I made a through-cut on an angle from near the 2x4 out to the corner. When the sides fold up, that part will flare out to make an outward funnel shape. By zip-tying that in position, it will also hold the side rails up on a nice angle.

I folded the sides up, and while in that position, drilled holes for zip-ties, and zip-tied the upper and lower cardboard sheets together. Again, use the zip-ties so that the smooth side is in and the connector part is on the outside.

On the bottom of the slide. I drilled holes and zip-tied the "flares" in position to hold the sides up in the angled position. The sides really are not at 90 degrees, but are more than enough to keep a kid from sliding right off the side.

Step 7: Final Thoughts

Once the clubhouse, ladder, and slide are finished, there's just a few more things to do.

Take a look around the finished project for any fasteners or anything else the pokes out, is rough, or pointy. I made this so that all the zip-ties would face out and away from where children would play.

All screws used on the project were always in the back and bottom of the materials. The screws that held the ladder to the box were actually INSIDE the tubes. Any exposed screw-heads were covered by other cardboard.

Structural Integrity:
Make sure everything feels nice and solid. If there is anywhere that the two boxes, ladder, or slide don't fit together well, add another zip-tie, screw, or whatever is needed to make it solid. Cardboard is even stronger with multiple layers or folded into triangles.

Now, before anyone comments about cardboard not being strong enough to hold a child safely, please note:
  • The cardboard used originally held a 2000 lb. container, which could be stacked two high.
  • I climbed up the ladder, sat in the upstairs, and went down the slide. If all that can hold my 180 lbs, I think it will hold a 30 lb. child just fine!
This project was never designed to be water-proof. However, we are in the middle of a drought, and haven't had any measurable rain in over a month. Believe it or not, I should be able to move the entire clubhouse onto my covered porch if we have a rain-storm. Otherwise, I could also throw a tarp over it.
The structure will also be inspected if it ends up getting soaked in a rainstorm. Since the entire project was made from nothing but recycling and scrap materials, if it only lasted until the next rain-storm, that would be fine by me as well.

Attend your children:
Lastly, don't leave your children unattended. That's a good rule of thumb whether you are at the local park, the lake, or your own backyard.

Give the Cardboard Clubhouse a good trial run with your child. See that the doors are the right size. If you need another hand-hold at the top of the ladder, or another window somewhere, just add it! It's as easy as cutting another hole!

So, that's it. Good clean family fun! Mom and Dad can play with Princess and Sport in the backyard in this creative and inexpensive clubhouse.

Take care, and have fun!

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