Fold-up Playhouse

This Instructable is a variation of  https://www.instructables.com/id/Emergency-Shelter-II-from-Coroplast/.  In fact, it is the same structure you see in the Shelter II photos cut down to a size that will fit in my car when folded up.  Consequently, the comments in Shelter II and https://www.instructables.com/id/Helter-Shelter/ also apply here.  The design goals still include one piece fold out construction, mass producability, and inherent rain water shedding without extra tape or sealing.  This one is used as a playhouse and has been outside in Galveston, Texas for three months.  It is easy to move around for mowing the grass, or storing away for hurricanes.   

Step 1: Materials

Coroplast - 5 sheets, 4mm thick, 4 x 10 feet, white (Regal Plastics, Austin, Tx)
acetone (Home Depot)
duct tape - white, 2.88 or wider, 60 feet (Home Depot)
binder clips - 8, large
plumbing parts - 7 sets of male/female adaptors (Breed's Hardware)
PVC pipe -  1/2 inch, 17 feet (Home Depot)
hose clamps - four 2.5 inch (Home Depot)
stakes (Home Depot)
cord - 3 feet (Walmart)

Step 2: Tools

Sharpie markers
48 inch metal ruler
awl
Utility knife with adjustable depth
Dremel with sheet rock cutting tool and attachment for adjusting depth of cut
1-1/4 inch hole drill

Step 3: The Pattern

Here is the pattern for the entire structure.  This pattern will be achieved by cutting, scoring, and taping together the 4 1/2 sheets of Coroplast.  It is a good idea to experiment with the structure by printing out the pattern on a piece of paper or card stock.  Then practice folding and unfolding the structure as shown in the diagrams.  You may discover alternative designs that are better suited to your purposes.  For example, seven or six sides instead of eight.  Experiment with it!   Notice how the end panels overlap so the entire roof will shed rain water to the outside of the structure. 

Step 4: Drawing the Pattern

Draw these patterns on the Coroplast sheets; four sheets for the top pattern in the diagram, and one for the bottom.  The sheets of Coroplast are the same on both sides, so it does not matter which side you choose to draw on.  To cut down on the amount of tedious measuring and drawing, I used one sheet as a pattern for the rest, by stacking sheets under the one that is already drawn and marking the outside endpoints with a Sharpie marker, and the inside points by sticking a hole through the sheets with a sharp tool like an awl or nail.  Use acetone on a rag to erase marker errors.

Note: Some of the photos are from another project, but the same principles apply.

Step 5: Cutting Out the Pattern

Remove material that is not needed by cutting around the perimeter of the pattern on each Coroplast sheet with a utility knife or a pair of heavy duty scissors.  If you use the utility knife, putting a piece of scrap material or cardboard under the piece being cut may be helpful.

Step 6: Scoring the Fold Lines

Scoring the sheets makes them easier to fold along straight lines.  By scoring, I mean to cut through the first layer of one side, leaving the opposite side intact.  Adjust the utility knife blade to a depth of around 2mm.  Make test cuts on scrap material to practice and see how deep the cut needs to be for a good bend in the material.  The metal ruler helps as a guide when cutting at a diagonal across the sheet.  Also the orientation of the ruler with respect to the cut and the internal ribs of the Coroplast is important.  One orientation pushes the blade against the ruler (good);  the other orientation pushes the blade away from the ruler (bad).  Experiment to find the method that works best for you. 

The red lines in the figure are scored on the outside (the side with the drawn lines).  The green line is scored on the inside.  The blue line is cut all the way through.  Bend all the scored lines to loosen them up.

Step 7: Tape the Sheets Together

Tape the sheets together with tape on the inside and the outside.  Leave 1/4 inch space between the sheets so the taped joints will fold easily.  Now you are ready to set it up!

Step 8: Setup

Set up as shown in the diagram steps 3 - 6.  The bottom floor flaps are not shown in this diagram, but they fold to the inside of the structure.  Also missing the overlap section in this diagram, which may overlap on the inside or the outside.  Use 8 binder clips to secure the structure at the top as shown in the 2nd diagram.  Tape the overlapped panel on the outside to secure it until the PVC bolts are installed in the next step.

Step 9: PVC "bolts"

PVC pipe fittings make good bolts to secure the walls.  The trick is to find fittings that work like bolts and tighten up enough to compress the Coroplast securely between the "bearing surfaces" of the bolt and nut.   Since pipe fittings have tapered threads, not all of them will screw together closely enough to make this work.  Go to a store with lots of plumbing parts to try them out before buying.  These male/female adapters from a hardware store worked for me.  They work perfectly with a 1 1/4 inch hole cut in the Coroplast.

With the overlapped wall sections lined up and secured with tape, drill holes through the overlapped walls as shown in the 2nd diagram.  Insert the PVC bolts and tighten.  This action is easier with someone on the inside and the outside, since the door shown in photos is not cut yet.

Step 10: Doors and Windows

Cut doors and window wherever you want them.  This one has a door cut in the overlapped section.  The Dremel is good for cutting round windows.  Use a large bowl for a template to cut around.  Put scarp material underneath so you don't cut into the floor.  I used a smaller PVC bolt for the doorknob.

Step 11: Base Ring

The base ring give more stability to the base of the structure.  It is sized to just fit inside, on top of the floor flaps.  Cut enough PVC pipe to go around the inside.  The circumference is a little smaller than 8 sides x 2 feet/side = 16 feet.  Add a foot for overlap.  Connect the PVC pipe in a ring held together with the 4 hose clamps.  Insert the base ring under the structure and then on top of the floor flaps.   Loosening the hose clamps to make final adjustments to the circumference of the ring and then retightening them.

Step 12: Stake It Down

Stake it down or it will blow over.  Cut small holes at several places around the base.  Loop cord in each hole, around the base ring, and back out the hole.  Drive stakes into the ground and tie each cord to a stake. 

Step 13: All Done!

Paint it if you want.  Or let the kids do it.