Make a Weatherproof Cardboard Box Fort

Who doesn’t love a good cardboard box fort? Me, me, I do! Hours of entertainment that comes at a zero dollar price tag? Yes, please. Because we live in New England and endure some looooong, cold winters, we’ve gotten pretty creative with our cardboard box fun on days when it’s too cold to go outside. But even now that the frigid temperatures, snow and ice are long forgotten, my daughter still loves to play in box forts. Box forts are a fun way to change things up in the backyard without dropping a hefty chunk of cash on a playhouse. Unfortunately, a few of our box creations have suffered a sad, soggy fate when left out overnight to sag and collapse after a heavy dew or a surprise rain shower.

Enter Rust-Oleum’s newest product. The moment I heard about Rust-Oleum NeverWet, I started imagining all of the things I wanted to waterproof. I won’t even go into the list of things I dreamed up — it’s long and slightly ridiculous. (Let’s just say my husband and I had an entire conversation about treating our brick walkway just to see if we could skip out on shoveling next winter.) Once I came back to reality, I realized that Rust-Oleum NeverWet might just be the product to save our summer cardboard box forts from a soggy fate.

Let me tell you, this stuff was crazy amazing. I did a test on a scrap piece of cardboard and could not believe how cool it was to see the water bead up and slide right off. This stuff is BANANAS.

The water beads up and slides right off. Coolest thing EVER.

Once I finished up the box fort and was ready to test it out, of course the forecast called for only blisteringly hot, sunny and cloud-free days. We decided to create a man-made test by using the box fort as a sprinkler shelter. Our daughter has a love/hate relationship with the sprinkler — she loves the idea of it, but the cold water is a little shocking and usually her first pass through is her only one. We thought giving her a nice, dry place to hang out and get a little wet might be the perfect compromise. HUGE success. The cardboard box fort is still going strong a week and a half later, and it’s become the favorite backyard hot spot. The swing set looks on longingly. At this rate, the box fort might only go into retirement when our daughter outgrows it.

Here’s my step-by-step guide on how to build your own cardboard box fort. Go find Rust-Oleum NeverWet. Trust me. Not just for box forts, but for outdoor linens, paver stones, water-play art projects, and (my next test) weatherproof suede ballet flats. Rust-Oleum NeverWet to the rescue!

This post is brought to you by Rust-Oleum NeverWet — “You’ve never seen water behave this way!”


Step 1

 Open GalleryWe have a stockpile of cardboard boxes in the basement. This particular box held a chair from IKEA and was the perfect size to use for a toddler-sized fort.

Step 2

 Open GalleryI wanted to create a pitched roof that was high enough to allow my 36-inch-tall daughter to stand up inside the fort, so I first cut two of the longer flaps off the bottom of the box to use to extend the roof. Then I marked the shorter of the flaps on the top of the box to cut — they become the support for the roof flaps.

Step 3

 Open Gallery

Here are the cut flaps.

Step 4

 Open GalleryI used a few pins I had on hand to secure the flaps attached to the box to the support flaps I’d just cut so that I could tape them up with my old standby, Duck Tape. (I did glam it up a little with one of the new bright colors for this project!)

Step 5

 Open GalleryThis is where I used those two flaps I’d cut from the bottom of the box in step 2. I taped them together to form the inverted V of the roof, then taped each side to the lower flaps I’d already secured to the support flaps.

Step 6

 Open GalleryA good fort has to have windows for peeking. I taped off all of the cut edges to protect them from water and was ready to move on to the spraying.

Step 7

 Open GalleryI brought my box fort outside to spray. I set it up on a board to protect the grass and got down to business.

Step 8

 Open GalleryRust-Oleum NeverWet is a two-step treatment and was super easy to apply. Step 1 is the base coat. You spray it on side to side, in a light and even coat, and then go over it top to bottom in another light and even coat.

Step 9

 Open GalleryAfter I applied Step 1, I gave my box fort 30 minutes to dry before moving on to Step 2.

Step 10

 Open GalleryStep 2 is the same process — side to side, then top to bottom. Light, even coats.

Step 11

 Open Gallery

And then, if you’re like me, you realize you completely forgot to treat the bottom first like you’d planned, because you were so giddy to give this stuff a test drive. No harm, no foul. Just treat the bottom with Step 1, allow to dry 30 minutes, and treat with Step 2. No one will ever be the wiser. Unless you write about it on DIYNetwork. In which case, a whole lot of people will know what a silly girl you are. Oh well. Like that was some big secret anyway.



  • Craft knife or scissors
  • Respirator mask
About Ellen Foord 


A tight budget has never stopped Ellen Foord from creating a beautiful, modern, creative home and treating every day as one of life's smaller celebrations. A freelance writer and ...

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16 Responses

  1. Jack says:

    Why not to do it from old flooring leftovers or at least wood like this guys:
    Jacks Carpet

  2. MarcioWilges says:

    That has got to be the most incredible stuff I have ever seen on the internet. Who knew such a thing exists? This means that you can transform anything and everything into a waterproof product! How ingenious is that? I have always thought there is no way I can ever salvage my moving boxes because of the monsoon weather we often experience here where I stay. However, with this magic potion, I believe that fact might just change for the better.

  3. Cathy says:

    Can you spray paint over it? I'm making those big paper mâché letters for our Christmas outdoor display and wanted to find something to waterproof them before I spray paint them a color. Thanks!

  4. Marilyn Ross says:

    I have a dog in my house and I want to make a waterproof cardboard because they are not so much expensive and also seem attractive. The steps you share are help for limo hire to make this cardboard but I don't know where I can purchase this waterproof material. Please post proper information about this spray.

  5. Wow! Very easy to follow, interesting and useful tutorial you have shared. The product you recommended here is pretty impressive in looking and I hope Wedding Car Hire will work as same. Now people can easily make a card box fort for their children with no cost which will be also useful rain.

  6. Sarah says:

    Yikes, I dunno if I want that stuff around my child. I just looked at the MSDS for it. Sounds pretty harmful in many aspects:

  7. Colten Gilberto says:

    Essay witting service provides its clients an excellent service. You can avail the service for purchase custom research paper and other academic writing services at all educational levels. We grantee you a highly satisfied work by us.

  8. Making things from cardboard is a fun activity but I never ever have crossed a brilliant idea like this before. It is pretty creative and card box fun on days when it is too cold to go outside. Thanks for sharing the idea and procedure it sounds fun and useful.

  9. It is good to read your post and I am so happy to know about water proofing.

  10. Audrey Greenwood says:

    There are quite a lot of this new-fangled water-phobic sprays and douses available online these days huh! I've seen one recently that are able to make my booties and leather shoes water-phobic too! Being a director at a moving box company though, this idea could really be a really good tip for some of my customers who are worried about moving in the rain and it looks like it might be worth a look at now that it's gaining more hype!

  11. novice says:

    Hello, How did you avoid the white milky surface or is it just not showing up in the pictures? Most reviews comment that although this is awesome at first it wears off quickly especially if there is contact or exposure to sun. Did you experience this? Is the surface rough and or tacky?

  12. Jeannie says:

    Love the Idea! I have a 4 year old that would love it to pieces! Thanks for the great idea. I know after we move and get settled in, that will be the first fun project I will do with my kids.

    • Minnow + Co says:

      Jeannie – my daughter is STILL playing in her cardboard box fort! It's held up so well through a LOT of use and more than a couple summer storms here in New England! Thanks!

  13. Lynn says:

    Sounds great!! I'll bet that would work for a camping structure as well—Especially if you take your dogs camping!! P
    ut the crates inside and they will be safe from wind and rain!!

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