What to build with cardboard?

[Fru-Gal]

I have some extra thick cardboard in a giant bike box that my offspring received and thoughtfully left behind in the garage. /s

I'm searching for ideas of things to make with it. Furniture, small cases, maybe very large planter pots with the cardboard as the structure then covered with cement or stucco? Suggestions?

[AccidentialMustache]

I turned standing desk desk-top boxes (which ships with foam padding...) into large insulating slabs that I can stick in front of the fireplaces in winter for some extra insulation. I only kept a couple boxes, but I raided the full office's worth of foam, so that I could fill the boxes I turned them into. YMMV on ways to fill it with insulation, but if it'll tape shut then foam peanuts are always an option.

DW uses cardboard in the garden to be able to kill grass/weeds. Lay it down, especially in fall, weight down with rock/brick and stuff will be dead in the spring so it is easier to convert.

[uniwelder]

A giant butterfly or dragonfly.  The two big flat sides of the box become wings and the narrow long section can be the body. 

[Sanitary Stache]

My kids make swords shields and life size cutouts of their made up graphic novel characters.

[Dicey]

I once had a book about making furniture from cardboard. It's probably out of print now, but you might find it on the used market. It was sort of hippie-ish but it had some pretty good ideas. Something like this:

https://www.amazon.com/Make-Furniture-Cardboard-George-Delucenay/dp/0811725480

There's also a lovely YouTube rabbit hole on the subject. Have fun!

[bacchi]

Cat maze!

[techwiz]

I did this project years ago with my daughter, and it is still working connected to our TV. 

https://discover.hubpages.com/art/make-this-powerful-hdtv-antenna-out-of-cardboard

[Fru-Gal]

Now I’m getting excited! I googled “French cardboard furniture technique” and came up with some amazing examples. Ironically, I had to disassemble an old store-bought couch a few months ago and most of it was cardboard!

When my kids were little we made all sorts of play houses and mazes and car ramps from cardboard. One of my kids made an entire miniature city.

Thanks for these ideas, they are great & feel free to share more!

[lhamo]

If you run out of uses for it, try to find a gardener -- plain brown cardboard makes great material for sheet mulching.  I have used it both to block weeds under wood-chipped path areas and under new beds where I want to minimize weed growth (top with 4-6" of compost).

I learned a couple of years ago that when I have a gardening project I need cardboard for I can pretty easily get a bunch by posting on Buy Nothing/Next Door, or if that doesn't generate enough I just go out early on recycling day and grab a bunch that is waiting for pickup.