Cardboard Wall Is Surprisingly Well Built

We all built cardboard forts when we were kids. [Paintingcook] has taken it into adulthood with a hand built cardboard wall. He and his wife leased a loft apartment. Lofts are great — one giant space to work with. Plans changed a bit when they found out they had a baby on the way. A single living, working, and sleeping space definitely wouldn’t be good for a newborn, so the couple set about separating a section of the room with a wall.

Sheetrock and steel or wood lumber would be the normal path here. They instead decided to recycle their cardboard moving boxes into a wall. The boxes were formed into box beams, which created the framework of the wall. The two pillars were boxed in and incorporated into the wall itself. The skin of the wall is a random patchwork of cardboard pieces. Most of the construction is completed with 3/8 ” screws and masking tape. Tape won’t last forever, but this is a temporary wall after all.

You might be wondering about fire hazards — sure, cardboard burns more readily than gypsum board, but the apartment is outfitted with sprinklers, which should help on this front. A few commenters on [Paintingcook’s] Reddit thread asked about formaldehyde and other gasses emitting from the cardboard. Turns out he’s an inorganic chemist by trade. He says any outgassing happens shortly after the cardboard is manufactured. It should be safe for the baby.

Cardboard is a great material to work in. You can build anything from robots to computers to guns with it. So get hop the couch, grab that Amazon box, and get hacking!

48 thoughts on “Cardboard Wall Is Surprisingly Well Built

  1. I built a darkroom when I was a teenager with cardboard walls. It worked pretty well. You obviously could not hang anything on them, not lean up against them, nor were they near soundproof, but they worked great for keeping the light out, and required more skill with duct tape than carpentry.

          1. You can also theoretically jump over boxes and they are more localized than a wall which when on fire blocks the entire room.

            Still, if they have smoke detectors AND keep the batteries updated they are ahead of the game compared to average according to statistical reports on the spread and powering of smoke detectors in the US.

    1. It could be painted with ‘water glass’ (sodium silicate) a clear aqueous solution of a common salt. This used to be used as a fire retardant. I recall in an old, old hobbies magazine there was an article on how to make prank matches that would flare up and then die out, to the mystification of the user. This was done by simply dipping the match (except the head) into the water glass and letting it dry, forming a near-invisible fire resistant coating.

      The IKEA LACK bedside/occasional table is constructed of cardboard internally. I suppose it would be treated with some sort of retardant.

    2. The trick is to build the cardboard wall sturdy enough to stand but weak enough for you to in case of fire JUMPSMASH right through it, cardboard ablaze, action movie style.

  2. Re: fire hazard. . .For several years in October we were a part of constructing a huge totally dark multi-level one way in-one way out cardboard (refrigerator boxes) crawl-through maze for young kids in our city. Rough dimensions were around 100 x 35 with parts 20 feet off the floor. Our local fire department gave us instructions on how to make the cardboard flame retardant as well as other safety features. We used a spray on liquid. I don’t remember the name of the product, but we tested it (outside) and it worked quite well at suppressing our attempts to make the cardboard burn. Just search for “fire retardant spray for paper”.

    1. Something makes me think that starting with a paper product that is thin with a large surface area (including internal fluting) and lots of air pockets and then trying to fire proof it is probably the less than ideal approach to take. What is the fire retardant made out of would be another potential issue to consider, especially around young kids.

    1. I love how the world went from SAVE THE TREES to KILL THE TREES, Plastic is bad mentality. I always wondered why the tree huggers where worried about trees that could grow back. in California our fires destroy more trees then we would if we had just cut them down for paper/etc…

      Now we have paper bags again at grocery stores! yah kill the trees!!!

      Not sure if im on board with paper clothes….ill stay with cotton. it is also grown and GREEN.

      1. You have to be very careful when laughing at your opponents, especially if you have not even tried to understand them.

        If you have seen a real forrest and compare it to the places where we produce wood then I think it’s easier to understand why we have tree huggers. Even comparing fires with the wood industry is a good indication of the destruction wood production brings.

        1. Plastic grocery bags are made from ethane, which is removed from natural gas so it won’t burn too hot. Making bags is much better than releasing it in a flare. Is it a surprise that California’s policies don’t pass the smell test?

  3. When we unbox a piano it’s box is third world housing, second… wait sometimes first (America) world housing. Triple ply cross laid. Back in the ’80’s they came in mahogany wood crates, the rape of Indonesia’s forests under Sukarno.

    Back in ’70 I found a box that held one of those electric brooms, long and slim. I cut it in half to make two identical boxes, closed cut end flaps with glue. I had two car speakers 6X9 with grills, to which made two of the most satisfying speakers I have known. One is still hanging around somewhere here. Light, ported, hard to damage if dropped, good bass, back when they were efficient just not able to handle what was not available in a car back then.

    My high school shop teacher was impressed when he brought in a cassette of a drag racer he was involved with and I played it thru one of these from a mono dictation recorder running on battery with the bass port setting over a hole in the radiator cover giving even more bass for the whole class.

    1. Same reason why a split wooden log isn’t a fire hazard, but the same log pulverized into sawdust is. You take the contents out and leave a bunch of empty cardboard boxes laying around, and it’s just dry tinder waiting for a flame. More exposed surface area, faster reactions – goes up in flames in a second.

  4. My company uses cardboard boxes for shipment of products, like so many do. We were looking for alternative suppliers and pricing, oddly, this is one area companies rarely look when trying to reduce cost. I was amazed to learn all the different standards set for simple boxes. It made sense but its something that people rarely think about when choosing a box to use for storage, shipping and handling.

  5. Too many snowflake safety kiddies wrecking the comments sections on HaD. So what if cardboard is a fire hazard? What are the chances of something igniting it? Do you let your toddlers play with matches?

    The pile of papers all over your desk is a fire hazard too, especially if you smoke.

      1. “Many”? I doubt it. Besides, anyone with the savvy to build these cardboard walls in a way that won’t immediately collapse is surely smart enough to not leave matches around. Otherwise… well, Darwin must be fed.

          1. Gypsum is incredibly fire resistant. The paper (likely treated but for argument a say it is not) is nothing compared to gypsum natural fire resistant. It’s cheaper as well as the best option for modern residential type building. Look it up it’s actually kinda cool/ interesting history. I currently live in a house with plaster walls… it’s annoying for many reasons.

            That aside. Im sure this family will not live like this for long enough to even have to worry. Babies can’t effectively crawl for at least 18 months let alone have the dexterity to mess with matches/lighter. Not to mention that lightbulbs almost never get hot enough to start a fire since incandescent bulbs are all but obsolete so after almost 2 years the child won’t be knocking over any lamps.

            It’s just dumb that people say things without logic just to be negative.
            This post isn’t a recommendation it’s an isolated case. Saying if you really need to you could potentially do this too.

  6. Meh, if I were going to do this, I probably would have built a temp wall out of standard 2 x 4 s and sheet rock. It really wouldn’t have been much more effort and probably would look better.

    I’m no snowflake (Ironically I find people who complain about snowflakes tend to be some of the easiest to butt hurt themselves). I don’t however, think it’s a bad thing to point out issues the original builder might not have thought of. It might help anyone else who might be thinking of doing the same.

    For instance cardboard IS a fire hazard, whether it’s built as a wall or being used as intended and stacked up in all the storage areas of your house, it’s fuel for a fire. Whether you should live in fear of your house going up in flames, that’s up to the individual person. But knowing that having stacks of cardboard or news papers, or what have you lying around your house could mean, if a fire breaks out, you could potentially allow the fire to travel faster through your home. The more fuel for the fire, the more likely and faster the fire will spread.

    Surviving a house fire is about having enough time to escape and that is why we have learned to build our homes in a manner that slows fire and prevent as much smoke (which is the real killer in a house fire) and toxic fumes from spreading through out the house. Things like fire breaks in the wall and using plenum rated wiring if you are running it though HVAC, are things we have.

    Just some things to consider when building stuff like this in your home.

  7. Your lumber-and-drywall project would almost certainly scratch up that nice fake hardwood floor and the paint on the walls and ceiling, whereas the cardboard could be held in placing with non-damaging painter’s tape (the blue stuff). Remember, this is a rental.

    1. Leave painter’s tape on a wall long enough, and I mean the kind that will actually stick to cardboard enough to hold it in place and also not peel off on it’s own, and then talk to me about non-damaging. Any semi long-term sun exposure will also hasten the hardening that I’m implying. You will be doing some paint touch-ups, even if you are lucky and avoid the use of a scraper to remove the hardened tap.

      Not saying 2×4 and drywall is easier by any means, but you could face the floor contact side with felt, then lag bolt the top and ends of the framing to the ceiling and wall studs respectively with careful use of a stud finder, ruler and drill. Require s a bit more tooling than cardboard but could more easily be insulated with flame retardant insulation to sound proof the baby’s sleeping area as well, which is more than most interior rooms can boast three days. Or just use really long nails instead of lag bolts. Harder to remove perhaps, but fast and cheap. Either way, it’d be predictable dry wall hole spackling at best and likely easier to ensure full deposit is returned.

      Or simp my float the entire wall setup with some bracing to act as feet…Think portable office partitions. Heck, a ceiling mounted track to use the hanging type of those could also be used.

      Anyway, props on the cardboard use. Just don’t agree with others that a temporary 2×4 wall is unreasonably harder. More expensive, but not harder.

  8. So much safety troll! Many comments on fire safety, none on efficacy. The main purpose of putting the baby in a separate room is sound – not only for the haggard parents, but for the baby (it depends on the baby, but many are awakened by loud noises, and especially by the voices of their parents, who are their main source of food, comfort and entertainment – see also “FOMO”). This is partly why the white-noise-generator-and-baby-monitor setup is so common, to drown out “interesting” sounds on the baby end and provide a one-way sound channel. It would be interesting to see if the cardboard wall delivers any significant benefit in this area. It will at least block light so the grownups don’t have to sit in a darkened tomb all night with the Netflix off (incidentally, this leads to more babies).

  9. Re: fire hazard: I’m guessing most people in shouting “fire hazard” have never attempted to start an actual fire with cardboard as tinder. Having been poor (young parent during recession) in a rural area, let me tell you. I had access to free firewood and a fireplace, owned as axe. I did NOT have money for things like accelerants or easy start tinder. Not even newspaper. Boxes, however, can almost always be had for free.
    HOWEVER, It takes A LOT OF WORK to start a fire with cardboard. That’s if you’re setting it ablaze on purpose. You have to peel it apart and then shred it in order to start a fire with it. And curse. And pray.
    Sure, it will burn merrily if there is a preexisting fire tearing through the room, but let’s face facts here. So will their books, furniture, walls, etc.

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