Things I Learned: Can/Bottle Walls
21. Mar, 2009 
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Bottle Brick Bathroom, originally uploaded by Earthship Kirsten
If you’ve been following my Earthships adventure, you know that it is actually possible to build houses using garbage. Can and bottle walls—literally walls made out of mud or cement, with cans or bottles set like bricks—are one of Mike Reynolds‘ time-tested innovations, a building technique that can have amazingly artistic results.
Can/bottle walls look and act like normal walls, except that they can’t bear heavy loads. They’re much, MUCH faster to build than tire walls, but don’t have the benefit of thermal mass. In Earthships, they’re used for room dividers, garden walls, and other non-load-bearing verticals. You can literally learn how to make one in five minutes; they’re cheap as free and extremely easy to put up. So, here’s how!
1. Get Prepped.
- You’ll need:
- For a can wall: a whole crapload of not-too-crushed cans
- For a bottle wall: a bunch of “bottle bricks” created by cutting bottles with a wet tile saw and taping them together (just make sure they’re the width you want your wall to be)
- mud or cement, a nice sticky consistency that balls up in your hand but doesn’t crumble. (cement is better for outdoor walls, but mud costs $0)
- rubber gloves to protect your pretty pitties.
If you want your wall to be extra stable, you should pour a footing or pound some tires; any wall needs a solid base or it’ll just, you know, fall over. So don’t try to build a wall on sand, please.
2. Put some mud.
If you’re building this wall on concrete/cement, wet the base first to help the new material bond. If you’re not, just go ahead & start.
Grab a handful of mud, and put it somewhere. CONGRATULATIONS YOU’RE BUILDING!
Make a nice thick layer of mud; you don’t want any can or bottle to touch anything except the mushy stuff.
You’ll get a feel pretty quickly for how high you can pile cement/mud, but eventually you’ll have to let it dry for a while, and move on to another section. It ain’t rocket science.
3. Put some cans (or bottles).
Bottles are generally used for their artistic value—those amazing stained-glass designs—but cans are far more plentiful and easy to work with. Therefore, most walls start with a base of cans, which can be left exposed or plastered over to look like a normal wall.
Take your cans and make a small crimp along one side, which will keep them from rolling once you’ve placed them. Put them, crimp-side-down, into the mud. You don’t need to smash ‘em in there; just place them solidly enough that they won’t easily blow away. Leave a couple-few inches between each can: they should never touch each other.
The concept here is that cans have a strong structure which resists crushing. They can act like bricks, and you are laying them in mortar. The cans will provide a framework around which the mud/cement forms. Lay them in a staggered grid, just like bricks, and they create a truly strong wall.
Cans and bottles are always laid with the solid end toward the exterior. This protects the interior from the elements: no water can get in, preventing damage. And obviously, it looks better this way.
Ted w/Phoenix Bottles, originally uploaded by Earthship Kirsten
4. Finish it.
Once your wall is built, it’s a simple matter of plastering over the cans and bottles. You can cover them completely to create the appearance of a normal wall, or leave the ends exposed for artistic detail. Cement or natural plaster can be used, depending on your personal taste and the placement of the wall.
This is Ted, working on exterior walls at the Phoenix Earthship. As you can see, he’s got most of his weight resting on a bottle arch, the Phoenix’s entryway. For some, it might be hard to believe that these walls are strong enough to hold up, but here’s your proof: they’re built to last.
In my few weeks here, I’ve spent time in some of the older, experimental buildings from Mike Reynolds’ past work, and I can tell you for sure that can/bottle walls are strong, and sturdy, and withstand the test of time. But don’t take my word for it; next time you’ve got a building project, try using can/bottle walls and see for yourself!
Other techniques.
As you can see, this wall fills the spaces between vigas (roof beams). Nails are driven into the vigas at random angles, giving the cement something to grip. This “porcupining” ensures a strong bond, making it nearly impossible to remove the cement.
This is a can-built form for a concrete bond beam on one of the new, experimental structures. This structure is going to be two stories tall, and will have heavy vigas attached at this level. The cans won’t be supporting any weight, but will add structural integrity to a layer of concrete which will be poured into this gap. The concrete will set around rebar stakes pounded into the tire wall. Vigas will be attached after the concrete dries, so the weight will rest evenly on the tire wall.
This can/bottle wall will be two stories high; it will encircle the experimental Hut structure (the tire wall visible in this photo), and the space between the two walls will be filled with pumice for insulation. Since the wall is two stories and free-standing, and since the glass is not used for decorative purposes, we’re laying a double row of bottles that haven’t been cut. The bottles will be plastered over, but over time the plaster will wash away and the bottle ends will be exposed. Even though they won’t give the “stained glass” effect of other bottle walls, they’ll still add texture and design to the wall.
As you can see, this wall was begun with a course (two, where the ground is low) of tires, followed by three courses of cement and cans, then mud and bottles. It’s probably about a foot thick.
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