Aluminum Cans | Can walls

Many of the walls inside the Earthship are made of concrete. These walls are considered partition walls, since they do not support the roof. They essentially act as dividers between rooms.

One unique feature of these walls is that recycled materials can be used as filler to create a lighter and more durable concrete wall. In the previous post, we explored the use of bottle bricks to create small portals of light into the interior spaces. Some partition walls are better as solid, flat surfaces. The filler in these walls is primarily aluminum cans. The cans are slightly crushed to keep them from sliding out of the concrete.

Because the cans are shorter than bottles, they can be covered over easily creating a smooth wall surface. Alternatively, the bottoms of the cans are sometimes used to create a mirrored mosaic pattern.


What about tin or steel cans? These cans do not work well for wall filler, because they are open on one end and therefore less supportive.

We will need several contractor bags full of aluminum cans.



Used Bottles & Jars | Bottle Bricks

The second most crucial wall building material is concrete.  What makes the concrete walls of the Earthship unique is the addition of recycled glass and plastic bottles in the form of bottle bricks.

Bottle bricks create a network of spaces to create a lighter, more durable wall that also lends itself to artistic expression and ambient natural lighting.

How are bottle bricks made?

Glass bottle bricks are made mostly with, you guessed it, beer bottles or other beverage bottles. The best bottles are straight-sided at least 4 inches from the bottom. Jars, wine and liquor bottles fitting this description also work well and add more design options.  The bottles are cut 4 inches from the bottom. The bottom part is washed and let dry to be used for bricks and the top part is recycled.

After the bottoms dry, two (2) of the bottoms are placed cut-side together and duct taped around the seam where they meet.  This is a completed bottle brick!

Plastic bottles are a little bit easier, only one bottle is cut and placed over another intact bottle and then taped. The bottoms of these bottles are often more interesting shaped and lend themselves well to making flower patterns (as seen in the featured photo above).

Here’s a short video about how the bottles are cut and put together Cutting a bottle brick.

Here is a longer in-depth instructional video Bottle Wall Building.

Used Tires | Rammed-Earth Blocks

Used tires are the most crucial component of Earthship construction.

Tires are pounded full of dirt to create rammed-earth blocks. Building the massive retaining wall of tires is the first phase of 300px-earthship_plan_with_vertically_glazed_southern_wall-svgconstruction. Work on the tire wall starts after the ground is leveled and the layout has been marked out with string lines as described in this video Tire layout.

The tire layout is shown here in this floor plan.

The tires must be gathered from various sources and stored onsite before the build starts. Automotive shops often will have large quantities of used tires that they haven’t taken to the dump. Since they have to pay loads of money to have them disposed of, automotive shops will often just give them to you (if they are really grateful for the cost savings, they might even deliver them).

How many tires are needed?

Hundreds to thousands. The exact number depends on the outside dimensions of the Earthship. Larger spaces require more tires. Smaller spaces use less.

Here’s how I estimated the number of tires we will need for our 1400 sq. ft. home:

Our home footprint will be 20 ft deep x 70 ft long. The total length of the tire wall includes two (2) tapered ends, two (2) side walls and the back wall. (I estimated the tapered ends to be 10′ each). That’s 20′ for the ends, 40′ for the side walls and 70′ for the back or 150′ total.  150′ x 12″= 1,80o ft.  Divide that by the standard 15″ tire diameter to get 120 tires per layer (also called a course). There are 10 courses total.

That is 1,200 tires for a 1,400 sq ft home. 

Which tires are best?

First, we need to discuss some tire numbers. Reading tire sizes

The tire’s sidewall will be printed with a size in this format:

               P215/65R15 95H

The numbers we are most interested in are shown in RED

The first number is the tire width (millimeters) from tire from sidewall to sidewall. 

The second number is the wheel diameter (inches) from tread to tread across the center of the circle.  

A tire wall starts with larger tires at the bottom and ends with smaller ones on top.

The tires also need to be completely intact or else they will burst when pounded.

We need sizes:  205/15    215/15    225/ 15   235/15    235/16


What is an Earthship anyway?

Earthship is the term for a unique type of eco-friendly and sustainably home that interfaces with natural phenomenon to care for its inhabitants.  Earthships provide these six basic survival needs and they do it all without a single utility connection:

Shelter / Comfort – thermal mass and passive solar heating

Water – roof water catchment system

Food – indoor planters filter gray water (for reuse in toilets)

Energy – solar panels and wind turbines for power generation

Recycling – reuse materials available in modern society (tires, bottles, cans, cardboard)

Sanitation – onsite waste treatment via septic system with optional outdoor planter

Join us as we build an Earthship: A self-contained life-sustaining vessel for surviving here on planet Earth.