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.