Building with natural and recycled materials is the first principle when constructing an Earthship. Using recycled materials is often expressed by using what is lying around that has usually been tossed away into a landfill. Automobile tires are probably the signature item that everyone thinks of when Earthships are mentioned.
Why would you want to use tires? How about these two pictures for some motivation.
Humans have made so many tires now and after they wear out they end up in huge tire dumps because we don’t know what to do with them. That is starting to change as we are slowly finding ways to reuse tires, but building houses with them is just another item to add to that list. We have a LOT of tires lying around, billions of them. In fact there are now so many junk tires lying around this planet that you could almost call them a natural resource that we can use. It’s a funny way to think about it, but it might just stop you in your tracks to consider that we may have more junk tires on planet Earth than trees right now. That’s a disturbing thought.
Another natural resource used is dirt. Plain dirt, not pure sand or clay, but your run of the mill pile of dirt that is a mixture if things. You don’t want organic matter in your dirt, but other that that, most dirt will work.
And what do you do with that dirt, you may be asking? You pound it into the tires with a sledge hammer.
I’m not going to go into the process of how that works here, but if you want more details you can check out my other post on pounding tires.
Another really popular material used in building Earthships is beverage cans.
When Michael Reynolds was first experimenting back in the 1970’s with alternative building materials, he started with cans. This is long before Earthships had been conceived and also long before there was any such thing as recycling. Placing cans in concrete to build a wall means you need much less concrete to form the wall.
These days we do have recycling programs and beverage cans are recycled all the time. This may lead one to ask, why bother using cans when you can put them into the recycling and have them made into something new? First of all, cans are free and there are a lot of them. It’s difficult to pass up free building materials. Secondly, let’s consider a scenario where we take said cans and recycle the aluminum into some other building material, nails or flashing or whatever. The big difference between using the can as-is and using the remade building material is energy used. Using the can requires no additional energy, but there is a huge energy usage when recycling aluminum. By using the can you save that energy cost.
Not all recycled materials are purely functional. Glass bottles are used to create very decorative and amazing pieces of art. This is a bath tub in the Phoenix Earthship in the Greater World Community of Earthships down in Taos, NM.
Here is a bottle wall under construction at the Towers, a two storey Earthship down in Taos.
The glass bottles have their necks/tops cut off. You then find two bottoms that match and tape them together forming what we like to call a bottle brick. Similarly to the cans, these are placed in concrete. If you’re good, you plan it ahead of time, have the right colours and you can make some really awesome designs.
Some other natural and recycled materials being used are straw and clay for making adobe, cardboard for putting in the bottom of the tires so the dirt doesn’t fall out the bottom when you start pounding it with the sledgehammer and old pallet wood that is repurposed into making kitchen cabinets.
Earthships do use some conventional materials, like lumber, concrete, rebar and glass (windows) but the idea is to only use those things where necessary. What constitutes “necessary” will vary according to your design, location on the planet and what rules your municipality impose.
You may be wondering why go to all that trouble of pounding dirt into tires and putting cans into concrete. The answers to that and other questions will be handled in the Thermal/Solar Heating & Cooling post.
Stay tuned 🙂