Earthship Tires and the Off-gassing Issue

DSC05906 (Medium) The major structure and performance of the earthship is encompassed in the design element termed with a “U” in the previous chapters. Modules are constructed in the shape for reasons already described…  the primary building block that meets all of the … requirements… is a rubber automobile tire rammed with packed earth. The rubber (sometimes steel belted) automobile tire is indigenous all over the world as a “natural resource”. Every city is a natural supplier of this item. It can be “harvested” with absolutely no technical devices are energy other than to human hands to pick it up and throw it into a pickup truck. It is readily available without the energy and economic impact of shipping to every potential building site… The rubber automobile tire can be used as found without any modification. The process of reining them full of densely packed earth is achieved with simple human labor and can be done with whatever type of earth is available on the building site.”
-  Earthship Volume 1

EB uses tires because they believe that tires are a plentiful resource which they are recycling to keep out of landfills. And they are not incorrect in their assessment of the very real presence of tires as an environmental concern. According to the EPA report, “Scrap Tires: Handbook on Recycling Applications and Management for the U.S. and Mexico” in one year’s worth of calculations alone, 275 million tires were already stockpiled in the United States, and approximately 290 million new scrap tires were generated. There’s a very real need to address this reality.

They state, “Many new materials are unhealthy to be around. Unfortunately, this is not discovered until they have been used for years.”  Yet they fail to address the very real concerns of health which rise from the use of their own materials – tires especially.

Many earthship fans call upon our office to ask the question, “Is there really an issue with off-gassing?” The answer is simply… we aren’t sure. We do not assert that we have smelled any vapors in the many earthship homes we have visited. We have not. But we ARE a historic preservation firm in addition to our role helping design sustainable homes and communities, and we deal with lead based paint and asbestos in our day-to-day work. We are aware of a great many people (and resulting lawsuits) in modern times too whose cheap gypsum board walls imported from China have made them sick. And we know that you can't smell any of the contaminants in any of these applications. These products have been banned. Because they are toxic whether you can smell them or not. The price paid for that knowledge was tens of thousands of lives, because they didn't test the materials before approving them for use in construction. We don't want to see anyone repeat those same mistakes, least of all... you.

These are very real human health issues we are talking about here.

EB would have you think off gassing of the tires is a non-issue and they even point you to an article posted on their website to try and assuage any concerns. They even get a little aggressive about it, stating:

“The evolution of the Earthship building concept in addition to the evolution of the self-sufficient systems, i.e., power, water and sewage is an enormous undertaking. This is why we have given so little attention to the few who consider off-gassing a problem or even a reality. There has never been one instance of illness or even awareness of any off-gassing of tires in 40 years of research and development. Therefore, in our minds at Earthship Global, it is looming out there as a hypothetical issue coming from those who have never experienced the concept in person. In view of the above, and the serious issues surrounding current tire disposal globally, we think (but accept the fact) that those who are trying to make an issue out of this are irresponsible themselves.”
Well, besides that we got more than 30 calls and emails about this issue just this year, and we aren’t even an earthship firm… which suggests that more than a few people consider this an issue… we’ll just add a comment here from Brett Nibler from Oregon State University, who offered on EB’s website,

“The point is you must seriously address people's concerns, especially dissenters, if you are making a compelling argument for something. Saying "I don't really have time to discuss your concerns" for something so serious as a change to the building style and structure of homes carries very serious implications. Why do you think building codes have been established and construction styles have improved to withstand the elements over the years.”
We agree.

Below the snarky commentary quoted above, EB offers a typed transcription claiming to be a front page of a scientific report for proof that tires are not an issue. Outside of the report’s commentary being totally unprofessional, it should also be noted that this report is from 1995. If EB wants to accurately state their position, the “40 years of research and development” SHOULD read “the 20 year old research” if the only thing it can point to is that.

Which brings us to the most important aspect of their assertions… 1995, when that report was written, was, in fact, 20 years ago. There has been a great deal more research done on using scrap tires since then, and overwhelmingly, modern researchers recommend using tires in civil engineering, not architectural, applications. Further, they recommend that recycling rates be increased in the US as they have been in the EU. Let’s face reality here, head on: By using tires in construction, these materials are not being recycled. They are only being reused in such a way that those materials cannot go back to supply chain of production, which results in further extraction of virgin raw materials. So, in using waste tires for construction, we are actually INCREASING  demand for more mining, extraction of petroleum, and manufacturing, which requires energy (most often in the US, from coal) and transportation, which requires more petroleum, and time, and wears down our already crumbling infrastructure. That is NOT sustainable.

The bottom line is: Can you trust someone whose whole practice is based on selling this idea to admit that it is possible that people’s health is at risk?

Let’s go further here, and imagine a less than ideal scenario… your kiddo, or your beloved, ultimately gets sick from that “non-issue”. It can destroy you emotionally and financially. Is it worth ANY risk of that? In our digging into the data, we heard of several people who developed “allergies” living in earthships that they did not have before. A couple of those people moved out and have, after some time, returned to good health. Was it the earthship? Was it the tires? We cannot be sure. To be fair, we also have a friend with severe chemical sensitivities who lived in an earthship and found health again. We can only offer that in this, for us… if there is any question at all about the health, safety, and welfare of our clients, or their friends and family… there is no question what we must do to respond to it: we don’t take chances with people’s health.

The tires are, as far as we are concerned, and until a comprehensive blind study is conducted on earthships in every climate, will remain… an unacceptable risk. You can check out the research we’ve collected in the The Science: Tires and Offgassing section and make that choice for yourself.

What’s exciting is that EB also agrees that tires are not necessary. They even offer the option of using strawbale or adobe! Using earth, from right below your feet, as they’ve already proven… is easy to work with and IS sustainable. So why not use adobe instead? Cost to make one adobe brick: 1 length 2x8 plus dirt, straw, water, and sometimes… clay or sand. Add sunlight… and voila! But the best part: that frame can actually be used to make tens of thousands of adobe bricks. No intense pounding required.

One other note of technicality, despite what their website asserts about the tires being part of the wall system, it is not the tires that provide thermal mass. It’s the thick earth berm and rammed earth wall that gives thermal mass. No tires are actually required.

If you decide to go ahead with the tires: here is just a snippet of the chapter on dealing with tires from the book:

An average earthship requires about 900 tires for its back wall. Those tires are most likely not located on your building site. Or within 10 miles of your building site. Because most likely you’re going to be OUT THERE where it is still okay to do experimental architecture and live free of the encumbrances of “the man”. To get the tires to your site, you’ll need to make time to go select them out of a tire dump, which can take as much as 20 hours, and then you’ll need to transport them however many miles between the dump and your land. One option would be to get them all in one load on an 18-wheeler, which can carry 800 tires. But there are road access issues to address, rental and fuel costs and driver hire issues with that. So, let us look at a more practical option… you can get up to 50 tires piled and tied into the bed of a standard pickup truck, and get it done in 16 loads. And by the way, have you budgeted to sell your fuel efficient hybrid and get a pickup truck? Because now’s the time! How much mpg does the truck get? 24ish? So it’s what part of a tank of gas per load? Times 16 loads? How fast does that add up? According to the EPA report, “Scrap Tires: Handbook on Recycling Applications and Management for the U.S. and Mexico” from December 2010, the cost of transporting one tire in an average 25 mile haul (12.5 miles each way) was nearly $0.50. Multiply that by 900 tires and we have a fuel cost of $450 just for tires. And, that’s IF you have a truck! In EB’s own build videos, people are using compact cars to take tires to the site… at most, getting 5-6 tires per load! Holy moly, that is a lot of loads. And gas. A horse trailer would be a great option for this work.