Showing posts with label Building Materials. Show all posts
Showing posts with label Building Materials. Show all posts
  |  

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.
,   |  

Earthship Tire Off-gassing Research


Tire wall photo by Pratik Zaveri

We do not have a vested interest in saying that the off-gassing of the tires is a "non-issue." We do not believe that your health is a non-issue. Neither do the countries that have banned the use of tires in buildings. Because of laws prohibiting the use of tires, groups like Earthship Belgium are using earthbags instead of tires for their Earthships.

Just a few months ago, the tire off-gassing issue was raised again when The Washington Post did a story on a number of soccer goalies who have contracted cancer. Scientists and doctors began studying the unique subgroup, which led them to pose a link between the incidents of cancer and goalies who had played extensively on athletic fields paved with a form of AstroTurf that used crumb rubber from recycled tires in its makeup. While in its early stages now, this may ultimately prove to be fruitful research to the tire off-gassing issue. 

Here is what we DO know, from the scientific studies and best practices promoted by experts in the many fields which influence our assertion that the tires are dangerous, so you can decide what works for you!

The laundry list of volatile chemicals used in tires is alarming: 
·         Benzene inhalation causes cancer
·         Toluene inhalation causes cognitive disfunction
·         Arsenic inhalation causes organ failure
·         Acetone inhalation causes irritation of the throat and lung

plus heavy metals that include
·         Nickel inhalation causes sinusitis and cancer
·         Copper inhalation causes nausea and suppressed liver function
·         Cadmium  inhalation causes kidney disease and an increased frequency of kidney stone formation

Organic compounds in tires break down more quickly than the vulcanized rubber. Criteria which determine breakdown rate include: heating, friction (from movement), water trapping and freezing, and evaporation of plasticizers.

But here is where it gets REALLY interesting. Here are scientific studies done for several different materials, all of which are constructed of recycled tires.


“These (tire) piles pose a public health concern. They are breeding grounds and havens for mosquitoes and other vectors, resulting in the spread of dengue fever, yellow fever, encephalitis, West Nile virus, and malaria. Improperly managed in stockpiles, in illegal dumps, and scattered along road sides, scrap tires are a significant border environmental problem as a result of the leaching process, fires hazards, and water contamination. Once ignited, tire fires are difficult to extinguish. When water is applied to fight the fire, serious air, ground water, and surface water contamination may result. Toxic emissions from tire fires, such as sulfuric acid and gaseous nitric acid, can irritate the skin, eyes, and mucus membranes, and can affect the central nervous system, cause depression, have negative respiratory effects and, in extreme cases, cause mutations and cancer.”

This 2008, but constantly updated ,report from Artificial Turf: Exposures to Ground Up Rubber Tires - Athletic Fields, Playgrounds, Garden Mulch by the firm Environment and Human Health, Inc. for the Canada version of the EPA

"The metals zinc, cadmium, and lead were also identified as contaminants from tire rubber released into ground water. With the exception of zinc, there are insufficient data to assess the health or environmental risks of any of these metals. It appears clear that the zinc levels are high enough to be phytotoxic if they enter the ground water or soil. It is doubtful that there is any human toxicity from zinc at the levels reported, but such a conclusion would have to be tested by more careful study."

"The particulate exposures due to tire dust and chemicals contained in the dust that can be released in the lungs are especially troublesome. Nearly every test adequate to assess the risk that was reported found one or two dozen compounds released from particulates. There are processes in the body that can release the chemicals contained in the rubber particles. Moreover, potent carcinogens are found in the tire dust. Only the assumption of limited exposure could support the conclusions of low cancer risk."

"In summary, the toxic actions of concern from the materials… include: Severe irritation of the respiratory system; Severe irritation of the eyes, skin and mucous membranes; Systemic effects on the liver and kidneys; Neurotoxic responses; Allergic reactions; Cancers; Developmental effects"

2012 Cal Recycles Report on Tire Breakdown, which states:

" Natural rubber alone poses a dangerous fire hazard and when heated to decomposition emits toxic fumes of SOx. Base materials used in polymer rubber production, such as butadiene and styrene, are suspected human carcinogens, and many of the polymer additives can cause systemic toxic effects."

"The tire filler, carbon black, is mildly toxic by ingestion, inhalation and skin contact."

"Isoprene is a mild toxic by the pathway of inhalation. It also reacts with air and ozone to form dangerous peroxides. Butadiene is a confirmed carcinogen and teratogen in animals and a suspected human carcinogen. Inhalation of high concentrations of butadiene can cause unconsciousness and death. Human systemic effects of butadiene by inhalation include coughing and hallucinations. Styrene is a suspected carcinogen. It has been found to be poisonous by ingestion, inhalation, and intravenous routes."

"Zinc oxide is added to tire rubber at relatively high concentrations. Zinc oxide is moderately toxic to humans by ingestion. Some human systemic effects associated with the inhalation of zinc oxide are chills, fever, tightness of the chest, and coughing."

The 2013 report: Draft Screening Assessment for Carbon Black produced by Environment Canada, which states:

"Increased incidences of lung tumors were observed in female rats exposed by inhalation to the only or lowest concentration (of carbon black) tested..."

This 2008 report from Liberty Tire, which states, specifically about off gassing:

"The 2007 EEDEMS report mentioned above raised concerns about health effects on the crews installing crumb rubber athletic fields in poorly ventilated indoor areas and recommends a minimum air renewal rate of 2 vol.h-1. A 2006 study conducted in Norway drew a similar conclusion... These recent findings are consistent with those of a 1999 Taiwanese study that identified temperature and age of the recycled rubber material as the primary factors in VOC emission rates."

And then you read statements from industry professionals dealing with tire decompositions in their everyday lives, who say things like...

"While the levels of chemicals off-gassing from indoor play spaces was considered below the threshold where the chemicals are harmful, it is worth noting that indoor spaces showed up to ten times as much volatile chemicals in the air. If you want to err on the side of caution, you may want to consider refraining from using recycled rubber mats indoors, where there is a minuscule but present danger that could deem recycled rubber unhealthy." in "Are Recycled Rubber Mats Unhealthy?" by Lara Stewart at BrightHub based on the research noted  in the first report we suggested reviewing.

"Minor off-gassing is an issue with rubber flooring. The gasses have an odor but will not release hazardous chemicals. In some cases, products with recycled content are included with caveats regarding where they should be used. Rubber flooring made from recycled automobile tires is a good example--the caveat is that these products should not be used in most fully enclosed indoor spaces due to offgassing concerns." from "Building Materials: What Makes a Product Environment Friendly?"at Earthwise.com

"Do not use rubber flooring, such as that made from recycled tires, in enclosed areas because off gassing can continue for years." "Healthy Indoor Environments"  at The Sustainability Project.

But then, to be fair, we cannot ignore this archived, undated, report from Humbolt State University, which addresses the risks in earthships directly.

“Reusing our worn out tires is of course better than throwing them into a landfill, but many of the current reuse applications found in our society come with significant environmental impacts.  

One appropriate use for old tires is in Earthship homes.  A question we frequently receive … is if the tires used in these projects pose health risks through offgassing or chemical leaching.  “it depends”. 

The specific constituents contained in a given tire (e.g. arsenic, aluminum, cadmium, chromium, manganese, mercury, lead, sulfur, and zinc) are dependent on the tire’s type, age, and manufacturer.  The location in which the used tires are placed is a critical factor that determines how much of each mineral constituent is leached.  Tires decompose when exposed to high temperatures, sunlight, or oxidizing agents.  None of these elements are present when a tire is packed with soil and surrounded by a stucco barrier inside an Earthship.  That being said, the tires used in Earthship walls are of minimal risk to inhabitants because they have little potential to decompose.

…used tires most likely do not pose a health risk if they are rammed with earth and sequestered in a location away from exposure to sun or moisture… EPA researchers have acknowledged that the current literature we have pertaining to the health risks that used tires pose is incomplete, and that further study should be conducted before used tires are used in applications where humans are exposed”

Once you have read some of these reports, or just the excerpts we have included here... ask yourself, is it worth the chance you take? If your answer to this is yes, Part 2 of the book has suggestions for making them work. If the answer is no, then Part 2 will also offer viable alternatives!
  |  

Earthship Glass Block and Bottle Walls

Glass Wall
We LOVE the look of the colored glass walls used in earthships. But did you know that it’s more difficult now to find the bottles you need in multiple colors? Recycling has made things better, unless you happen to be looking for cool materials for your glass bottle wall. So many earthship builders spend months and sometimes even years scavenging for and collecting the “right” bottles, or, they *whispering*...they BUY the bottles in the colors they want them in.

While beautiful, the glass bottle walls are poor insulators. So, many people now only use them on the south or west exterior walls... if they are leeward (the direction the wind normally GOES), and on the interiors of the home. Don't use bottle walls on the north unless you live in Mexico or parts south where winter is pretty much "summer-lite." Basically, you only want bottle walls where the need for insulation is minimized.

Maintenance-wise, the glass bottles of yore pose another concern: grossness. The open ones that were originally used in earthships collect bugs and dust, they are ugly on the “cork” side, and they break easily. Cleaning them can easily be a full time job.
Many people, including EB, now take the bottoms of two bottles and to tape them together and make what is referred to as a “bottle brick”. You will need about 2000 bottles, a means of cutting them, and ducttape to make the standard 1000 bottle bricks. You’ll want to remove the labels by soaking the bottle in water with dishsoap and then using a putty knife to remove what remains. Using gloves, to keep from getting cut, etch the bottle 4” above the base using a sharp glass blade cutter and dip the etched bottle into hot but not boiling water for 10-12 seconds, then dip it in a ice cold bath for a few seconds, and the hot again... until this cuts the glass through. Alternately, a high quality tile saw works well to do this quickly. Wash and dry the bottle ends completely. Using a clear glass end and a colored glass end for the most light transmission, tape the bottles together with duct tape, painting tape, or two layers of packing tape. Here's a GREAT Step-by-Step Guide to Making Bottle Bricks from Manitoba Earthship Project!
Another trick for not using glass bricks but getting the same effect which many builders already know and are using: use pretty colored and shaped glass blocks. Which kindof moots the point of the walls “recycling benefit”. But it works. For the long-term. Maintenance is minimized, thermal performance is maximized, and privacy is maximized. Plus you can get EXACTLY the look you want.
Earthships (19)
Glass blocks and bottle walls should not be used as loadbearing walls, and they should be laid not in concrete but in Type S mortar or cob of not more than 3/8” in thickness. For stability, especially if used on the exterior, these walls should not extend more than 15 feet in any direction and should be limited to an area less than 140 square feet overall. Curved wall sections are possible, but require an expansion joint at each change of direction. The radius of the curve should be limited to no less than 4 feet. 
Expansion joints, an expansion strip between the glass and the regular wall and sealed with a sealant either side, should be installed at the heads and sill of exterior glass block and bottle walls, especially, to allow for movement and settling. Use recycled content expansion joint filler for these locations.