I love traditional adobe buildings. They are beautiful and handcrafted and made of clay earth, which I foolishly assumed meant they were safe from toxic chemicals. It turns out the world of adobe bricks is more complicated than that. First, let me explain the difference between stabilized, semi-stabilized and unstabilized adobe bricks:
Stabilizing adobe means the clay rich soil is mixed with an asphalt emulsion to make the adobe brick more water resistant.
“Adobe may be stabilized with asphalt emulsions. Asphalt emulsion is made by combining asphalt, a byproduct of crude oil distillation, and water and proprietary surfactants.”
Green Building Materials: A Guide to Product Selection and Specification, Ross Spiegel, Dru Meadows
In some cases, a small amount of kerosene is added to the asphalt emulsion to make it thinner and easier to mix into the clay rich dirt. Obviously asphalt and kerosene are not suitable for a nontoxic house, so we asked traditional adobe builders if we could build with unstabilized, emulsion-free adobe bricks. “Yes,” they said, “you just have to put a nice thick coat of adobe plaster over the bricks to protect them. This coat will wear off, though, so you will have to re-apply it once a year.” That sounded like kind of a hassle and an extra yearly expense but we were still committed to the idea of adobe so we hired an adobe builder. The adobe builder said, “The state of New Mexico requires that the first 3 courses be made of stabilized adobe bricks because they protect the building from water damage.” OK, we said, we’re going to explain to the building code people about my health issues and ask that this requirement be waived. We drafted a letter, submitted it, and they said “we accept your request and waive this requirement for you.” (It wasn’t quite this simple. We had to wait for a special board to meet, our building project ground to a halt in the meantime, and the bank was getting increasingly impatient with our slow moving project.)
With our approval in hand, we were once again moving forward and building was scheduled to begin. Building days were particularly challenging for me since diesel trucks carrying building materials would fill the valley our land is in with fumes and workers wearing strong colognes (despite being asked not to) would arrive in large numbers. I mention this because I was nowhere near the building site on the day the adobe builder began work. This will become relevant later in the story.
Where was I? Throughout the building of our house, I would take a small folding chair, a bottle of water and my Kindle and hike off into the desert to stay safe. They were long days, beginning at 8 am and lasting until 5 pm, with a happy break in the middle when my husband would show up with lunch.
A typical summer day in the high desert looks like this: comfortable temperatures in the morning become searingly hot by noon, high 90’s to over 100 degrees Fahrenheit are not uncommon, followed by sudden high winds and a half hour of torrential rain with thunder and lightning and possibly hail in the late afternoon. After the thunderstorm, the sun comes out and snakes become more active, looking to warm up after the rain—so there’s that to look forward to as well.
Also I never succeeded in finding a sunscreen that didn’t give me a rash and brain fog (even from the unscented ones) and a headache, so I had to hold an umbrella in one hand while holding my Kindle in the other. On the upside, the umbrella-holding arm had excellent forearm strength by the end of the project.
After a long day of adobe building, the builders had laid enough adobe bricks to create all the walls, interior and exterior, up to my knees. My husband and I had dinner at our campsite, and then I went over to see the work. I immediately got dizzy and headachey as I approached. At first I thought someone spilled fuel of some kind or perhaps someone’s truck leaked automotive fluid, but then I realized the smell got worse the closer I got to the building. I kneeled down and sniffed the adobe wall. It smelled of tar. “They used stabilized adobes by mistake!” I thought, horrified. But the next day, the adobe builder insisted he had used only unstabilized adobes. Later he admitted he was short unstabilized adobes and had used some number (he was vague about this) of stabilized adobe bricks in our walls. After much arguing back and forth, he finally came back with his crew and removed all the adobe brick walls he had laid as well as the pile of stabilized and unstabilized adobe bricks fuming away in the hot sun.
We were shaken but undeterred. We needed another adobe builder, obviously, but we learned something else during this debacle. His unstabilized adobe bricks didn’t smell as strongly of asphalt and kerosene, but they still smelled. Why? I called many adobe brick makers and they all said the same thing, “We make the unstabilized adobe bricks in the same equipment we make the stabilized ones in. No we do not clean the equipment first.”
Still we were undeterred. We just have to find someone who makes only unstabilized adobe bricks, how hard could that be? I called all over the state, looking for these bricks. Another problem cropped up. Many people paint the inside of their adobe brick forms with a “release agent.” Enamel paint, used motor oil, and grease were some of the answers I heard after I learned to ask if they used anything in their forms to make the adobe bricks easier to remove. Finally, we gave up on traditional adobes.
But wait! Someone asked us if we had looked into compressed earth blocks. Compressed earth blocks are made by squishing clay rich soil and a small amount of Portland cement together at high pressure in a compressed earth block machine. These machines can produce adobe bricks quickly and without the danger of cross-contamination by asphalt emulsions. Great, we said. Let’s do that. We found a compressed earth block builder in Colorado and arranged to resume our building project. (This is the point where the bank started threatening to cancel our building loan.)
On a very windy day, the diesel powered compressed earth block machine was dropped off on our land. By dusk, the winds died down and then it became dead calm, windless. Immediately, diesel fumes filled the valley, trapped by the mesa just south of us and a mountain to the north. First I got severe brain fog, then a headache, then this creepy central nervous system reaction I get where I become uncoordinated, shaky and tremory. Panicked, my husband hiked off to the phone jack post in the driveway (there was no cell signal on our land at the time and of course no house) and called the builder. One of his workers arrived the next morning to tow the compressed earth block machine back to Colorado. It was a long night and it took many days to recuperate from this episode.
The compressed earth block maker suggested he could make the blocks somewhere else and transport them to our building site. I had already successfully tested the soil, but considering the severity of the diesel fumes coming off the machine, I decided it would be prudent to spend some time with a few blocks made by the machine. Not surprisingly, the blocks had absorbed diesel fumes during production and the test did not go well.
Next we researched compressed earth block machines to determine if a non-diesel machine existed that could be used instead. We discovered a small, air compressor powered machine that only produces two 10” x 14” sized blocks at a time. We were told we would need 3,200 blocks to build our 1,500 square foot house. Two people could only make about 40 to 50 blocks a day on this machine which would mean it would take two and a half to 3 months to make the blocks we would need, assuming they were being made 7 days a week and bad weather never happened. Meanwhile, over 3,000 blocks would need to be kept covered while drying to protect them from the rain (how would we do that though, since I react to large sheets of plastic and those blue tarps everyone uses). We decided it did not make sense to buy this machine.
Then we panicked because we didn’t know what else to do and bought the machine. It looks crazy from this perspective (and it was). But we had come this far, we had in our possession approved building plans for an adobe house I designed and an architect had converted to blueprints that were filed with the New Mexico building permits department. This process was time consuming and costly and we would have to do it all over again if we changed building materials. And we had been camping outside on our land during this long ordeal for over a year. And we didn’t know what else to do. (I know I said that already.)
It took six weeks for our little compressed earth block maker to arrive. When it did, my husband uncrated it and immediately came to find me and report that it smelled pungently of paint. Finally, only at this point, did we abandon our plans to build an adobe house. We decided to go back to our original plan to build a pumice-crete house before fears of the possibility of high radon levels scared us off pumice-crete.
How did the bank feel about all this? They told us our building loan would have to be re-approved. At this point, we had a well, electrical power brought to the land, a septic system and a slab, all paid for with a chunk of our building loan. If we were not re-approved, we would have had to pay back the portion of the loan we had spent. All at once. This would not have been possible.
It was a long stressful summer, but we were finally re-approved in September 2009. We moved quickly this time, calling the pumice-crete contractor and all the subcontractors we had lined up during the re-approval process. By March of 2010, the house was completed and the state of New Mexico issued us a certificate of occupancy. It was finally over. It took me a year and a month before I could move in, so that stress wasn’t over, but at least we could sell the house and try again if—worst-case scenario—it was never safe for me.
I share this story to warn you of some of the issues you many encounter with adobe. If you have a source of unstabilized adobe bricks that are made in safe forms, have at it! And send pictures. I still love the idea of building from earth and have seen many beautiful old adobe buildings here in New Mexico.
One day during that stressful summer, my husband and I drove to Chaco Canyon where buildings made of stone cemented together with clay earth mortar still stand, even though they were abandoned around 1,200 AD. They are stunningly beautiful and as we ran our hands over the meticulously crafted stonewalls we both said, “I wish we could build a house like this!” (if only)