Hydraulically compressed Greenstar Blox, ready for construction, at the Mason Greenstar facility in Mason.
Don Dille

Imagine There’s No Concrete: Building a Papercrete Revolution in Mason


A version of this story ran in the June 2014 issue.

Above: Hydraulically compressed Greenstar Blox, ready for construction, at the Mason Greenstar facility in Mason.


Kent Rabon, stocky and square jawed, pushed open the heavy wooden doors and stepped out of the tiny white chapel into the West Texas sun. He shielded his eyes and looked out across the vast Chihuahuan Desert rimmed by red mountains. Rabon, 61, had spent the past 35 years as a builder, erecting custom homes from stacks of pine two-by-fours and plywood. He’d come here, to Marathon, in the spring of 2003, on a sojourn in search of meaning. Inside the chapel, he’d sought a moment of personal reflection.

Standing outside the chapel, Rabon noticed a man across the street stacking bricks, building a wall with a material unlike Rabon had ever seen. The bricks were homemade, 80 percent lighter than traditional concrete blocks, highly insulating, and they rivaled wood and concrete in strength. The walls formed archways and transitioned smoothly into domed ceilings. Rabon walked over and said hello.

The man, Clyde T. Curry, weathered by the desert, was a builder as well. He called the brick material papercrete, and he showed Rabon how he made it, mixing shredded newspapers, lottery tickets and old telephone books with Portland cement and sand. He poured the resulting gray sludge into square forms and let the bricks dry in the desert air. Then he piled the bricks into walls using wet papercrete as mortar.

Rabon learned that Curry and his wife, Kate, were erecting a bed and breakfast, Eve’s Garden, which now has seven suites surrounding a babbling koi pond.

The papercrete structures intrigued Rabon, but he didn’t immediately see any reason to change his methods. He knew traditional materials, and he knew how to make money using them. In Rabon’s view, wood framing, fiberglass insulation and concrete were normal. Even so, he spent an hour talking with Curry.

As Rabon said goodbye, Curry handed him a homemade papercrete brick to keep as a souvenir. He told Rabon he’d been hoping to meet someone who owned a concrete plant. With a commercial concrete mixer, a person could mass-produce papercrete bricks. And if a person could mass-produce papercrete bricks, it just might change the way people build their homes and offices.

Rabon had someone in mind.

The covered papercrete courtyard at Eve’s Garden Bed & Breakfast in Marathon.
The covered papercrete courtyard at Eve’s Garden Bed & Breakfast in Marathon.  Ian Dille

The origin story of papercrete is archived on homemade websites filled with dancing icons, excitement and wonder, where anything seems possible, even houses made of paper. According to the Internet’s cache of papercrete history, the first patent for a papercrete-like material was established in 1928, but no commercial industry ever emerged, the story goes, because there was no money in papercrete. Making it was easy, and anyone could do it.

Also, paper was expensive in the early 1900s.

Then, during the late 1980s, various individuals in Colorado, New Mexico and Arizona independently rediscovered the process and began experimenting with papercrete. More patents were filed, but they were never enforced. Assorted papercreters sometimes gathered for seminars on the material and shared ideas in the Yahoo group “Papercrete Info exchange.”

Though they lived all across the U.S., in a sense the papercreters were unified by location. They tended to live on the fringes of the grid, or off it entirely. Most resided in jurisdictions with lax building codes, or no building codes at all, where they could build without restriction.

Papercrete is not commonly encountered by city and county building inspectors—the cops of residential and commercial construction. Though building inspectors are often considered the bane of DIY builders, they perform an important public service: enforcing standards that minimize the risk of collapsing ceilings and electrical fires, for instance. The bible of nearly every building inspector in the United States is produced by the nonprofit International Code Council (ICC). Cities across the U.S. have adopted the ICC codebook into their local building ordinances, making it, essentially, construction’s law of the land.

That law accounts primarily for conventional building materials such as steel and wood and poured concrete. A host of other structural building materials—including adobe, straw bale and papercrete—fall under code section 104.11, “alternative materials.” Building inspectors approve such alternative materials, or don’t, on a case-by-case basis. If you want to build a papercrete house in Dallas, you’ll need to provide the local building inspector with test data documenting the material’s load-bearing capacity and fire-resistance rating. After reviewing the tests, and perhaps requiring more of them, the building inspector will decide whether you can build your home out of papercrete or not.

In part due to this bureaucratic onus, most builders stick with traditional materials. Today, most so-called green construction focuses on energy efficiency. The materials from which many green homes are built still represent unsustainable depletion of natural resources and additions to atmospheric greenhouse gasses. Cement, for example, accounts for up to 8 percent of the globe’s carbon dioxide emissions, and is the second-most consumed substance on Earth (after water). The building industry considers wood a sustainable product, since we can grow more, but not all lumber is harvested sustainably. For example, in 2012 IKEA used nearly 1 percent of the world’s lumber supply in its products, and less than a quarter of that wood came from certified sustainable wood suppliers.

In 2012, the ICC published a green-building code. In municipalities that have adopted the green code, certain construction efficiencies have become mandatory. But the green code, as well as rising consumer interest in green building, has had little impact on global quantities of concrete poured or forest harvested. In part because of the difficulties that alternative materials pose to the code process, no sustainable structural building material—like papercrete—has ever gained a widespread commercial foothold.


A papercrete staircase at Eve’s Garden.
A papercrete staircase at Eve’s Garden.  Ian Dille

When Kent Rabon returned from Marathon to his home in Mason, a small town about 120 miles northwest of Austin, he showed the papercrete brick Curry had given him to his son, Zach. Unlike his dad, Zach—thickly built and blond-haired with a sleeve of tattoos on his arm—eschewed building-industry norms. He’d long envisioned a greener method of building. In 1999, he graduated from Texas Tech University with a degree in environmental conservation of natural resources. Unsure how to apply his new knowledge, Zach moved back to Mason and joined his dad’s construction business. In 2002 he bought the local Ready Mix concrete plant.

Zach was astonished by the papercrete brick’s light weight and strength. With the knowledge of cement additives he’d gained from the Ready Mix business, he felt confident he could produce an even stronger version. Zach traveled to Marathon and spent three weeks with Curry (whom he calls “the guru”), learning all he could about papercrete. Back in Mason, Zach partnered with a college buddy, Josh Hargrove, who’d also taken an interest in papercrete. They began throwing homemade bricks off of buildings and shooting bullets into them. They tried, unsuccessfully, to set the bricks on fire, and tossed them into ponds to see how they held up in water.

In 2005 Zach decided to set aside his successful concrete business and focus solely on the goal of commercializing papercrete. When he told his wife, she left him. Heartbroken but undeterred, Zach founded a company with Josh (who remains as chief technology officer), named it Mason Greenstar, and started hand-manufacturing thousands of 10-inch by 14-inch by 4-inch papercrete bricks. Zach called them Greenstar Blox, and when he indulged his wildest ambitions, he imagined them changing the construction industry forever.

La Loma del Chivo, a papercrete hostel in Marathon.
La Loma del Chivo, a papercrete hostel in Marathon.  Ian Dille

In 2008, as Zach Rabon’s somewhat crude-looking Greenstar Blox baked in the sun in a Mason field, a pair of Silicon Valley entrepreneurs named Randy Schmitz and Trevor Stout were preparing to mass-market a product called Integrity Block. At the time, Integrity Block was touted on environmental blogs and at green-building trade shows as a game-changer for the construction world. In a recent telephone interview, Schmitz told me that Integrity Block was “the most sustainable building block ever made.” Today it’s little more than a cautionary tale for companies like Mason Greenstar.

Integrity Blocks, like papercrete, relied on recycled materials for the bulk of their content. The alternative building process that Integrity Block modified for commercial use is known as rammed earth. In rammed-earth construction, builders take local soil, filter it for consistency, and compact it into dense bricks. Aggregate quarries churn up refuse soil by the ton, and Integrity Block aimed to mix these unused soils with cement and press them into blocks for individual sale.

Integrity Block patterned the design of its product after concrete masonry units, or CMUs, those large, hollow, concrete blocks that typically compose the walls of big-box stores like Best Buy and Target. Integrity Block claimed the product met existing standards for concrete masonry units. Thus, Schmitz and Stout reasoned, it should be cleared by code officials for use in most municipalities.

In 2008, Stout told the now-defunct California Real Estate Journal that Integrity Blocks were slated for use in an 800,000-square-foot shopping center, and the company sought a deal to sell Integrity Blocks in Masdar City—an experimental zero net energy consumption metropolis near Abu Dhabi, in Dubai. But by 2010, Integrity Block had ceased operations. The company sold off the hydraulic equipment used to press its earthen blocks and shuttered its sleek website.

Schmitz blamed his company’s demise on the “dirty tricks of the entrenched building industry”—an industry Schmitz said was threatened by Integrity Blocks. Schmitz also said the building industry wouldn’t be happy to see his story in print. When I pressed him further, he said he was slammed with work and couldn’t talk.

I later came across one of the dirty tricks Schmitz had referenced. In the September 2008 newsletter of the Concrete Masonry Association of California and Nevada—an organization representing companies that produce and build with traditional CMUs—I found a two-page opinion piece titled “Product Warning—Some ‘Green’ Building Materials May Not Be Safe,” in which the association’s executive director, Kurtis K. Siggard, repeatedly uses the word “soil” to describe Integrity Blocks’ primary component. The pejorative inference is unmistakable.

“The design and construction industry are being duped by promoters of compressed soil materials,” Siggard wrote, insisting that the structural testing standards that Integrity Block claimed to meet were written specifically “for Loadbearing Concrete Masonry Units, not…for Compressed Soil Products.” In closing his argument, Siggard played up the tree-hugging stigma of green building and turned the words of Integrity Block promoters against them, writing that the product had been developed by “people who would be happy to be called ‘hippies.’” Siggard suggested that builders stick with a known entity—concrete—rather than risk trying something new.

In clouding Integrity Block with skepticism, Siggard was highlighting an inherent bias in the building industry against new and innovative materials. An Integrity Block is not a CMU. Builders could not simply begin using Integrity Blocks in place of CMUs under existing building codes. Testing standards and building codes are written specifically for conventional materials, like concrete, and even if Integrity Blocks met the same rigorous standards, as the company claimed to have done, the product would still be subject to the case-by-case code approval required of alternative materials.

To garner code compliance, an alternative material must undergo an ICC evaluation process. A company seeking to bring an alternative material to market must develop specific tests for its product and pay a recognized third-party laboratory to administer them. Based on the results of the tests, the ICC will issue an evaluation report that code officials can refer to when reviewing building plans. If the product proves successful, the evaluation report will be written into the ICC code itself. The ICC evaluation can cost as much as $250,000 and take more than a decade to complete. The process is beyond the wherewithal of most start-ups and leaves the bulk of innovation in the hands of established companies with little incentive to introduce new products to a market in which established materials hold an effective monopoly.

Due to the bureaucracy, cost and time involved in the ICC evaluation process, a competing organization, Underwriters Laboratories (UL), has started offering similar product-evaluation services to building-industry entrepreneurs. Though UL standards aren’t universally recognized by city code officials, who have the final say about how a home is built, many people in the building industry believe that competition in the certification world can only help foster innovation. One such person is the former CEO of the ICC, Bob Heinrich, who once oversaw that company’s evaluation services.

When I spoke with Heinrich on the phone, he seemed hesitant at first to criticize the ICC, but he ultimately spoke candidly. “The company I used to be involved with has, to some degree, lost sight of who their true constituency is, and it shows. It shows in the evaluative services side, fairly predominantly, and it has left a hole in the industry,” Heinrich told me. “The focus is off the consumer and more on ‘what can the industry give us,’ because over the last few years the economy has been hard on the ICC. Every time I turn around, I have someone in the building industry saying, ‘All the ICC wants is another dime, another dollar out of me. It’s not that they care what will work for me as their client. It’s how much money I will make them.’ The ICC is a nonprofit organization that’s supposed to be lessening the burdens of government, and I think that focus may have been lost a little bit.”

Reflecting on how his former colleagues might perceive his comments, Heinrich said, “That one is really going to get me in trouble.”


Undeterred by Integrity Block’s fate, Mason Greenstar pressed forward. In 2009, Zach Rabon built a wall of Greenstar Blox in a FEMA-accredited lab in Lubbock for impact testing. There, engineers simulated severe hurricane conditions by firing 9-pound two-by-fours into the wall at more than 100 mph. None of the boards penetrated the wall. Back in Mason, Zach built his own 3,200-square-foot home out of Greenstar Blox, leaving the bricks unpainted to see if they’d deteriorate in the weather. Kent, who first scoffed at his son’s obsession with papercrete, eventually became a convert. He built his own papercrete home and became Mason Greenstar’s chief operations officer, overseeing job sites. Later, Zach hired Clyde Curry, his Marathon papercrete guru, as the company’s chief innovation officer.

In 2011, Zach received a patent for his proprietary papercrete blend (after his lawyer warded off a patent challenge from the purveyors of HardiePlank, a common wall siding composed of concrete and fiber). That same year, with assistance from the Angelo State University Small Business Development Center, Mason Greenstar received a $50,000 Eureka Grant from the State Energy Conservation Office. Then the Lubbock building inspector approved Greenstar Blox for use in a 4,000-square-foot million-dollar residence—the second Greenstar Blox-built urban home approved under ICC’s alternative materials code.

In 2012, Texas Tech’s department of civil and environmental engineering performed further tests on Greenstar Blox. A team of professors and graduate students crushed the bricks to measure the pressure they could withstand and subjected them to an arduous freeze-thaw cycle. After determining that the Blox are of suitable strength for residential structures, the university purchased a small percentage of equity in Mason Greenstar and opened the school’s scientific resources to the company.

In 2013, Mason Greenstar purchased a custom-designed hydraulic press and developed a slate of new products, including a papercrete brick modeled on a traditional CMU. The new product is sharp-edged and smooth-looking. Mason Greenstar claims its automated press can churn out two of these blocks every 40 seconds. Following Lubbock’s lead, the City of Fredericksburg has green-lighted Greenstar Blox for residential construction this year.

At the end of January, Zach Rabon loaded up his Blox and headed to Las Vegas for World of Concrete, the industry’s largest trade show, held in a 500,000-square-foot exhibit hall, where Mason Greenstar would compete against established companies for the convention’s Most Innovative Product award.


A few weeks after Zach returned from Vegas, I visited him at his office in Mason. The office is built of papercrete. A pet pygmy alligator greets visitors. (A 4-foot Nile crocodile used to reside at the Mason Greenstar office, but it escaped during a flood and was shot by a local rancher after it turned up in a stock pond.) A section of the office wall—Zach calls it a “truth window”—is blackened and scarred where he has allowed prospective clients and investors to whack the blocks with a sledgehammer and try to burn them with a blowtorch. A wrinkled piece of notebook paper, on which Curry first scribbled papercrete’s ingredients for Zach, hangs in a frame. The brick that Curry gave to Kent in Marathon sits on a mantle above the office’s front door.

“We were like rock stars,” Zach said of his trip to Vegas. He says the company’s booth attracted hordes of attendees who snapped photos with the Greenstar Blox and asked Zach to autograph their World of Concrete backpacks. Shortly after returning to Mason, Zach learned that Mason Greenstar had won the award for Most Innovative Product in the category of Masonry Materials and Equipment.

Zach said that major paper companies are now vying for Mason Greenstar’s attention—a development that could make papercrete even cheaper and greener. Paper companies have a problem: They generate tons of wet paper fibers that are too short to turn into notebooks or tissues, and so end up in landfills, or are dried and burned. Eager to save millions in disposal costs, such companies might prefer to give their paper waste to Mason Greenstar.

Potential competitors have also come calling, seeking to purchase or partner with Mason Greenstar. Zach has already met with one of the country’s best-known brick manufacturers, but, he says, they face a dilemma: If the company starts distributing papercrete blocks, how will it continue to sell clay bricks?

Zach is optimistic that his products will one day be enshrined in standard construction codes. “We’ll write the code for papercrete and force everyone else to meet our standards,” he said. His dad, Kent, is less diplomatic: “We need that ICC approval, even though it’s a bunch of bullshit,” he said.

If Mason Greenstar gains ICC code approval and succeeds in mass-producing a commercial papercrete block, it may yet change the way we build homes, with less reliance on wood framing and more on recycled products. Yet papercrete remains just a step toward the ideal of a construction method that doesn’t pollute the planet. Cement still makes up 20 percent of every Greenstar block, and a pound of carbon dioxide enters the atmosphere for every pound of cement produced. Greenstar Blox are like a car with incredible gas mileage, not a car that uses no gas at all.

And Mason Greenstar may soon encounter a new competitor in the sustainable building materials business. Integrity Block has reemerged as an entirely new company called Watershed Materials. The new CEO, David Easton, told me that, this time, “We’ve been careful not to make any enemies in the building industry.” Watershed Materials qualified for grant funding from the National Science Foundation and aims to form national partnerships with quarry companies. Inside of two years, Easton told me, Watershed Materials plans to produce a block containing no cement at all.

As I leave the Mason Greenstar office, a bus full of students from the town’s elementary school arrives. Zach has remarried, and his new wife is a teacher at the school. The students have been collecting recycled paper and delivering it to Mason Greenstar. Zach and his employees show the kids how they shred the paper, mix it with cement and sand, and turn it into bricks. Mason Greenstar hopes to provide the building blocks of a new wing being planned for the elementary school. One day, the students may attend classes inside that building. To them, by then, a classroom made of recycled paper may seem completely normal.