Desert Exposure Paper Adobe June 2006

Paper Work

An Earth Day project leads an eco-minded inventor to develop an earth-friendly building material—"Padobe"—out of paper.

One fine Earth Day morning 16 years ago, Eric Patterson engaged his young daughter in a little eco-project. Patterson, owner of the Unicorn Press print shop in Silver City, had decided there was just too darn much paper going to landfills.

"What else can we do with this stuff, other than throw it away?" he recalls asking out loud. The man who wears a "Stop Global Warming" wristband, and whose business produces huge amounts of waste paper, was motivated to find a "green" solution. Familiar with the concept of "papercrete"—building blocks formed of waste paper and cement back in the 1950s—Patterson decided to experiment.

Eric Patterson mixes up a batch of "Padobe."

After soaking a bunch of his shop's waste paper, he ground it up in a blender, creating a soggy, soft pulp. He then added the stuff to some cement and formed a simple block.

"It didn't harden up by the next morning, so I figured I'd failed and forgot about it. 'Nice idea, but I guess it doesn't work,' I told myself. Then, about two weeks later, I came upon (the brick) just lying in my yard where I'd left it and picked it up," he recalls. "Not only was it hard as a rock, but it was amazingly light, even lighter than when I'd made it, because it had dried out."

Since then, Patterson has worked on refining the process on a small scale in his own backyard laboratory, learning from his mistakes and tweaking his recipe.

There are a number of ways to make construction building blocks from paper. The generic term for the method is "papercrete." The name seems to imply a mix of paper and concrete, but actually cement is what's most often used. (Perhaps it would be more accurate to call the product "paperment.") Different formulations use different binders—fibrous concrete, sand and earth among them—and the blocks can contain 50-80 percent waste paper.

Patterson calls his style of block "Padobe" and he holds the patent on the formulation. With his project growing from an Earth Day experiment to actual application, he's graduated from a kitchen blender to a custom homemade industrial-sized contraption that churns out gallons of the requisite paper pulp in minutes, pumped out into a custom-made trough for draining.

"Let me show you how it works," he says, jumping up onto a wooden platform holding a large black barrel. The motorized gadget visible on the bottom of the vessel indicates this is no ordinary rain barrel.

Reaching into one of several big trashcans holding scads of paper strips—junk mail, trashed books, trim ends from the print shop—soaking in water, Patterson hauls out handfuls. He fills a big plastic cooler, a measuring cup of sorts, twice over. He dumps the soggy paper into the barrel and then fills it two-thirds full with water.

"It takes a lot of water," he says, "but my system recycles about 80 percent of it."

Patterson flicks a switch and the contraption churns to life. After about five minutes of the machine's grinding, Patterson reaches into the top—don't worry, the industrial-sized blender blades are on the bottom, he says—and pulls out a double handful of the pulverized stuff. Thanks to a large proportion of yellow oak-tag-type wastepaper, this batch has a cheerful yellow cast.

He shuts off the blender and jumps down from his wooden perch.

"Stand back," he warns, as he loosens the bolts on the hatch at the bottom of the barrel. A stream of paper pulp gushes out from the opening, splattering into the wire-mesh trough below. Water drains into a collection pan underneath to await re-use.

Patterson says he usually just lets it drip at this point, but, eager to show the next step in the process, he presses on the pulp, forcing out most of the water, then scoops it out of the trough and into a nearby wheelbarrow. It's time for the "binder," a little straight cement. He scoops out a small measure of the gray powder and sprinkles it over the pulp. That's it? A little sprinkling of cement is going to hold together blocks used for construction?

Patterson blends the cement powder into the pulp by hand, with a hoe. Not quite satisfied with the mix, he tosses in another couple of tablespoons of cement.

"Each batch is a little different," he says.

The norm is to produce 40 blocks, each 10-by-16-by-4 inches, out of a single small bag of cement. Patterson's Padobe blocks weigh about eight pounds each. They're no lightweights in performance, though, able to bear 85 pounds per square inch.

Now it's time to shape the blocks, which he turns out with the aid of a custom-built rectangular metal frame. Patterson sets the frame down on a piece of plywood placed on a wooden pallet. He throws handfuls of the yellow-gray mix into the frame, pokes and pats it by hand down into the bottom and corners of the mold, then rolls a metal pipe-like instrument, sort of like a rolling pin, over the top, making a uniform, flat surface.

He pulls the mold off the wet block, then goes through the forming procedure again, producing another.

His yard has become a curing space, pallets and pallets of gray blocks drying in the hot New Mexico sun. He's put his blocks to good use in a hand-built dome-style laboratory workshop, where he tinkers with other inventions.

"I'm working on a refrigerator fan right now," he says, "one that uses half the energy of a so-called normal fan and is more effective." One more small step toward reducing global warming, he adds.

It's easy to make blocks in any shape, he says, hence the domed workshop. The finishing stucco coat seals the blocks, protecting them from moisture that would otherwise cause them to break down.

A step inside the dome, through the custom-shaped rounded door, reveals a comfortable atmosphere. A computerized panel on the wall reports that although it is well into the 90s outside, the temperature inside the domed lab is only 82 degrees. In fact, the panel shows that the temperature inside the small dome has fluctuated only four degrees over the past 24 hours. With an insulation factor of R-36, Patterson's Padobe blocks seem remarkably efficient.

The latest batch of bricks, curing on the pallets, will soon be used to build a new shed, he says. OK, a laboratory and a shed are nice, but what about larger projects—you know, real live houses?

"Oh, about half my house is made of this stuff," he says with a wide smile.

Turns out Patterson has built a three-room addition onto his house using Padobe block. On the outside, there is barely a noticeable difference between the old and the new, as he shows where the Padobe addition starts. Except, well, the new is actually more perfect.

Inside, he shows off an attractive, adobe-style living room, master bedroom and full bathroom addition, blending seamlessly with the rest of the dwelling. Patterson enthusiastically removes a picture from the wall. Behind it, framed in a wooden square mounted on the wall—a Truth Window, builders call it—is evidence of the addition's unique Padobe construction.

Cost for the addition: $8,500. That's total materials, start to finish. As for his labor cost? Well, this was a labor of love.

Turns out, building with papercrete-type products is surprisingly affordable. One Web site says homes and other buildings of up to 3,300 square feet have been built with papercrete, not including labor costs, for about $25 a square foot.

But rules about how much paper can be in the mix are sketchy. It's hard to find standards that even define which binders are acceptable for permanent structure construction. While generating interest and even becoming popular abroad, paper-based building products still have a ways to go in the commercial sense.

"I think once it's accepted (by the public and code officials), it'll take off like crazy," Patterson says.

In the meantime, Patterson is sharing information with individuals and construction firms interested in using the product and technique, getting the word out about his lightweight, durable Padobe blocks. Sure, he'd like the product to have wide acceptance and be able make a bundle of money off his patented formula and technique. But just as satisfying, he says, would be the knowledge that he'd be keeping tons of paper out of landfills.

"In this area alone, we throw out enough paper to make 1,500 Padobe blocks a day, seven days a week," he remarks. "With an average home taking 6,500 blocks to make, I don't know, do the math." Turns out it's more than 84 houses a year. "That's a lot of paper we're throwing away. Wouldn't it be better, smarter, to build something with it?"—Donna Clayton Lawder

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