‘Stunning’ earth block technology employed
By: Paul Weideman
Published online: Sunday, August 05, 2012
Appeared in: Home, Santa Fe Real Estate Guide
Edition: August 2012 Vol. 15 No. 5
Also by Paul Weideman:
This alternative building method seems just too simple.
A worker digs soil using a Bobcat loader and dumps it
into a trailer-mounted Earth Press machine. Each minute,
four or five blocks of compressed earth pop out. A roller
conveyer takes them right to the spot where workers are
stacking them to build a wall.
In June, architect and contractor Ed Boniface, Boniface
+ Associates, marveled at the process as a ranch house he
designed went up near Puerto de Luna, about 15 miles
south of Santa Rosa.
Neither rebar nor mortar was necessary. “When the earth
is compressed with the hydraulic press in the machine, the
moisture on the surface facilitates adherance,” he said. “This
thing puts out 2,400 blocks in a day. These guys are laying
up walls as fast as they can. It’s absolutely stunning.
“I was terrified at first at this idea of just stacking stuff
up, but I contacted the State Construction Industries Division and the more research I did, the better it all looked.”
The walls are now complete and Boniface’s crew is at
work on all of the other elements of the 5,300-square-foot
ranch house for the clients from Germany. The owner is
Michael Behrens, a physicist and businessman who did
research and discovered the technology of compressed-
earth blocks, or CEBs. The company that produces the
Earth Press machines is Adobe International Inc., located
in Milan, west of Albuquerque.
The CEBs are very dense, and heavier than adobe.
“People talk about adobe as being very environmentally
friendly, green, but you have to get the right mix, mix it
up, then there’s the backbreaking labor of setting it in the
wooden molds on the ground, then flipping the bricks,
then turning them on edge, then you have to pile them on
palettes and drive them to the job site.
“Also, with adobe you’re limited in how many courses
you can do in a day, because the weight can squish out
mortar and you need to let it dry.”
The Earth Press machine delivers the blocks — each one
8 x 12 x 4 inches — near the wall being built, and you can
move the machine to follow the wallmaking process. The
exterior walls for the ranch house are 20 inches thick and
the interior walls are 12 inches.
In the typical CEB building, once the the walls are
complete, a steel-reinforced concrete bond beam is poured
around the wall tops to add strength and anchor the roof
structure. Channels for wiring and plumbing are cut into
the walls, then nylon or wire mesh is nailed onto the walls
prior to stuccoing outside and plastering inside.
Like adobe bricks, compressed-earth blocks provide
great thermal mass but little insulation value. “CID requires
that we add insulation and we’ll do sprayed-foam insula-
tion on the exterior,” Boniface said. “One thing that makes
me sleep better is that when you spray foam, it also helps to
tie the wall together, plus it tightens up the house. This will
be pretty air-tight.”
CEBs offers building-design possibilities similar to what
you have working with adobe. And of course both strate-
gies use earth as the raw material. “The head guy in the
Native American crew for the ranch house project looked
around and about 20 feet away from the house site, he said,
‘ This dirt will be fine.’ I had this vision that we would have
to mix different kinds of earth, but that was it.”
Henry Elkins, founder of Adobe International, said his
company has worked in Africa and South America, as well
as in the United States, and the local dirt has always been
adequate. “It requires a good clay content and about 10
percent moisture,” he said. “When the dirt is first dug, a lot
of times it’s pretty close to what we need. If it’s a little dry,
we’ll sprinkle the dirt with water.”
Adobe International was established in 1980. Its resumé
includes a sale of 10 Earth Press machines to the govern-
ment of Panama for affordable housing. People in Zacatecas, Mexico, built 500 homes over four years, using four of
the machines. And in Mali, Adobe International machines
are being used to build schoolhouses.
Boniface is already
planning a second CEB
project: a home in Tesuque.
If, in the future, he were
to decide to be “Mr. CEB”
in his work as a contrac-
tor, he will have to decide
which of the three Earth
Press models to purchase.
They’re priced between
$25,000 and $50,000 — the
puts out 10 blocks per minute. Purchasing an Earth
Press sounded like a good idea to the new owners of Creek
Ranch on the Pecos River. That way, anytime they want
to add an outbuilding, they can just get a three-man crew
together and fire it up.
For Boniface, the best part of the Creek Ranch project
came after the walls had all been raised. “The Germans had
a richtfest on June 30. In Germany, the entire community
shows up when the last beam is in place and they tack an
evergreen on top and they have a richtfest with food and
drink and the architect is supposed to talk, thanking the
owner for providing work for him and all the workers, and
thanking the workers for what they have done.
“It was so much fun. There were probably 150 people
there sharing in this almost religious experience. We’re so
used to slamming houses up and moving on, but this was
all about family and community.”