Reflections on a Compressed Earth Block Construction Workshop at Instituto Tierra y Cal

By Bawshkeengwabigun (Tara Chadwick)

June 1, 2011

Part 1

For me, it's like learning how to plant corn... something I never really did, yet it's there, in my memories from seeing it standing there, strong and vibrant, living through the work of my grandparents and those before.  Using the basic elements, the soil, the sand, the clay from the earth, and the water... and simple tools made of wood and metal.

Plastering the wall of compressed earth block, for me is like me... a link in the chain of human existence, bridging the past with the future.  Nopal cactus for a binder.  Limestone for a stabilizer.  Human work shaped by a machine... to make the bricks.

Bricks formed from the substance of our mother the earth, to protect us and allow us just a little bit of comfort as we work to restore our daily actions to harmony with the natural cycles of our surroundings.  Earth compressed into blocks, plastered with earth, nopal juice and water.  Plaster from the earth, in harmony with the earth, tinted in the colors of the earth... a pathway weaving technologies, ancient and modern... to lead a way to the future that minimizes our need for heating and cooling, that uses local, natural materials, that forms a solid foundation on which our future can take shape.   A foundation of respect, harmony, and dignity for people, the unborn and mother earth as well.

I can see our restoration archaeology taking shape from the natural plasters and stabilizers around us... using natural tints and elements....

I can see our neighborhoods working together to build homes for each family, modest yet strong, safe, but open to the natural breathing process of the earth.

I can barely wait until our children grow with this technology, to integrate the future technologies of their time into this structurally sound foundation, to form adaptations that we have yet to imagine.

For me, this learning is like returning to my homeland, retracing my steps and reclaiming a long lost treasure that belongs to me and everyone who chooses to notice its incredible potential.

	Clay, lime putty and nopal juice	Mixing the plaster base coat with hay	Plastering an Earth Block Wall

Part 2

It’s been a week now since the tornado hit North Minneapolis.  Electricity has been restored to the neighborhoods, although many homes are still without the infrastructure to access it.  Flooded basements are starting to recede, and the many, many trees that have fallen onto roofs, cars, streets  and walkways are beginning to be cut up, carried and trucked away to city compost and biomass burner sites.  Families are starting to pick up the pieces of their lives and do their best to continue on with their daily tasks, be it searching for a new place to rent, one that has not had its roof torn off, applying for emergency assistance, or sifting through their belongings to see what needs to be tossed out and what they can keep.  Many adults and children are still jumpy, frightened by the sounds of wind through what trees remain, or pulling at the loose roof tiles just above their heads.  The small ones ask, “Do we need to go to the basement again, Mommy?” While the adults and older children pray for no rain on the tattered rooftops.  Rebuilding our lives after disaster is a long, slow process.

Uprooted tree in front of Kwanzaa building on 37th & Bryant

As the residents of North Minneapolis face the worst, they also shine their light of common humanity among one another, building unity and strength in ways that we often see only in the crisis and recovery stage of a natural disaster.  Old school values, neighbors helping neighbors.  People pulling together because we’re all in it together.  This type of urgent crisis stirs something instinctive in the human spirit, an ancient memory that, if we work together, we can survive this.

At great personal and economic cost, the winds have cut through layers of our coverings to show us something that perhaps we forgot we have within our possession: the will, the confidence and the ability to work together to solve our problems. 

This is the human value that is so important for us to recognize, develop and maintain in this time in which we are all learning how very precious the life on our planet may be.

This is the value that will propel us to decision making that includes everyone, not just the home owners, not just the home renters, not just the city council, not just the voters.... Our realization that our basic survival depends on good decision making that is based on longevity and common sense over development plans and short term profit margins… harmony and balance over domination and greed.

This very moment, we have the opportunity to explore and develop our relationship with this value, more so than at any other time in the history of this community.  It is an opportunity that we advocate utilizing to fullest extent possible.  Now, as we see the insides of our humble or luxury homes ripped apart, tar paper and sheet rock exposed to the elements... all that we hold sacred, we thought safely inside, now unprotected from those elements that are still so basic to our survival.

We advocate taking this moment to look critically at the homes, families and community we have constructed around us over the past few hundred years.  Let us look at our options and opportunities, now, while we are without, so that we might make the best possible decisions about how we will rebuild.  What will we use to protect ourselves with now and into the future.  When the next big wind begins to blow, what is it that we and our children will depend on to shelter and protect us?  What is it that we are building?  Exploration and research into what other people are doing around the region and around the world will help us to feel confident that we are making informed decisions, that we have educated ourselves to the full extent possible, and that the decisions that we make together, as communities and families are the best decisions that we can make based on the research that we have done together. Join me as we take a brief look at one such area of research:  the construction of a residential dwelling using compressed earth block construction (CEB).

	Lime, clay & sand mixture...	..for stabilized earth block...	...pouring it into the CEB machine!

Compressed earth block is a modern adaptation of an ancient building technique that is often referred to as adobe construction, and has been used throughout human history in all parts of the world, from the far east, to the far south, to the Midwest.  Even in the early days of colonial settlement in our region, compressed earth was often the favored method of dwelling construction, since it utilized readily available natural materials, and followed shapes that occur naturally in this environment. Modern compressed earth block also utilizes readily available natural materials (sand, clay and an optional addition of limestone) but can take on any shape since the blocks are formed by hydraulic presses with straight, even sides.  It is a modernized, ancient wall system that can be adapted for any climate, any architectural design, while maintaining harmony with and minimal degradation to the natural environment during construction and manufacture.

How do you do it? Once you learn the basics of CEB construction, anyone can build or help to build a CEB structure.  Some specialists will still be required (plumbers, electricians, someone who knows how to lay the foundation and bond beam, and a foreman that is trained in CEB construction), but the bulk of the work is easily learnable and everyone can participate. A community demonstration project is a useful way to provide a valuable experiential/ service learning opportunity, as learning by doing is often the most effective way to introduce knowledge into a community.

	Compressed earth blocks	Pouring on thin slurry	Smoosh 'em in!

Part 3

No where is the secret, crucial ingredient of earth block construction more evident than in the preparation of the final stages of the building … the finishing plaster and paint. Although it’s there in every phase, from site and soil selection, to mixing, to block laying… there is something just a little more obvious about care and love that goes into the final finishing coats that protectively layer the earthen blocks in durable yet breathable natural materials, that must be applied with skill and strength, balanced with creativity and gentleness.

The glue that truly makes this construction process amazing is something that the construction workers may or may not realize is even there… like we may or may not know the chemical processes that bind the limestone with the clay after 28 days… or the molecular structure of the nopal juice that allows it to adhere the elements of the natural paint with the plaster… 

Beside the application skill, structural knowledge, and chemical mixtures, there is in this compressed earth block construction method, the unmistakable addition of love to every block, every course, and every layer of the structure that is being molded, from the basic elements of the earth, through the hard work of the people contributing, toward the good and safety of a human family or community and representing safety and sustainability for us all.

	Applying natural paint	The arch!

For more info about Compressed Earth Block Construction and Instituto Tierra y Cal, visit http://www.institutotierraycal.org/.

To learn how CEB is being used to build an earthquake and hurricane-resistant school in Haiti, see Partners In Progress: http://www.piphaiti.org/Deslandes.html.