I call it dirt. A soil scientist calls it loam. It’s the material that lies below the top few inches of topsoil, comprised of a mixture of sand, silt and clay (particle sizes from largest to smallest in that order). It’s the most abundant thing on the planet and people the world over, for thousands and thousands of years, have been using dirt to build the necessities of life – shelter, grain silos, cold storage, and walls for protection. Without it, it’s doubtful we’d be where we are today. It was the very foundation for the progression of our species.
In fact the Great Wall of China is a six thousand kilometer rock and earthen wall, providing defense to one of the most powerful civilizations in history. Dirt has been used to construct elaborate temples, the palaces of great emperors, and entire cities of skyscrapers, such as the thousand year old structures found in Shibam, Yemen. It was used to render European monasteries, castles and mansions, and it provided, and continues to provide, sound shelter for billions of people all over the world. But dirt is for not without the wonderfully complex clay molecules that allow buildings of dirt to stand for centuries and to defy gravity. So what is clay?
Clay is the product of millions and millions of years of weathering (the action of air, water and sunlight) on the feldspars and micas of igneous rocks (rocks of volcanic origin), grinding them down in a slow but persistent process that has created an incredible abundance of this marvelous and ubiquitous substance. It can be found almost anywhere on earth and if spread evenly across the earth, it would be nearly 2 kilometers thick.
Clays vary in their chemistry and almost always contain impurities. Generally speaking, they are made up of alumina, silica and water with minor amounts of lime, magnesia, soda or potash. Iron compounds, hydroxides or carbonates represent the impurities and are responsible for the rich and brilliant colours found among clays.
It’s the crystalline nature of the molecule that makes clay so incredibly versatile, forming very thin platelets that slide over one another like a deck of wet playing cards. The flat platelets cause clay to be malleable (plastic) and sticky, and explain why no matter how finely you grind sand or silt, they never become plastic. When clay is wetted, the plate-like shape of the ultra-fine particles, along with the electrical relationship between the clay and water, causes a powerful attraction that binds the clay, and anything between it, together. In natural building, clay is the mortar that holds the sand and silt together and this combination is not only a recipe for building affordable and sustainable buildings, but homes that nurture us physically, emotionally and spiritually.
The benefits of clay have been known for millennia. It has always been part of medicine and healing due to its pain-relieving, anti-inflammatory and astringent qualities. Homes built with it have stood the test of time without the problems associated with costly, synthetic, and mass-manufactured building products that are commonly used today.
Modern research, especially that coming from the International Institute for Bau-biologie® & Ecology, verifies the health enhancing properties of living in homes constructed with clay. It helps to regulate moisture, while helping to buffer against the impacts of EMFs (electromagnetic fields) and radiation. In fact, it is well known that Russian scientists would use bentonite clay to protect their bodies from radiation when working with nuclear material. They’d coat their hands and bodies with hydrated bentonite before donning their radiation suits. It’s truly powerful stuff!
Those who treat earthen structures as primitive, inferior & dirty have not experienced the profound magic of dirt. Working with this unpretentious, soft, soothing, malleable, and even life-enhancing substance has been one of the greatest additions to my life. It has nurtured me on many levels, while providing me with a livelihood that is positive and rewarding. As more people reengage with this material, tapping into a rich and beautiful history, we’ll be able to create healthy and durable homes for ourselves and our children and their children. You too can unlock the mystery of this amazing material by getting your hands and feet dirty at an upcoming workshop. You won’t regret it!