Unfired Earth is an ancient and traditional building material with many benefits that is suitable to use for building homes in all climates and all regions of the world. Though many homes made out of unfired earth exist on all continents of the earth, there are relatively few new buildings being built this way. Within the constructs of the modern shelter industrial complex, unfired earthen construction has been replaced. One reason is that the process of mixing and laying the mixtures, is considered to be "labor intensive" which makes it cost prohibitive. At the same time, a small yet growing number of people on all corners of the planet are finding creative ways to revive unfired earthen construction in order to enjoy it’s many benefits without the high costs. For example by getting a large group of volunteers to make and lay the mud mixtures together in a festive way, the "expensive labor intensive" component is transformed into a fun community bonding activity. Since the earth can be dug right out of the ground in almost all sites, the costs for materials is very low.
photo from www.kleiwerks.com
The benefits of building with unfired earth include:
When combined with food and music and other festivities, it is a fun activity that can involve everyone from the community.
It is easy to learn.
It is non toxic.
It is a healthy activity.
It uses a readily available and inexpensive material.
It is non polluting.
It is very durable when mixed correctly. Examples of unfired earthen buildings include the 1,000 year old Pueblos in the Southwest of the USA, the Great Wall of China, the 1,000 year old city of Timbuktu in Africa, the 1,000 year old buildings in the Middle East and the 500 year old unfired earthen "cob" homes in Devon England. It has very strong insulating properties to maintain a comfortable temperature inside.
It is suitable for making curved and rounded structures that have aesthetic appeal.
Above is a picture of the Djenne mosque in Mali Africa the largest earthen structure in the world, just down the river from the ancient earthen city of Timbuktu (taken from www.sacredsites.com) "Every spring Djenné's mosque is replastered. This is a festival at once awesome, messy, meticulous, and fun. For weeks beforehand mud is cured. Low vats of the sticky mixture are periodically churned by barefoot boys. The night before the plastering, moonlit streets echo with chants, switch-pitch drums, and lilting flutes. A high whistle blows three short beats. On the fourth, perfectly cued, a hundred voices roar, and the throng sets off on a massive mud-fetch. By dawn the actual replastering has been underway for some time. Crowds of young women, heads erect under the burden of buckets brimming with water, approach the mosque. Other teams, bringing mud, charge shouting through the huge main square and swarm across the mosque's terrace. Mixing work and play, young boys dash everywhere, some caked with mud from head to toe."
Pictures of unfired earthen construction technology from different climates from around the world.
Below is a picture of an unfired earthen structure in the legendary 1,000 year old city of Timbuktu in Mali Africa. (from www.danheller.com) North America. Below are some pictures of unfired earthen home in USA and Canada where it is cold and rainy to illustrate that unfired earthen building is suitable for all climates.Interior of unfired earthen home with limestone plaster in Oregon USA where it is cold and rainy (from www.cobcottage.com) Unfired earthen home in snow in Canada (www.cobworks.com) The same home different season Interior upstairs of same home Interior downstairs of same home Below: Unfired earthen home in North America with limestone plaster. from www.cobcottage.com Hand sculpted furniture. Rebuilding the soul of humanity, one wall at a time. Below, (South Africa) handsculpted unfired earthen home in, walls, fireplace, furniture, floors and next below check out the kitchen sink! (from www.cobworks.com)
Below, modern earthen home built in San Cristobal de Las Casas, in the mountains of Southern Mexico. below from www.cobworks.com Below is an example of a 500 year old unfired earthen home with reed thatch roof in Devon England, a cold and wet region of the world where there are many thousands of such structures between 700 and 500 years old. (www.cobcottage.com)
Unfired earthen ("cob") home in New Zealand (above) Built in 1855, this building has withstood three major earthquakes that leveled the rest of the town.. Slates for roof imported from Wales. (from www.cobcottage.com) Below is the longest continuously inhabitated structures in the USA. These homes are 1,000 years old. The residents do not pay rent or mortgage payments since they are living in homes built by their ancestors, that are made to last. (Taken from www.taospueblo.com)
1000 yr old Taos Pueblo village. A village is a sustainable way to live where homes are clustered together to create community and the land around can be preserved for agriculture and wildlife.
This is a photo of an owner built house that was built in 1996 for less than $2,000 USD. It is amazing what we can do when we come together in the spirit of cooperation. This group of people have created a blueprint for the extremely low cost, energy efficient house. The plans are available to all. Check out their amazing work at http://www.sustainable-futures.com/housing/housing4.html The pioneers of this movement are creating a portal into a new reality outside of our current all pervading "shelter industrial complex" whereby in order to have shelter over our heads we must work forever and enroll all our future generations into eternity into a system that is based upon and built upon unfairness and injustice. Mortgages support and uphold banks which support and uphold interest rates and currency which support and uphold nations and corporations which support and uphold the unfair extraction and distribution of resources and every other related injustice known to mankind. This movement is responsible for the creation of beautiful and durable homes that are built at an extremely low cost. One of the most beautiful homes I have been in was built for less than $500. It's amazing! Unfired earthen building block mixtures, the various techniques and their applications. The basic mixture for load bearing walls, furniture, floors and plaster is about 15-50% clay, 50-85% sand and then about one third of the total mixture is fibrous waste material such as straw. Non load bearning walls can have more fibrous waste material. For example, straw can be soaked in a clay, sand, water mix and then pressed into forms and dried out into large building blocks that are stacked and plastered over.
Most earth under the topsoil is a blend of sand and clay of varying proportions. In many cases there is enough clay content (at least 20%) in the earth under the topsoil to make into a suitable building material. In order to make this sand clay mixture suitable for building it needs to be reconstituted into one homogenous mixture so that each grain of sand is bonded by surrounding clay. Our method is to dig a hole beneath the topsoil, remove topsoil, add water and make a mud mixture with many people stomping with their bare feet. Fibrous waster material and extra sand are then added and further mixed with more bare foot stomping mixing. The more the mixture is mixed, the stronger the building material.
Optimum durability and temperature is achieved by taking into consideration the climate of where you are building, the thickness of each wall, the positioning of openings, and varying the proportions of sand to clay and fiber in the building blocks that make the walls. This knowledge of ideal wall thickness and mixture ratios is typically learned by a culture/community over time through trial and error and adjustment. The basic mix of sand,(50-80%) clay (20%-50%) and straw is also a general one size fits all formula from which to start.
In the sand, clay fiber mixture, the sand is the filler, the clay is the bonding material and the fiber adds body, tensile strength and insulating properties. A good mixture is equal amounts of all three ingredients although these ratios can be modified to a large degree. If the earth you are using has more than 50% clay content then you will need to add sand. If the earth has more than 80% sand content then you will need to add some clay rich soil to the mixture. If you dig a big enough hole then the chances are that you will find the right mixture overall even though some areas might have more clay or sand than others. If you only have a small hole dug and the earth looks the same throughout and you want to determine how much clay is in the earth you can take a sample in a jar and add water and shake it up vigorously 3 times a day for 3 days. By the third day the mixture should settle into its separate parts with a layer of clay and a layer of sand and a layer of silt. As long as you have roughly 50% sand and 50% clay then you are OK and then you can add fiber up to about one third of the total mix. Fibrous waste material is not to be confused with hay which is what animals eat. Fibrous waste material has no food value for animals and examples include wheat straw, grass straw, corn husks or rice husks. The dried manure of grass eating animals such as cows can also be used and is especially useful for the plasters because the very small fine fibers interlock to create a seal and a smooth finish. The oils from the manure also help seal the finish.
Cob, adobe, mud brick building, rammed earth, wattle and daubing, slip straw and earth covered straw bales are all various forms of unfired earthen construction technology. Below is a description of each that identifies their differences.
Cobbing/Monolithic adobe/ Monolithic earthen building/ “packing wet blobs”: The sand, earth and fiber mixtures can be made into blobs or “cobs” and laid wet in place to form one monolithic building block that is load bearing. The benefits of this method are that the ingredients can be taken directly from the site and a very strong building results.
Adobe /Mud or sundried earthen bricks: The same ingredients can also be laid and pressed into brick making forms and dried in the sun to make square bricks that are then mortared together with wet mixtures of the same ingredients. Also load bearing. The benefits of adobe are that you can make use of a large labor pool and build up very high at one time. The bricks are said to form a weakness against very large forces such as an earthquake.
Rammed Earth: The rammed earth technique sets up a mold or form that the earthen mixtures are rammed into using pressure and left to dry. The form is then lifted up and the mixtures are once again rammed down between the form to build the wall up. Also load bearing. This method shares the benefits of cobbing. Making and using the forms is more complex than cobbing.
Wattle and daubing: uses a load bearing wooden frame that holds up the roof that is in-filled with smaller pieces of interlocking wood and then the earthen mixtures are applied over that. Non load bearing. Post and beam frame required.
Slip straw is the process of taking straw and other fibrous waste material and soaking it in a wet sand and clay mixture and then pressing the wet fiber into molds that are dried and used as building blocks for non-load bearing walls such as room dividers or post and beam in-fills. Non load bearing.
Strawbale building: bales of straw are stacked on top of each other and covered with an earthen mixture and plastered for non load bearing walls between a post and beam frame. Non load bearing.
Any combination of these methods or techniques can be used for each circumstance.
------------------------------------------------------------------------------------------------------------------------------------------------ This program suggests the process of using the festive music, food, and dance process to make wet blobs or cobs and laying them in place up to the maximum wet height for that day. (typically about 1-2 feet high). Then the remaining wet mixture is put into forms to make bricks that are dried in the sun and laid in place on future subsequent days OR formed into blobs that are kept wet enough to be molded into the building the next day when the already laid walls are dry enough to keep building on.
