PRE HISTORY Clay houses are found all across the whole world in every continent with tropical climates, very common with hunter and gatheres also permanent farming cultures. Ceramic houses are buildings made of an earth mixture which is high in clay, and fired to become ceramic. The process of building and firing such houses was developed as early as 15 000BC just before the dawn of farming. This way of construction souly includes huts with thathed roofing being extremely common.

The common clay hut house tends to also be a roundavel, in the construction of clay huts the base of the foundation what would become the floor and also lower walls of the hut roundavale is normally dug to create a sunken structure of a roundavale so it would be easier to build a large wood and clay dorm shaped furnace over it.

The benefits of building a clay hut is common due to the need of not having to worry about frequent maintenance of the hut versus a typical mud hut which needs frequent maintenance over a period of time. Clay huts became favoured due to their durability to last longer than mud huts made from dagga and wooden poles.

History of the Ceramic huts method

As mentioned in the introduction clay huts can be found to go back as early as 15 000 BC in what is today Tanzania by what seems from archeologist to be from a group of hunter gatherus that settled the area what is the southern highlands in Tanzania. Clay houses seem to be very common in hilly areas mainly because if you check huts which are constructed in mountainous hilly areas they normally have a sancken floor the main purpose for this is hest insulation since higher the elevation the colder it gets. Construction of clay huts was seen as durable and long lasting versus pole and daga hut.

Building and firing

In the modern world today around the common earth used for building ceramic houses is essentially a type of adobe with a higher clay content and fewer impurities. The earth and water are mixed until the substance has "the consistency of bread dough"[1] The clay/earth mixture is worked into forms, and the blocks dry over a period of one to two weeks. A mortar is made with a "flux" (glass, soda, or colemanite) to help fuse it.

The adobe blocks are laid so that the joints are staggered. There is no mortar in the vertical joints to allow for expansion and contraction during firing. Rammed Earth and Mud Pile can also be fired, but must be fired from both sides because of the thickness of the walls. Building with stiff wet mud, like a potter, allows for thinner walls, and the possibility of incorporating flue systems into the walls. Arches can be formed by stacking non mortared blocks as form work, and removing them after firing.

The firing system used is based on the availability of fuel and local know how. In Iran, village kilns used oil for fuel, so a simple, gravity flow oil burner could be used to fire each room. Flues are created (either integrated into the structural, or made for removal) and openings are closed with un-mortared brick. Joints are covered with a thin layer of mud plaster. The burner is placed at a low opening with room for air circulation, but protected from wind.

During the early stages of firing, 200–900 °C (392–1,652 °F) water vapor escapes through the flues located on the roof. Once the steam escapes, roof flues can be closed and heat will circulate the room before escaping from floor vents. This is when the room is heated to at least 1,000 °C (1,830 °F) and the adobe is baked. After the firing, only the ceiling flues are opened to allow slow cooling over at least 48 hours.

The outside walls are finished with either a mud straw plaster, fired brick, or ceramic tile. When finished with mud straw plaster, a thin layer of clay earth and straw is baked on to the structure at the end phase of firing, and a second layer of the plaster troweled on after cooling. When finished with tiles, they are mortared directly over a waterproofing layer such as tar.[2]

Forms and techniques

The primary shapes of a ceramic building, are squares and rectangles with roofs that are arches, vaults, and domes. This is in order to construct the entire structure of monolithic material (cost effectiveness) and also to achieve the tremor resistance and proven longevity of a shell membrane.

Adobe and clay can be sculpted into built-in forms and structures, such as seats and shelving, and fired with the rest of the house.

Adding oxides and different types of sand and clay can create different finishes. The most important mineral oxide in glazing is silica (which makes glass). Low fired glazes are preferable for houses. Glazing should only be done in some places to allow for a room's skin to "breathe." Glazes have even been made with recycled glass bottles. Salt glazing is another way to make an inexpensive finish.[1]

Benefits

There are many potential benefits to firing an earthen house. Firing makes a clay structure water resistant. Ceramic kilns often outlive the earth constructed buildings they are close to. The materials for this type of building are accessible to those with very basic resources. Fuel for firing is the most expensive investment. The hardened membrane of a ceramic dome improves resistance to earthquakes. The structure of a ceramic house improves passive heat use through thermal mass. Added benefits involving the firing process include the opportunity to produce other ceramic goods for use or income, and, when firing an existing house, pest evacuation will occur naturally.

Examples

Experimental fired earth housing has also been constructed using the principles of an ancient Chinese anagama kiln. In the anagama kiln system, a wood fire is built at the base of a slope, and the gases are drawn by a strong draft up the slope through a tunnel. When a dome is constructed at the end of the tunnel out of clay, the hot gases bake the clay structure to ceramic hardness.[3]

See also

References

  1. 1 2 Khalili, Nader. Ceramic Houses and Earth Architecture: How to Build Your Own. San Francisco: Harper & Row, 1986
  2. ↑ Khalili, Nader. Ceramic Houses and Earth Architecture: How to Build Your Own. San Francisco: Harper & Row, 1986
  3. ↑ Martinez, Alice. "Making a New Life: Trial By Earth and Fire." San Diego Earth Times. December 1995


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