Clay bricks have been used for construction for thousands of years -- and while some advances have been made, and mechanization has made the process easier and faster, the essential technique for making bricks from clay has remained unchanged. The process requires only a few basic tools and materials, and can be accomplished just about anywhere. This is why clay bricks are still used to build houses and walls all over the world -- from handmade clay bricks in the developing world to redbrick blocks common in modern construction.
Dig up clay soil with a shovel to use as the material to build the bricks. You can identify clay soil because it is sticky and gummy when wet.
Grind the clay soil into a fine powder or paste using large, fat stones as "grinding stones." This will assist in the bonding process. Some clay soil is already at the right consistency, but grinding will generally improve the end result of your brick building.
Mix the ground clay soil with water to make a thick malleable paste. Traditionally, clay bricks were molded by hand or with wooden tools. Today, many clay bricks are made in purpose-built molds. Whichever molding method you use, aim to produce clay bricks of the same size and shape.
Leave the bricks out in the sun to dry, or dry them in an oven to remove the moisture. Traditionally, brick builders lay bricks out in the sun to dry -- and this is still a method used in many countries as it does not require fuel or electricity.
Fire the dried bricks in a kiln. A kiln is a type of ceramic oven that heats the contents to a very high temperature for a number of hours. This will alter the molecular bonds of clay and bind it to the other molecules -- making very solid bricks as a result.