Adobe brick is one of the least expensive building materials. Made for thousands of years, adobe brick has remained a consistently popular building material in hot, dry places. Making your own adobe brick is very easy.
Step 1 - Get Your Soil
Before you can make any type of adobe brick, you must find the best quality of loamy clay soil. You can usually find this type of soil on the top or side of a natural hill.
Avoid any type of soil in a dry water bed or low lying areas that can be flooded. This soil is full of rocks and gravel and contains no clay. The clay is the agent that makes the best bricks.
Step 2 - Test the Soil
If you are not sure about the soil you want to use, there is a way to test it out. Fill a glass jar about 2/3 full of soil. Add water until the jar is full, and shake it for about 2 minutes. Set the jar down and let it sit overnight.
When you check the jar, the soil should be broken up into two distinct bands of dirt. The sand should be settled on the bottom with the clay on the top. There should be more sand than clay. A ratio of about 70 percent sand to 30 percent clay is ideal for making adobe brick.
Step 3 - Prepare for Bricks
Adobe bricks will take a few days to dry and harden. You will need to store them in an area that will be protected in case of rain.
Near the storage area, dig a hole 4 feet long, 3 feet wide, and 3 feet deep. This is where you will mix the ingredients to make the adobe brick. Fill the hole with water and let the water drain out. This will take at least a day to do. The water is important so the walls do not crumble in while you are mixing the clay soil.
Step 4 - Build Brick Form
Use the 2x4 lumber to build a brick form. Cut two pieces to 5 feet in length. Cut the other 2x4s down to 14-inch lengths. Nail these to the 5-foot pieces every 10 inches to create a structure that looks like a ladder.
Step 5 - Make Adobe Bricks
Fill the hole halfway with the clay soil and enough water to make a stiff mud. If you like, you can mix in a small amount of straw.
Shovel the mixture into the brick form. Fill each separate form completely and level off with the shovel. Make sure there are no air pockets or gaps.
Let the bricks set and then remove the form from them. Repeat the process in a different area.
Step 6 - Dry the Bricks
Leave the adobe brick where they are while they dry in the sun. When the edges turn white, they are ready to be moved, but not used. Turn them on their edges to completely dry out and harden. This process could take at least 3 weeks.