How to Make Adobe Blocks for Houses

Making adobe blocks for houses is a simple process but is labor intensive. The large number of blocks needed for a home, the long cure period and the potential for needing hired help can make the project expensive, even though the materials are cheap. Adobe blocks are heavy; 5-by-12-by-18-inch block weighs almost 60 pounds. If you live in a relatively dry climate, making your own blocks is an eco-friendly choice. Not only are the materials sustainable, but the finished walls will provide superior insulation.

Things You'll Need

• Soil
• Lumber
• Sand or straw
• Shovel
• Water

Instructions

1. Check the soil you intend to use to make the adobe blocks; it must be less than 30 percent clay and at least 50 percent sand. Go to the county extension office or ask someone with experience about the composition of your soil. If you don't have anyone to ask, make some sample blocks six months ahead of the start of your project.

2. 

   Build forms for your blocks. The form should be the size and shape of the finished blocks and be supported by longer sides with a brace between them on each end. For a 4-by-8-by-16-inch form, two sides would be 20 inches long, separated by two 8-inch pieces of wood 16 inches apart.

3. Create your workspace. It should be near your source of soil with a large, flat space for drying the blocks. Sprinkle sand or straw over the brick drying area. Dig a hole about 2 feet deep and about 4 feet wide. Soak the pit with water for at least 12 hours before you begin.

4. Put a few shovels full of dirt into the pit and add water, mixing as you go, until you have a stiff consistency. Fill the forms with the mixture. Make sure the corners are filled. Remove the forms, and let the blocks sit for at least three days.

5. Turn the blocks over to continue the drying process. Protect the blocks from rain, but cover them lightly because the wind and sun are important to the curing. The blocks will be ready to use in about 1 month.

Tips & Warnings

• The forms can be rinsed off and reused immediately. Plan your block making for a time when excessive amounts of rain are unlikely. Mixing in straw or manure doesn't add strength to the blocks but may be customary in your area.

• Don't build with adobe blocks in areas that are subject to heavy snowfall or long periods of rain.

References

• Adobe Block Basics
• Adobe Block How To

Resources

• Adobe Home Building Considerations
• Hybrid Adobe Homes
• How to Build a Box