How to Make Mudbricks

Mudbricks are used the world over as a simple building material. They don't need to be fired in a kiln and can be dried out in the sun. A well maintained mudbrick that is sealed and covered by a roof can last 50 years.

Materials:

Dirt
Manure
Straw
Water

More Advanced (Optional)
Wood: 2 2x4x8's
Wood Screws: 2-1/2 inch
3 to 4 foot long spare stick or block of wood

Tools:

Bucket
Shovel

More Advanced (Optional)
Drill
Drill bit
Hand Saw

Process:

I figured out this process after watching the opensourceecology.org process on how to make a compressed earth brick (CEB). I wanted to make something a little more primitive, because I figured some locations would not have the materials available to construct a brick press. Here are the two processes I came up with:

Process 1: More advanced method - quicker and sturdier brick

• Build a brick mold out of wood. Make the your walls sturdy and at least two blocks thick. I interlaced my wooden blocks and used 3 screws per joint to ensure it would maintain its form under a lot of pressure. The entire form is a foot long by 9-1/2 inches wide by 5 inches tall. 
• What you can't really see in the picture is the base, which are just standard 2x4s laid flat instead of on their sides. The base is 1/2 inch wider than the form so it has a little edge around the bottom to increase stability. The base is also screwed in - interlocking and securing the rest of the form. It really ties the form together. 
• Also, make sure the center is as wide as a  standard 2x4. My center hole is 6 inches long by 3-1/2 inch wide by 5 inches tall.

• Cut a block the same size as the hole in your form. Mine is a standard board 2x4 (1-1/2 by 3-1/2) by 6inches

• There, now you have a form. Now it's time to get your construction materials. We collected ours from a muddy section of a horse pasture because it had all of the materials (dirt, manure, straw) we needed already together. Look for an area that is damp - not dry but also not too muddy. The top layer of the soil is probably too dry, but a few inches into the earth produced some good damp soil and we didn't need to add extra water to the mixture. The material smelled earthy, but not overwhelming.

 

•  Now moisten the inside of the mold a little bit of water. Then, place the mold onto a hard, flat surface and put the material into the mold. You want to fill the mold with material all the way to the top so that the dirt is flush with the top. Then cover the hole with the spare block.

 

•  Next, stand on the block (or have a friend stand on it for you) to keep the mold in place, then lightly hammer the block down into the hole with your rubber mallet - compacting the material within the mold. It's difficult to line it up at first, but after the block is in about 1/2 an inch, you can really hammer away. Try to keep the block level.
• After the block was securely in the mold, we used a longer so that we could stand up. This provided more leverage and room to hammer.

• Hammer down until the block will no longer go down any further. It should be just about flush, or a little lower than the top of the mold.
• Lastly, flip the mold on its side, and lightly hammer the block the rest of the way through the mold, pushing the brick out the bottom.

  

There ya go now you have a brick! The brick is semi soft, slightly cool to the touch, and incredibly dense. Now, let it dry in the sun while you make more!

Process 2: Primitive method - less materials required

This process is much simpler but makes a brick that is lighter and more prone to cracking and erosion.

• Collect Material - dirt, manure, and straw. Again, we took ours from a horse pasture.

• Add water to the bucket

• Mix vigorously until you have a cake-like batter

• Pour the mixture into buckets or into the cinder block holes if you have them. I found that buckets work better, because the cinder blocks dry out the edges.
• Let sit for two weeks in the sun. The mud will shrink slightly and be fairly easy to remove from the form.

And there you have it! Mudbricks!