So What’s This Stuff Called Adobe?

Now take a deep breath and relax. This one is really simple. Adobe is pretty much the exact same mix of clay, sand, water and straw. It’s mixed the best with your feet the same way as cob. If you add more straw then the mix has more insulation but is a little weaker.

That was the easy part. Now the differences between cob and adobe is how they are prepared and used. Cob is rolled into balls or logs and cobbed or cobbled together and shaped to form a solid mass. Adobe on the other hand is formed into bricks, then sun dried and used like a brick.

So this process is fairly easy to do. You start with a form made of wood. Usually a 2×4 or 2×6 is used and you can make a form for one brick or many. How many bricks to put in a form is really up to you. If you will need a lot of bricks or are making large batches of cob/adobe mix then a larger number of bricks in the form goes faster. If you are one person doing this alone then make a smaller or single brick form so it’s easier to handle.


So you take whatever size form you decided to make and place it on clean flat ground. Keep a small bucket of water near the form because you want to wipe on some water onto the form before putting any mud mix in it. This will help the mud to release from the form. Now fill the form with the mud mix starting with the corners and finish by using a screed, or board, across the top and flatten the mix in the form. Wait a minute or two and then lift the form. Remember that you don’t want the mix to wet or when you lift the form the bricks will sag and run.
Now here is the hard part about adobe. You have to wait. You wait a between one and three days and then turn the brick up on the thin edge. Then you wait for between one to three weeks of drying time before you can start to build with them. At this point patience is a must.
One more note about the forms. The 2×4 makes about a 3 1/2 inches thick brick where as a 2×6 makes a brick about 5 1/2 inches thick. Why is this important? Well a thinner brick dries faster but a thicker brick takes fewer courses of bricks. Also take into consideration that the adobe brick should be larger in size than the red clay bricks. In this project the walls of the cupboards will be about 8 inches wide, 12 inches long and 3 1/2 inches tall. If you plan on using the adobe bricks for a building then the blocks should be larger. The standard size for building walls is 10 inches wide, 14 inches long and 3 1/2 to 4 inches thick.