Adobe is an ancient building material, easy to make and extremely durable. The adobe structures boast some of the oldest examples of existing buildings in the world. Buildings made with this construction technique offer considerable advantages in arid and dry climates: in fact, they remain cool during the day and warmer at night, as the adobe stores and releases heat very slowly.
Steps
Method 1 of 3: Preparation
Step 1. Set aside a space to work in and an area where the bricks can sit out to dry for some time (up to two weeks, possibly)
Step 2. Prepare a portion of soil that will be used to mix sand, clay and water
Mark the area with about 20 concrete blocks and arrange them so that they form a square, in two overlapping rows. Finally line the inside of the area with a strong tarpaulin.
Step 3. Do a "can test" to verify the suitability of your soil
Fill a jar (or clear plastic bottle) with a soil sample halfway through its capacity. Shake vigorously for about a minute, then let it sit overnight. In the morning, the soil should appear divided into different layers. The thickest aggregates - sand and small pebbles - will have deposited on the bottom of the container with smaller and smaller particles as you go up. The top layer will consist of clay or some other type of mud. Under ideal conditions, the three layers should have the same thickness. If your specimen has more than a third of sand (the bottom layer), you may not need to add any more sand to your adobe.
Step 4. Calculate the volume of your wall:
- Measure the length of the wall in meters;
- Determines the height of the wall in meters;
- Since the bricks (and therefore the wall) will be 25.5 cm thick, multiply the length by the thickness in meters (or 0.25 m);
- Multiply the result by the height of the wall. This will be the total volume of the wall in cubic meters.
Step 5. Retrieve the materials
- Sand (about 50% of your total volume). Sand is usually sold by the ton - you can calculate its weight by multiplying the volume by 0.5. The sand should be relatively fine - beach sand or a slightly thicker one works well. NOTE: The amount of sand you will need to mix depends a lot on the clay you have available, the climate and how strong you want the wall to be. This is all relative, and there is no "wrong" method.
- Clay (about one third of the total volume). Clay or potting soil is also usually sold by the ton. Multiply the volume by 0.9 if it's dry, by 0.7 if it's wet.
- Straw (about 10 - 20% of the total volume). Straw is sold in bales of various sizes. The most common and largest bales are 40cm x 50cm x 100cm, which equates to 0.2 cubic meters. Then multiply the volume by 0.15 to get the number of bales you need.
Step 6. Make a brick mold
A classic mold can be built using two wooden posts of 5x10cm size, which are 2.5m long. Consider that a common riser actually measures 3.8cm by 8.8cm, which is why the lengths are odd numbers.
Method 2 of 3: Create the Bricks
Step 1. Mix the sand and clay together in the area you have prepared
These should be mixed according to the quantities you have and the result you want to achieve (again, there is no method wrong).
Step 2. Add water
Add enough to make a thick mixture.
Step 3. Mix everything together
The easiest way to do this is to take off your shoes and socks and jump into them with both feet. Keep stirring until you find no more dry areas.
Step 4. Spread out a tarpaulin and start putting several shovelfuls of mud on it
As you shovel the mud out, try to let the excess water drain onto the soil you have prepared. You can also use a bucket to get the mud out and put it on the tarp.
Step 5. Sprinkle two large handfuls of straw over the mud
Your intent must be to break it up so it doesn't form lumps and to get rid of any harder sticks that could hurt you when you step on it.
Step 6. Crush the concoction
Jump for a long time: you will have to carefully mix the mud and straw.
Step 7. Lift one side of the tarp so that the mixture falls back on itself (as if you were kneading)
Step 8. Continue mixing the materials, adding straw as needed, until the mixture is solid enough and difficult to work with
Step 9. Take large handfuls of the mixture and place it into the brick mold
Make sure you press in the corners well, squeeze it to fill the mold and make the material compact.
Step 10. Let the bricks dry in the mold for a while (at least 15 minutes)
At this point you can remove them and fill the mold again.
Step 11. Let the bricks rest where they are and let them dry for about an hour
When they are firm and dry enough to move, turn them on their side to dry them a little more. It may take up to a week before they are dry enough to build the wall.
Method 3 of 3: Build the Wall
Step 1. Set up a gravel or stone foundation plane
Step 2. Lay the bricks flat on the foundation plane
Step 3. Use the mud mixture (or a mud and straw mixture) as a mortar for the bricks
You can spread layers of mortar up to 10 cm thick, however, as long as they are 2.5-5 cm thick.
Step 4. Use the mud mixture as plaster once the wall is completed and dry
This mixture should be drier than the one you used to make the bricks and will add a grouted effect to the wall, which will be very pleasing to the eye.
Advice
- Clay is a discrete soil with a minimal percentage of organic material and which has a lot of grip. It should be free of foreign objects such as twigs, rocks, shrubs, etc.
- Since the bricks are only 5cm high (like the posts), you will need 12 or more rows to make a 1.80m high wall.
- Cover the top of the wall with slabs of slate or other types of stone to prevent water from seeping into the masonry. This will extend the life of your wall.
