Building Our Earthen Home Episode 6 Soil Selection

Most of the soil in the world can be used to build houses. The main components of the soil that we want to use to build a house is clay and sand. If it's too high clay, the house can crack, the bricks can crack a lot. But if it's too high sand, it will not attach together, it will not stick together. So we need the good ratio of clay and sand. The sand, the clay, is very special character because when it dries, it's very hard, it's very hard to dig. And then when it's wet, it expands a lot. If the soil has very high clay, when we dig it, we can see where our hole cut it. It will be very shiny, very smooth like this. And then, if you look at the soil in the ground, when it's dry, you can see the big crack on the ground everywhere. Sometimes this crack can be very deep. This is the character of clay, so we can see clay easily. And everywhere we go, we just look at the soil. When we see cracks, that means there's clay. That means we can use the soil in that area to build a house. So a house can be built with clay from everywhere in the world. There is only one kind of soil that is not good to use to build a house, that is silt. Silt mainly is very red color. It looks like clay, very fine, very smooth. But when we make bricks, and then if we drop it, it cracks, it crumbles like this. There are many ways to test the soil. The first technique that we can test the soil, we use salt, glass, water, and soil that we want to test. This is the more academic way of testing. So the soil that we want to test, it's good to smash it to make it very fine. It can be dissolved in the water easily. And then we get a glass, and clear glass is important, because we can see it very easily. And add water in the glass, but not very full, because we need to add many things in that water. So we just add one tablespoon of salt. It can be any kind of salt. It doesn't need to be Himalayan salt or black salt. Any kind of salt is fine. And then add the soil that we want to test in that glass. We can use very fine one, it can be dissolved easily. And then when we add the soil, we need to stir it very well, make it completely dissolve in the salt water. And then we just let it sit. After we stir it very well, we let it sit for a while. Normally, when we add salt, it will settle very fast. Normally, it will take less than one minute. It will settle like this. But if we have no salt, it maybe take longer time than that. So when it's set like this, we can see it's quite clear what is in that soil. If we have anything in the soil, we can see very clear. The bottom part of it, it will be the heavy thing like rocks. And then higher than rock, it will be rough sand. Higher than rough sand, it will be fine sand. And above fine sand will be clay. And above clay will be silt or dust. So we can see it clearly. What kind of soil do we have? What is the component of our soil? It's very important to know this before we build our own house. Clay is very fine. It's on top of fine sand. Normally, because it's very light, so it will settle later than sand. What we need is clay at least 5%, but not more than 40%. And we don't want silt. That's the main thing. The second technique is making mud noodles. To test this technique, it's very simple. Normally, I use this technique a lot in my life because I just need water and soil or clay in that area. That's all. Add water in the soil and knead it like we are going to make pottery or to do some kind of sculpture or whatever. So make it into a small noodle like this and then hold one end of it. If it breaks and comes off easily, that means too much sand. It's not good to use. If we want to use, we want to get more clay to mix with that sand. But if it stays, that means it works very well. This is a very simple, easy way to test. The third way to test the soil is what we call muddy hands. Just put our muddy hands in the water. If it comes out without cleaning, if it comes out clean, that means there's too much sand. If we want to use the soil, we need to add more clay. But if the soil sticks in our hands, that means it's good. But if we wash our hands more than 10 times, it's not clean yet. That means too much clay. If we want to use that soil, we need to add more sand. At least two to three times of sand. That it will work okay. So it's so simple and easy to test the soil. And then we can use the soil almost everywhere in the world to build our house. If it's too high sand, just add a little bit of clay. If it's too high clay, just add at least two times of sand in that clay. We can use to build a house. That is very easy.