Raw brick (another name for this building material is adobe) is an excellent building material. It has long been known to mankind, is simple and convenient to manufacture and use. Saman is more common in southern places, but is sometimes found in the middle lane.
A trip to history
The first buildings where raw brick was used appeared almost six thousand years ago. This is not surprising, since a person needs somewhere to live, and funds for the construction of housing are often not enough. And it has always been like this: now, a hundred years ago, a thousand … If we are talking about living near the mountains or in a forest area, then cheap building materials are available in sufficient quantities. But what about those who live in the steppes or deserts? There, stone and wood were very expensive and not available to everyone. Of course, houses were built from expensive building materials there, but not everyone could afford such a luxury. And around the fourth millennium BC, a way was found to build clay buildings mixed with straw.
Properties of adobe,pros and cons
Raw brick with chopped straw is a very convenient building material. Its advantages include extremely low cost. After all, the cost of its production is practically zero, since the raw materials are literally underfoot. Another advantage of using this building material is its sound and heat insulation characteristics. Also, adobe is hygroscopic, due to which it has a beneficial effect on the microclimate in the room, absorbing excess moisture and preventing the occurrence of dampness and mold inside. Also, raw brick, like any building material based on clay, is fire resistant and provides significant fire safety for the building.
But this building material has several drawbacks. Raw brick walls are afraid of moisture, so a good layer of high-quality plaster is required to protect them. In a temperate climate, the brick dries for a long time and slowly gains strength. Also, adobe is unsuitable for construction in winter. Even in the walls of raw brick, rodents and other pests often like to settle. This can be prevented in advance by applying special additives or by properly treating the surface. Among other things, a building made of this brick is being built a little longer, since the walls need more time to reach the required strength.
Raw brick and its types
Saman is of two types: light and heavy. For the construction of light adobe, brick as such is not needed at all. A mixture of clay andfiller, and the filler is taken proportionally more than clay, and superimposed on the wooden frame of the building with the crate. Sometimes adobe is simply laid between the inner and outer wall sheathing. The advantages of this method are simplicity and speed. Disadvantages - requires a lot of wood. Heavy adobe - this is the same raw brick with straw. Houses from it are obtained much stronger, more reliable, built from ready-made blocks. Wall decoration is possible immediately after construction is completed.
Material selection
The firing of raw bricks is not done, therefore, in order for it to turn out to be of high quality, and the structure to be strong and reliable, it is necessary at the initial stage to pay all attention to the choice of material, that is, clay. A brick made of low-plastic clay will turn out to be brittle, and a brick made of very oily clay will crack due to changes in temperature and humidity. There are many ways to determine its quality. Let's look at a few of them.
The first method - stir the clay to the required viscosity, make three small cubes from it with sides of 20 cm each. The first cube should only be made of clay. In the second, you need to add about 10% sand. And in the last cube you need to add fatty clay, also in a proportion of 10-15%. On all the cubes on one side with a stick or a nail crosswise diagonally we make shallow lines. Their width is approximately 5 mm, and their length is 10 cm. The cubes are dried for a week and a half, and then the lines are measured. That clay, where the lines have become shorter by 6-10 mm (compressibility 6-10%), is optimal for makingadobe brick.
Second method - knead the clay well, form a ball about five cm in diameter from it and gently squeeze it with two even planks. Clay of low plasticity begins to crack when the ball is compressed by a fifth or a quarter of its diameter. Medium ductility - cracks appear when compressed by a third of the diameter of the ball. High ductility - cracks when compressed to half the diameter. Optimum plasticity is medium. We bring to the required plasticity with sand or oily clay.
The third method - a roller about 20 cm long and 1-1.5 cm thick is formed from well-kneaded clay. The roller is wound around a tube with a diameter of 20 cm. the most suitable clay composition, a network of small cracks is formed.
Clay preparation
The best option would be to prepare the clay ahead of time. Fold it into stepped ridges with a width at the bottom of up to two and a half meters and a height of up to a meter. Pour water over each stepped layer and let the material stand for one winter. But you can use clay without preparation. You need to knead such an amount of clay that there is enough work for one day. For calculation: to make 1000 pieces of standard raw brick, almost 3 cubic meters of clay are needed. It is scattered in layers of 15-20 cm, crushed and mixed with greasy clay or sand and with the filler that is chosen, that is, with chopped straw, chaff, chaff, etc. This should be done gradually and only in a dry state. Along the edges of the working platform, clay bumpers are made forwater retention. After that, they begin to pour the mixture with water. Usually there is water about 20-25% of the amount of clay. Clay is mixed to a homogeneous mixture with shovels, feet, or concrete mixers.
Making brick blocks
As a rule, the sizes of adobe blocks are of three types and depend on the climate of the area where the house is being built. The drier and hotter the climate, the larger the blocks are made, as they can dry well and gain the necessary strength. Small blocks have dimensions of 30x14x10 cm. Medium - 30x17x13 cm. Large - 40x19x13 cm. Do not forget that during the drying process, bricks lose up to 10-15% of their volume. Therefore, the form is made 5-6 cm larger than the future brick. Forms can be made on one, two or four bricks. You can do it without a bottom, or with a bottom in the form of boxes with handles. For better separation of the finished product from the mold, its walls can be upholstered from the inside with dense polyethylene. Brick blocks are made at the same place where they will be dried in the future. If necessary, the clay mixture is brought on a trolley, put with a shovel into molds with a top, rammed with a board, the excess is carefully cut off, and the blocks are laid out to dry.
Drying finished products
The finished adobe-brick is pierced in 2-3 places with a thin (1.5-2 mm) wire and kept on the molding site for three days. Periodically it is turned over for uniform drying. After this period, the blocks are placed on edge and dried for another 3-5 days. And only thenbricks are stacked in piles with a small gap between them. From above, the blocks are covered with mats, shields, tarpaulin, polyethylene, etc. The main thing is to prevent moisture from entering during drying. The drying process proceeds depending on weather conditions from 2 weeks to a month. The degree of readiness can be determined by looking at the fracture. The entire surface of the fracture should be uniform, without spots in the middle. Also, a brick thrown from a height of two meters must remain intact and placed in water for 48 hours must not lose its shape.
Building a house from adobe
As has been repeatedly mentioned, when building from raw bricks, special attention should be paid to the insulation of walls from moisture.
The foundation for adobe blocks is preferable to the tape type, 20-25 centimeters wider than the masonry itself. This is done to protect the walls from rain splashes. The height of the foundation is 50 cm and above. Material - rubble stone or concrete. A layer of waterproofing is required over the foundation.
Walls are usually built: external - from 50 cm thick, internal - 30-40 cm. The solution is made from water, one part clay and one part sand. Also, masonry can be reinforced with reeds, brushwood or straw. Do not lay in the rain. You need to immediately cover the walls and wait for dry weather. You can't build walls in winter. Immediately after the erection of the walls, their finishing with plaster is necessary. It is better to take gypsum plaster, since cement plaster does not have good enough adhesion to raw brick.
The roof is made light to relieve pressureon the walls, and with a large overhang up to 70-80 cm to move the drain away from the walls. The floor can be insulated with expanded clay, and on top it can be made of plank on logs.
Conclusion
That's all the main points that relate to the manufacture of raw bricks and what you should pay attention to when building a house from it. The opinion that such a building is short-lived is deeply erroneous. A house made of adobe, built in compliance with all technologies, will stand for more than one hundred years. These houses are warm in winter and cool in summer. No wonder interest in adobe houses is returning all over the world.
