In this Article: A History of Thatched House Building; thatched houses over 80 years old; straw block - characteristics; selection of straw and straw blocks for building a house; how to build a house from straw - stages of work; thatched house and the necessary tools; plaster for straw walls; build a house from straw - take fire prevention measures.
- DIY straw house
- At the end
Straw as a building material - history
Straw has been used as a building material since ancient times - the African population has been building houses from it for thousands of years, thatched roofs and thatched attic insulation were very popular in Europe, Russia and Ukraine back in the 19th century. More than 150 years ago, a new technology for the construction of thatched houses appeared - a wooden frame, a plank roof and walls filled with blocks of compressed straw. The European settlers, actively exploring the territory of North America, faced a shortage of timber in the plains of Nebraska and were faced with the need to live in turf-covered dugouts. The settlers who founded the town of Sandhills were especially unlucky - the local soil was so scarce that it was impossible to remove sod from them without serious consequences for livestock breeding. Local farmers found another way out and began to build frameless houses from straw pressed into bales, coating the walls with clay-lime mortar with chaff mixed in it. The increased need for straw blocks led to the invention of mechanical stationary presses in 1850 and mobile straw balers moved across the field by horses in 1872, and steam-powered balers a few years later.
In 1925, in France, panels were invented, formed by stacked parallel to each other straw stalks, tied with wire and covered with cement-clay plaster on top. This wall material never gained popularity in Europe, however, in the period from 1936 to 1949, several houses of straw-cement panels were nevertheless built, but only in Australia - local industrialists tried to save on building materials due to the continent's remoteness from the rest of the civilized world. and the country practically did not have its own resources. A remarkable fact - several Australian houses, built from plastered straw panels in the middle of the last century, have been perfectly preserved to this day. By the way, in the late 90s, during the demolition of one such house in the town of Altona, the workers suddenly encountered difficulties - they could not manually dismantle the walls, they had to call in special equipment. In the 80s, straw housing became popular again, mainly due to the unique combination of heat-retaining, strength and environmental characteristics of straw blocks. More than 110,000 straw houses have been built in Europe, the USA, Australia and China in 30 years. Since the mid-90s, several thatched houses have been built in Russia, Ukraine and Belarus. Straw block characteristics
By and large, straw is a by-product and low-value agricultural product - it can be fed to livestock only after heat treatment and the introduction of additives that increase nutritional characteristics, the roof has not been closed for a long time, but it is only suitable for mulching the soil. Considering that cereal crops are grown on the territory of Russia almost everywhere, there is no shortage of this building material - the construction of walls for a house with an area of 70 m2 will require straw remaining after the harvest of cereals from 2-4 hectares. Meanwhile, most of the straw that remains after harvest is usually burned. What is a straw block? It is a tightly compressed bale that has a rectangular shape and consists of dried stalks of cereals, from which the grain has been completely extracted. The overall dimensions of straw blocks can be different, the following are most suitable for construction: width 500 mm; height 400 mm; length 500–1200 mm. The weight of a half-meter block with a density of 120 kg / m3 is about 22-23 kg.
Flammability of straw. Indeed, dry stems of any plant burn perfectly, however, when pressed, it is rather difficult to set them on fire due to the low air content inside such a block. For example, one by one sheets of paper also burn well, but if you try to set fire to a folded pack of such sheets, you will only be able to charcoal them around the edges - the same thing happens with a compressed straw block, despite the high flammability category G4. Since the wall, assembled from straw bales, is completely covered with clay or clay-cement plaster with a thickness of at least 30 mm, the threat of its fire is much lower than that of the walls of a wooden blockhouse. Low price and availability of material. Blocks can be formed from wheat straw, rye, flax, rice, as well as hay. The cost of a straw block is ten times lower than that of a brick. Low thermal conductivity - 0.050–0.065. Straw conducts heat worse than wood (0.09–0.18) and brick (0.56–0.70). The thermal conductivity of the compressed straw is further reduced if the blocks are formed only from longitudinally oriented stems in relation to the future wall. The energy consumption of a thatched house is about 40 kWh / m2 per year, not particularly increasing even in the low temperatures of the Russian climate. Reducing construction time and scope of work. The assembly of walls from straw blocks is done quickly, without any masonry mortar, does not require the involvement of specialists and construction equipment. A lightweight foundation, usually columnar, is sufficient for a thatched house. 
Finally, it is impossible to dispute the ecological characteristics of straw, a natural material that is not treated with chemicals during the construction process, since there is no particular need for this. Disadvantages of straw walls - insects and mice can start in them; when the humidity of the straw rises above 18–20%, putrefactive processes begin in it, destroying the straw blocks. Both problems can be solved simultaneously by pressing blocks to a density of 250-300 kg / m3 - given the thick layer of plaster, it is extremely difficult for rodents and insects to penetrate into such a dense wall, and as the density increases, a block of straw will absorb moisture worse. It should be noted that an increase in the density of blocks will lead to an increase in their weight two to three times, which will create some difficulties when building a wall. To combat insects, it is necessary to sprinkle them with slaked lime when laying blocks and use lime when drawing up a plaster mixture. DIY straw house
House wall rails are made of straw bales formed by a baler and tied with a polypropylene cord - you need to choose them carefully. Strapping made of natural fiber or steel wire, sometimes used to create bales in agriculture, is not suitable for construction purposes - the wire rusts, and natural fibers are fragile and prone to decay. In some agricultural enterprises, straw is collected with round balers, straw rolls, in principle, can be rolled out and squeezed with a bale baler, but it is better not to do this - the straw will be badly bend, which will affect its thermophysical characteristics.
What is the best straw? Rye or rice, and winter rye straw is most suitable, because its stem is denser, taller and, moreover, winter rye is harvested earlier than other crops. To build a house, only dry, seed-free and not chopped straw is required - you should not form bales of wet straw, you must first dry it. How to evaluate the performance of a straw block? A dry bale with a length of no more than a meter and a density of no more than 120 kg / m3 can be lifted by hand - it is not particularly heavy. To check the moisture inside it, you need to stick your fingers inside, then take it out and bring it to your nose - when immersed in the straw, your fingers should not feel moisture, when they are brought to your face, there should be no smell of rot. Remove a few straws from the bale and bend them - brittle stems mean old and stale straw and won't work for building. Qualitatively compressed bales practically do not deform if they are lifted by the strapping, it is difficult to put two fingers under the strapping cord, the blocks have similar dimensions. Like any other building, a thatched house needs a foundation, albeit a lightweight one. Its type is determined depending on the characteristics of the soil at the construction site. To ensure thermal insulation of the foundation and reduce energy losses of the building in the future, you will need expanded polystyrene sheets with a thickness of 100 mm or more - they are laid on the outside of the foundation and buried in the ground below the depth of its freezing. 
It is important that the floor level in the house is lower than the position of the first row of straw bales - in the event of water leaks, the walls with straw filling are guaranteed not to get wet. Next, we decide on the type of construction of the house - you can build a building with and without a frame. In a frameless house, walls made of straw blocks perform a load-bearing function, so it is more convenient to use bales with a density of at least 200 kg / m3. In addition, a frameless thatched house can only be one-story, with walls no more than 8 meters long, and the area of openings for windows and doors should be less than 50% of the area of the wall in which they are made. A house with thatched load-bearing walls needs a lightweight roof structure - a four-pitched roof structure will be optimal, the rafters of which are exposed on a wooden Mauerlat made of two boards laid on top of the wall and interconnected by cross members in one meter increments. Roofing material is laid on the pre-plastered end of the wall before installing the Mauerlat. The overhang of the roof cornice behind the wall is more than 600 mm. The advantage of a frameless straw house is its low cost and ease of construction. 
A wooden or metal frame for a two-story house or a house with a large area from straw is created in the same way as the frame of panel houses. You can build a double-row frame and stack hay bales between two support posts. Filling the wall sections between the frame posts with straw blocks is easier than removing frameless walls - we will focus on them, especially since the sequence of operations is largely the same. 
During the construction of a frameless or frame house, the ligation between the blocks is carried out with wooden stakes or metal rods (diameter 40-60 mm), driven vertically into bales of straw arranged one below the other, stacked in a staggered manner (without matching seams), the higher the rows of the wall are raised , the longer the stakes are needed. The bales are fastened to each other after the fourth row has been laid. Also, metal rods are embedded in the basement of the building with a step of 1000 mm - their length must be sufficient to pierce the blocks of the first and second row. In frame construction, bales of straw are tied to the supporting pillars using horizontal metal pins, and the pins that fix the blocks in their places can be walled up in the foundation and brought out under the Mauerlat by stringing compressed straw on them and clamping the Mauerlat beam using a threaded connection. Neighboring walls during frameless construction are connected row to row by two 30 mm diameter pins curved in a U-shape. It is necessary to perform such fastening both along the outer and inner line of the walls' mating - at least two curved pins in each row. 
Before starting work on the construction of straw walls, you will need to make two simple devices: a press for crimping and bandaging blocks before cutting; several pointed metal hooks for transporting straw bales. The press consists of a pillar about a meter high, dug into the ground and reliably fixed, on which a wooden beam-lever is movably fixed. At the end of the lever, small grooves are cut out, in which a nylon rope is fixed in the form of a loop. The straw block to be trimmed is placed under this makeshift press, clamped with a looped leg and tied with a plastic cord to a new location. Walls are assembled with hay blocks from the location of the openings and from the corners to the center of the wall. Under the bales of the first row, you need to lay a fine-mesh polymer net as an additional protection against rodent penetration into the walls; Kraft paper or cardboard is laid between blocks with a density of less than 200 kg / m3 during the formation of each tier - it will interfere with convective heat exchange inside the wall. In the process of laying rows into a frameless house, you do not need to drive the blocks into their places with considerable effort - the wooden guide-stops, previously set along the edges of the walls, can move. Align blocks in rows according to the level of twine stretched between the guides, using a board of sufficient size and a heavy hammer. The walls brought out under the roofing structure should not only be secured with hammered pins, but also tightened with plastic tapes in one meter increments - wrapped below a metal pin protruding from the foundation, tied and pulled around a wooden Mauerlat at the end of the wall. A metal tape for tying walls will not work, because cuts hands and is quite tough - difficult to pull. 
Vertical and horizontal boards are placed in the openings for doors and windows, forming a box, fixed with temporary wooden crossbars nailed to the boards. The lower and upper boards of the box are brought out of its borders - up to half of the adjacent straw blocks. Upon the construction of the wall, the boards of window and door openings are fixed with pins in bales - pins are driven into vertical boards inside the opening, horizontal boards located above and below the opening are attached outside it. Before fastening the opening box, it is necessary to overlap a roofing material or roofing felt under the boards, lay a plastic or metal mesh of reinforcement over it with an extension of 300 mm beyond the edges of the opening and fix it with 35 mm galvanized nails or 35 mm construction brackets using a stapler. Reinforcement will strengthen the straw blocks and prevent the formation of gaps between the wall and the opening box. If the blocks have a density below 200 kg / m3, then nails and staples will not hold in them - in this case, the reinforcing mesh is fastened with nylon thread or steel knitting wire pierced through the straw. To sew a straw block with thread, you need a homemade needle - a 10 mm metal rod, flattened and sharpened on one side, bent into an L-shaped handle on the other. A hole is drilled in the flattened end - a thread or wire is threaded into it, like a regular sewing needle. 
After assembling the walls, you need to trim them in those areas where the blocks protrude especially - for this operation and for cutting the blocks during installation, you will need a chainsaw. Before the next stage - applying plaster - wire communications are inserted into the wall in a cable channel made of self-extinguishing polyvinyl chloride. Plumbing, heating and sewerage pipes are not placed in the straw wall, because cause moisture condensation and rotting. The final stage of work on the creation of thatched walls is the application of two layers of plaster. Nuance - if blocks with a density of 200 kg / m3 and higher were used, then plastering can be done immediately after the walls are erected. In the case of less dense blocks, it is necessary to wait two to three weeks for the straw to settle and self-compact. Cement plaster cannot be used, it will prevent the passage of air saturated with vapors through the wall, in other words, it will prevent the wall from "breathing". Suitable mortars of plaster on a clay-lime and cement-lime base, having an average fat content. 
Proportions of clay-lime mortar: clay dough (clay mixed in water) - 1 part; lime dough - 0.4 parts; fine-grained sand - 3-4 parts. Proportions of cement-lime mortar: cement - 1 part; fine-grained sand - 3-4 parts; milk of lime (dough of lime mixed with water to a milk consistency). The sifted cement and sand are mixed dry, then milk of lime is added to the container with the mixture until the mixture of the required consistency is obtained. To reinforce a straw wall from its outer and inner sides, you will need a metal or plastic mesh, with a cell of no more than 30 mm. The first layer of plaster should be thick - about 25–40 mm, leveling the second layer - 2–3 mm, it should be done with a creamy plaster mortar. After the plaster is dry, the walls can be painted with water-dispersible paints - oil paints will not work, because act as a barrier in the air exchange of the walls. Thatched walls must be plastered - trying to avoid this by covering the straw bales with drywall, plastic or brick will create optimal conditions for rodents and insects, because there will be enough space between the straw wall and the cladding for their life. In addition, panel and brick cladding of unplastered walls increases their flammability due to the same gaps. And one more thing - you should not use the vapor barrier of straw walls, this will lead to rotting of the straw. 
Important: in the process of construction work on the construction of a thatched house, it is imperative to observe the following fire safety rules! During the installation of the walls, until they are completely covered with plaster and the perimeter is completely cleaned of scattered straw, smoking, welding and other types of work with heating to high temperatures, using an open flame and accompanied by sparks are strictly prohibited on the construction site. Uncompressed straw is highly flammable, and the slightest spark is enough for it to ignite - you can't joke with it! During the construction of a thatched house, the construction site must be equipped with fire extinguishing means - barrels of water, loaded and serviceable fire extinguishers, hooks. If a fire does occur, you need to quickly scatter the walls with hooks and fill the smoldering blocks with water. new straw blocks will cost significantly less than a new frame. At the end
Straw housing undoubtedly has great prospects - in conjunction with eco-house technologies, cheap, using a minimum amount of thermal energy in the cold season and independently air-conditioning straw houses can give their owners more than just environmentally friendly housing. Abdyuzhanov Rustam, rmnt.ruUnlike manufacturers of modern finishing mixtures, clay plaster is really an environmentally friendly building material. It has indisputable advantages, and its technical and operational characteristics are quite sufficient for solving most problems in construction.
This, and the types of compositions, and the correct technology for applying with your own hands will be discussed in this article.
Advantages and disadvantages
Most often, such plaster is used for finishing adobe (adobe) and wooden walls. There are certain advantages and disadvantages of clay plastering of a log house, a log house or a structure made of rounded logs.
Plastering wooden walls inside the house with clay, photo of a living room with a fireplace
Advantages:
- Cheapness of material;
- Absolute safety for the environment and for humans;
- The ability to quickly and safely dispose of or reuse;
- A vapor-permeable material capable of regulating indoor humidity;
- Non-flammable, when heated to critical temperatures does not emit carcinogenic or toxic substances.
Flaws:
- Requires experience and accuracy in finishing;
- Sensitive to moisture;
- Reinforcement of walls with metal mesh or shingles is necessary.
Traditional and modern formulations
One of the oldest recipes for making a clay mortar for plastering walls has the following proportions:
- Clay 10 parts;
- Sand 5-8 parts;
- Straw 5-10 handfuls.
Such a wide spread of sand occurs because the clay in different regions has a different fat content. The fatter the clay, the better its plasticity and the higher the adhesive ability. Determining the fat content of clay for plastering walls is simple. A small lump is soaked in water and a ball with a diameter of 50 cm is molded from it. The material should knead well, but not stick to your hands. Then the ball is squeezed in the middle, if it has turned into a neat pancake, then such a material is greasy and suitable for plastering with clay, and if it cracks at the edges, then such material is skinny and unsuitable for wall decoration.
Refractory composition
There are numerous ready-made refractory compounds on the market with the addition of lime, gypsum or cement binder. However, for plastering furnaces, it is enough to use fireclay clay, and fiberglass as reinforcement. Previously, asbestos fiber was used, but it is too harmful to humans.
Furnace finishing with clay plaster, composition with fireclay clay
Moisture resistant formulations
Clay plaster with the addition of a small amount of cement, in a ratio of 1 part of cement to 7 parts of a clay-sand mixture, obtains a fairly high resistance to moisture. at the same time, it can absorb up to 60% moisture from the atmosphere, which has a positive effect on the microclimate of the bathroom.
Bathroom decoration
Insulating compounds
The traditional material for insulating plaster, horse dung, is now quite scarce, therefore, plastering a wooden house inside with clay for insulation is made with a composition with sawdust, which is mixed into a standard mixture, but without adding straw. Plastering of a wooden house with clay and sawdust is carried out exclusively indoors.
Plastering
The main way to avoid cracks when plastering with clay mortar is to use metal wire reinforcement or to shingle the walls. In addition, the ratio of ingredients is slightly changed towards reinforcing substances of natural or artificial origin. More straw and less sand are added. Such a ball of plaster is intermediate, since it does not have a very neat appearance.
A solution with a lot of straw to avoid cracks
Video of the process of plastering the clay walls of a house made of adobe (adobe):
3.2 Straw and plaster are the perfect combination. Interior and exterior decoration
Why straw, and not mineral wool, ecowool, expanded polystyrene, polinor, holofiber, fluxan or any other type of insulation?- frequently asked question. In comparison with other heaters, straw has one "drawback" - it needs to be plastered. In quotes, because it depends on how you look at it. Let's get a look.
Plaster is considered a disadvantage by those who want to save money on the construction of a frame house, replacing the mineral wool with cheap straw. Why plaster, if you can also sew up the walls of the centralized industrial complex or smallpox and enjoy the "saved" time and money? Usually this is done by unscrupulous "eco-builders" who either do not understand the role of plaster, or are deliberately deceiving themselves and their customers. Our tip: If you don't want to plaster, don't mess with the straw! it is better not to do it at all than to do it badly.
For us, plaster is an indisputable advantage and superiority of straw over other heaters!
We will not now consider the types and compositions of plaster, methods of applying it, etc. Let's talk only about its properties and role in conjunction with straw.
Outer plaster layer - 2-3cm
Winter assembly and plastering at home
in the Moscow region
This layer has many functions:
1. Wind protection.
Insulation (any) will not work without high-quality wind protection. The task of any insulation is to delay the movement of air inside itself, to delay convection, heat transfer. If there is no windscreen, the wind will walk inside the insulation and blow warm air out of it. When there is no wind, the straw will keep warm, in windy weather it will not.
2. Fire protection.
This is the main advantage of straw - it can be plastered to create a fire retardant shell for your home. Exterior plaster covers the entire house, protecting not only the straw, but also the frame from the effects of fire. Not a single skeleton frame can boast of this, especially a domed one. After all, it does not matter how non-combustible the insulation itself is, if the wooden elements of the frame are not protected, the whole house is not protected. Lime plaster is also an excellent wood treatment, the frame under such protection will last much longer without any chemical treatments.
Outer plaster layer
3. Protection from rodents, insects.
There is a widespread fear that living creatures will settle in the straw. Yes, he will definitely live, if you do not plaster the wall. Plaster does not create a space between itself and the straw, like sheathing with CPB or other material. In the straw itself, mice do not live because of the high density (this is a fact), but in the space between the skin and the straw - they feel great and will definitely settle, whether it be rye or wheat straw - no difference. Only plaster protects the walls from living creatures: mice, flies, ants, spiders, etc., which, by the way, willingly live and reproduce in the mineral wool, just in straw, as they say - God himself ordered))) nature is drawn to nature .. ...
Internal plaster layer - 5-7cm
This layer has the following functions:
1. Protection from fire and rodents - similar to external plaster.
2. Vapor barrier (conditional).
A thick plaster layer does not allow moisture to pass into the insulation, as a result, the straw always remains in a dry state, natural moisture, and condensation does not form at the "dew point". The straw does not get wet, does not reduce its thermal properties, does not rot, and mold does not start. In addition, clay or lime plaster protects the wooden elements of the frame, prolonging the life of the house.
An example of artistic interior decoration
clay plaster
4. Finishing. The standard finishing of all domed frame frames is clapboard or painted smallpox. Plaster creates coziness, gives free rein to imagination, uniqueness of the interior. This is no longer a building, This is a HOUSE! Home for Life!
We try to write our articles in a free style, in an accessible, understandable language, so we get a lot of scribbling, not everyone can master. And yet, we are writing for those who want to understand the issue and make the right informed choice in favor of a domed house made of thatched panels. We sincerely believe this is the perfect option!
A thatched dome for lucid people!
Clay plaster, the composition of which is simple and literally lies under our feet, is increasingly found on construction sites as a facing material for interior and exterior decoration. It is known that it was the main material for the masters many centuries ago, why do we return to this experience again today?
Plastering walls with clay - what is this process?
The return to the ancient traditions of construction is no coincidence. Modern mixtures for decorating houses practically do not exist without chemicals, which, over time, harm the body. The cheaper the composition, the more harmful. Expensive plasters are not available to everyone, and they do not become less chemical. Clay interested the consumer primarily in its ecological purity, because the ancient craftsmen did not have a chemical industry.
And even not such old village buildings, where this material was used, are still functioning properly, which means that the clay does not crumble in a couple of years, but behaves like a full-fledged durable natural finish, not only not harmful, but even useful for humans. Plastering walls with clay is cheap, and for those who are especially thrifty there is an opportunity not to spend a penny on components, but to dig them out on their own from the nearest quarry, river, or even on their site. After all the mixture requires only clay and fine sand... But this is an activity for extreme lovers, because the depth of good clay is about 1.5 m, and it will not take so little.
Even if you buy ready-made mixes, they are quite cheap. Only when choosing, you should pay attention to the place of extraction, because clay is a good adsorbent of harmful and sometimes radioactive contamination. There are no problems with the color of the plaster, because natural clay can be of several shades, roughly representing the entire palette from reddish-red to blue, and it depends on the location and depth of extraction. Colorants, although natural, are rarely added, and natural fillers such as straw can be used for texturing.
Clay plaster - composition and properties
In addition to being cheap and environmentally friendly, this one has a number of other advantages. Therefore, before instructing how to plaster with clay, consider what we win and what we lose. The layer that you get on your walls will not decay very soon, which will be indicated by numerous cracks, because clay is very elastic, and gives this quality to the plaster mixture. Her appearance will always be presentable and original, as a natural material, she is not afraid of humidity, temperature jumps, wind and even moderate earthquakes. Its density creates the effect of preserving the room, not letting in harmful substances, for example, exhaust from the street, it is believed that even electromagnetic radiation is to some extent blocked by such walls.
After a dozen years, the first crack may appear, but the restoration is done almost instantly, and it is unlikely that the entire wall will need to be covered; it is enough to fake the problem area. A layer of clay plaster breathes well, allows moisture and steam to pass through, the microclimate in the room will be almost ideal from all possible options. And there is no need to wait for unwanted guests in the house, various kinds of insects simply cannot gnaw through the strong bonds of natural clay. The advantages can be attributed to the hypoallergenicity of this material, as well as the purity of not only the layer on the walls, but also the construction process itself. No harmful waste is generated, because everything is taken from nature, and it is not shameful for her to return the surplus.
It would be unfair not to indicate some of the difficulties that will have to be faced. If you are doing it for the first time, then you will have to feel all the capriciousness of clay plaster, because it is not so easy to prepare it, because there is no recipe, readiness is assessed by a practical method. We will try to help you master it, but if you have an experienced master, it is better to take him to help. By the way, finding such a person is also not easy, because clay is not yet so popular, and previously it was not taken into account at all, few people know how to really work with it competently. The plastering process itself is quite lengthy, you will have to wait a long time for each layer to dry, and if you do external finishing with this material, then restoration will be required almost every year. Although the plaster will not crumble, it will crack often.
How to plaster with clay - work sequence
Let's start describing the work itself, because there are many nuances here, so we will no longer be distracted by theory.
How to plaster with clay - step by step scheme
Step 1: Preparing the base
Clay plaster is heavy, so the adhesion must be very high. To do this, it is desirable to have tangible roughness on the wall, and it is better to build a shingle (wooden lattice). If the walls are brick, then clean the surface of any remnants of the previous finish and slightly open the seams. Then the clay will lay down confidently and for a long time. A wooden house should definitely have shingles; making notches on logs is a thankless task. Do not use metal, since the clay is unlikely to be able to squeeze into it with high quality, it is too dense.
Step 2: preparing the mixture
A clean mixture of clay and sand is used for the finishing plaster, as it is very "cold". The clay must first be soaked in water for 2-3 hours, then a little more water is added and mixed thoroughly to obtain a homogeneous mass. Then sand is poured into the container, the composition is mixed again. But the proportions need to be selected empirically, they will depend on the original fat content of the clay. This is checked in several ways, but the fastest and does not require a perfect eye is the ball method.
To begin with, achieve such a state that the mixture does not stick to your hands, this is done by gradually adding water. Then we take a little of the mixture and sculpt a 2 cm ball.You should put it on a hard surface and flatten it, just not to a thin pancake, but to an impressively plump one. Now pay attention to the edges, if cracks have formed on them, then the solution is non-plastic, more clay is required, if there are no cracks, then you guessed right with the proportions and you can start working. On average, 50-80% of sand is required for mortar.
The main plaster solution is prepared with additives, it can be sawdust, straw, needles. Such a solution holds more firmly, i.e. fillers give a reinforcing effect and keep warm better. The "warmest" is a purely clay solution with the same additives, but it is not plastic and will definitely require finishing, since the cracks will not take long to appear.
Step 3: applying plaster
The first layer is covered with sloppy lumps, and in order to better adhere them to the surface, you need to make some efforts, i.e. press down on clods, and not spank with a spatula, as is done with other plasters. If this layer is the only one, then it must be smoothed with a trowel ideally, if not, then it is enough just to roughly bring the surface to one level. It is necessary to let the layer dry, it will take a little more than a month in the summer, and in the winter all three.
Then the next layer is applied, usually "cold", see the description above. Its thickness is small. You can also use a grout, where cement is also added to the clay with sand. In this case, the ratio of clay-cement-sand is 1: 1: 3. The surface should now be flat. And this layer should dry, give it a few weeks. Do not try to speed up the process; forced drying will ruin the finish right away. Further, the wall can be decorated, painted or left in its natural color. If some kind of finishing is still conceived, then a number of additional preparatory work should be carried out, for example, a primer.
Some builders thatched walls are plastered without a reinforcing base. This is possible where "sticky" plaster with the addition of clay acts as a bonding mortar. With less sticky plaster (based on cement), metal mesh is usually used, especially in places prone to damage such as corners and around windows. (Fig. 1 ).
Reed nets or thin strips of wood (approximately 1x3cmx2m) nailed vertically or diagonally across each 3-4 cm to vertical (5x5cm) evenly spaced wooden strips ("shingles") can be used as ecological reinforcement for plaster. the strips are cut into the surface of the blocks (such grooves can be made with the sharp end of a hammer) and are firmly attached to the inner posts or the tops of each successive row of blocks (Fig. 2) are fastened using a "straw needle". Vertical corner guides are made in the same way.
Separation of walls and ceilings.
When filling the joints of walls and ceilings, use the wooden grid system described above or a metal mesh attached to the frame on both sides (Fig. 4). "loose straw" is gently packed into the spaces between the grates and then plastered.
Plastered ceilings have good fire resistance in attics insulated with thatched blocks; it is best to use a metal mesh in this situation, although you can do without it.
Plastering.
Plastering can be done by hand or with a plastering station. Straw walls allow most plastering techniques. Plastering can be done in different ways - spreading or scattering with different tools. Spreading is easy to do, but only applicable when using thick solutions. Sketching is much more difficult.
Plastering based on cement - the most famous, but not as easy to use as lime, gypsum and other clay-containing "mud" techniques.
For the manufacture of cement-based plaster, the following components are usually used:
One piece of Portland cement;
One part of slaked lime;
Eight parts of clean, sifted sand.
80% of pure ox from the total volume of all components is added to the container. Then sand and lime are poured. Everything is mixed for one minute. Then cement, water is added as needed. Stir again for 10 minutes to create a good, sticky mass.
The plaster is applied in 2-3 layers (in the final layer, the amount of sand is reduced to 6 parts). After the end of the work, the moisture of the cement plaster should be maintained for several days. This will increase its strength.
Clay-containing "mud" plaster is made from proven clay with a sufficient amount of sifted sand. To prevent cracking, this mixture is mixed with straw in a ratio of 3-5 parts of sand to one part of clay.