The foundation for a thatched house, although lightweight, will still have to be arranged. The type of foundation can be different, it is selected based on the properties of the soil on the site. To simplify the task of thermal insulation of the foundation, polystyrene foam 100 mm thick is laid along the outer side of the foundation, and the thermal insulation sheets are buried in the ground deeper than the soil freezing level. For a thatched house, it is important that the level of the "clean floor" in the house is below the base of the first row of thatched wall blocks. This will help in case of water leaks to prevent the walls from getting wet. You can learn more about choosing the type of foundation for a house from our article.
house frame
The design of the house can be both frame and frameless. In the case of a house without a frame, it is necessary to follow some rules: the blocks must have a density above 200 kg / m 3, you cannot build a house above one floor, the length of the walls should not be more than meters. In addition, the roof structure can only be lightweight. That is, frameless technology is possible, but imposes a number of significant limitations.
Another thing is a frame made of wood or metal. With such a frame, you can safely build a spacious two-story house, while the frame construction technology does not differ much from the frames of panel houses.
Most of all, for the construction of a straw house, a two-row frame is suitable. With this design, the blocks are stacked between two pillars that perform load-bearing functions.
When building straw walls, it is imperative to bandage the blocks; they are usually coupled with wooden poles or reinforcement (40-60 mm in diameter). The rods are driven in vertically, punching blocks lying on top of each other. Straw blocks must be laid in a checkerboard pattern so that there are no overlapping seams. The bales are stapled after the fourth row.
In addition, the reinforcement must be concreted into the foundation in increments of a meter; the first two rows of blocks are placed on the reinforcing bars. Adjacent walls should also be linked together, and this is done using U-shaped brackets 30 mm in diameter, two per row.
Collect walls from straw blocks starting from the corners or from openings to the center. To further protect the walls from mice and rats, a fine-mesh net is laid under the first row of bales. And when the walls are erected to a predetermined height, then the structure is strengthened by constriction with plastic tapes, one end of which is attached to the pin previously left in the foundation, then the tape is pulled around a wooden Mauerlat laid along the perimeter of the wall. You can read about other types of walls in the article "What are the walls of the house."
Openings for doors and windows are made as follows: the upper and lower boards of the box are brought out to about half the length of the blocks. Boards are attached after the walls are erected. A roofing material is laid under the boards, a reinforced mesh is laid on top, with a release along the edges of the opening up to 30 cm. The mesh is attached to the walls with a stapler or galvanized nails.
Plastering straw walls
After the walls are erected, you can start plastering, but before that you need to bring communications into the house, and only wires in a special cable channel. It is not worth laying pipes in straw walls - the process of condensation and, as a result, decay, is inevitable in this case. If the cables are wound up, then proceed to the plastering of the walls.
Straw walls are plastered in two layers, and if the block density is more than 200 kg / m 3, then work can be started immediately after construction, if less, it is necessary to give the straw time to settle and compact.
For plastering, cement-lime and clay-lime mortars are used. You will have to forget about cement plaster, because it does not allow the walls to "breathe", which is unacceptable for straw structures.
Cement-lime mortar is prepared as follows: one part of cement, 3-4 parts of fine-grained sand and milk of lime, which is added to the mixture until a solution of the desired consistency is obtained.
Clay-lime mortar is obtained by mixing one part of clay dough, 0.4 parts of lime dough and 3-4 parts of sand.
Before plastering, the walls are reinforced, both outside and inside, for this a steel or plastic mesh is used. The first layer of plaster is thick, 3-4 cm, it is a leveling layer. The second thin, 2-3 mm. After plastering, the walls are allowed to dry, after which you can start painting. The paint must be water-dispersed, oil paints in this case cannot be used for the same reason - they do not allow the walls to "breathe".
In this article: the history of straw 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; straw house and necessary tools; plaster for straw walls; build a house out of 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 population of Africa 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 wooden roof and walls filled with blocks of compressed straw. Actively developing the territory of North America, European settlers faced a shortage of timber in the flat territories of Nebraska and faced the need to live in dugouts covered with turf. The settlers who founded the town of Sandhills were especially unlucky - the local soils turned out to be so poor that it was impossible to remove sod from them without serious consequences for cattle breeding. Local farmers found another way out and began to build frameless houses from straw pressed into bales, coating the created walls with a clay-lime mortar with floor (chaff) mixed in it. The increased demand for straw bales led to the invention of mechanical stationary balers in 1850 and movable straw balers moved across the field by horses in 1872, and steam-powered balers a few years later.
In 1925, panels were invented in France, formed by straw stalks laid parallel to each other, 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 from straw-cement panels were still built, but only in Australia - local industrialists tried to save on building materials due to the remoteness of the continent from the rest of the civilized world, and the country practically did not possess its own resources. A noteworthy fact is that several Australian houses built from stucco thatched 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 had difficulties - they were unable to manually dismantle the walls, they had to call in special equipment. In the 1980s, straw building became popular again, mainly due to the unique combination of heat-retaining, strength and environmental characteristics of straw blocks. In 30 years, more than 110,000 straw houses have been built in Europe, the USA, Australia and China. Since the mid-90s, several thatched houses have been built in Russia, Ukraine and Belarus. Characteristics of straw blocks
By and large, straw is a by-product and low-value product of agriculture - it is possible to feed livestock with it only after heat treatment and the introduction of additives that increase nutritional characteristics, the roofs have not been covered with it for a long time, but it is suitable only for soil mulching. Considering that cereal crops are grown almost everywhere in Russia, there is no shortage of this building material - building walls for a house with an area of 70 m2 will require straw remaining after a cereal crop from 2–4 hectares. Meanwhile, most of the straw left after harvest is usually burned. What is a straw block? It is a densely compressed bale, rectangular in shape, and consisting 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-long block with a density of 120 kg/m3 is about 22–23 kg.
Flammability of straw. Indeed, the dry stems of any plant burn perfectly, however, in a compressed state, it is quite difficult to set them on fire due to the low air content inside such a block. For example, single sheets of paper also burn well, but if you try to set fire to a folded pack of such sheets, you can only char 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 risk of its ignition is much lower than that of the walls of a wooden frame. Low price and availability of material. Blocks can be formed from straw of wheat, rye, flax, rice, and also from 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 compressed straw is reduced even more if the blocks are formed only from stalks oriented longitudinally with respect to the future wall. The energy consumption of a straw house is about 40 kWh/m2 per year, not particularly growing even in the conditions of low temperatures in the Russian climate. Reducing construction time and scope of work. The assembly of walls from straw blocks is carried out quickly, without any masonry mortar, does not require the involvement of specialists and construction equipment. Under a thatched house, a lightweight foundation, usually a columnar one, is sufficient. 
Finally, it is impossible to dispute the environmental performance of straw, a natural material that is not treated with chemicals during the construction process, since this is not particularly necessary. The disadvantages of straw walls are that insects and mice can start in them, with an increase in straw moisture content of more than 18–20%, putrefactive processes begin in it, destroying straw blocks. Both problems can be solved at the same time 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 such a dense wall, and with an increase in density, a straw block will absorb moisture worse. It should be noted that an increase in the density of blocks will lead to an increase in their weight by 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 the blocks and use lime in the preparation of the plaster mixture. DIY straw house
The walls of the house are made of straw bales, formed by a baler and tied with polypropylene cord - you need to choose them carefully. Natural fiber or steel wire strapping, 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 by round balers, straw rolls, in principle, can be rolled out and squeezed by a baler, but it is better not to do this - the straw will be strongly crushed, which will affect its thermophysical characteristics.
What is the best straw? Rye or rice straw, and winter rye straw is most suitable, because. its stem is denser, taller and, in addition, winter rye is harvested earlier than other crops. To build a house, only dry, seedless and uncut straw is required - it is not necessary to form bales from wet straw, it must first be dried. How to evaluate the characteristics 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 humidity inside it, you need to put your fingers inside, then take them out and bring them to your nose - when immersed in the straw of the fingers, moisture should not be felt, when they are brought to the face, there should be no smell of rot. Remove a few straw stalks from the bale and bend them - brittle stalks mean old and stale straw, not good 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 straw house needs a foundation, albeit lightweight, but still. Its type is determined depending on the characteristics of the soil at the construction site. To ensure the thermal insulation of the foundation and reduce the energy loss of the building in the future, you will need sheets of expanded polystyrene 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 level of the floor in the house is lower than the position of the first row of straw bales - in the event of water leaks, the straw-filled walls are guaranteed not to get wet. Next, we determine the type of construction of the house - you can build a building using a frame and without it. In a frameless house, walls made of straw blocks perform a supporting 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 a wall length of no more than 8 meters, and the area of openings for windows and doors must 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 would be optimal, the rafters of which are placed on a wooden mauerlat of two boards laid on top of the wall and interconnected by crossbars in increments of one meter. A roofing material is laid on the pre-plastered end of the wall before installing the Mauerlat. The overhang of the roofing 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 or large straw house is created similarly to the frame of panel houses. You can build a two-row frame and stack hay bales between two supporting posts. It is easier to fill the wall sections between the frame posts with straw blocks than to display 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 straw bales located one under the other, laid in a checkerboard pattern (without matching seams), the higher the rows of the wall are raised , the more long stakes are needed. The bales are fastened together after the fourth row has been laid. Also, metal bars are embedded in the basement of the building with a step of 1000 mm - their length should be sufficient to pierce the blocks of the first and second row. During frame construction, straw bales are tied with bearing poles using horizontal metal pins, and the pins that fix the blocks in place can be walled up in the foundation and brought out under the Mauerlat, stringing compressed straw on them and clamping the Mauerlat beam with a threaded connection. Neighboring walls during frameless construction are connected row by row with two pins 30 mm in diameter, curved in a U-shape. It is necessary to carry out such fastening both along the external and internal line of the interface of the walls - 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 the blocks before cutting; several pointed metal hooks for transporting straw bales. The press consists of a pole dug into the ground and securely fixed about a meter high, on which a wooden bar-lever is movably fixed. At the end of the lever, small grooves are cut, a nylon rope is fixed in them in the form of a loop. The block of straw to be trimmed is placed under this makeshift press, clamped with a looped leg, and tied with a plastic cord in a new location. The assembly of walls with hay blocks is carried out from the location of the openings and from the corners to the center of the wall. Under the bales of the first row, it is necessary to lay a fine-meshed polymer mesh as an additional protection against penetration of rodents 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 prevent convective heat transfer inside the wall. In the process of laying rows into a frameless house, it is not necessary to drive the blocks into place with considerable effort - the wooden limiters-guides, previously set along the edges of the walls, may shift. Align the 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 roof structure should not only be fixed with hammered pins, but also pulled off with plastic tapes in increments of one meter - wrapping them around the bottom of the metal pin protruding from the foundation, tying and pulling them around the wooden Mauerlat at the end of the wall. Metal tape for tying walls is not suitable, because. cuts hands and is quite stiff - it is difficult to pull. 
In the openings under the doors and windows, vertical and horizontal boards are placed, forming a box, fixed with temporary wooden crossbars nailed to the boards. The lower and upper boards of the box are displayed beyond its borders - up to half of the neighboring straw blocks. Upon erection of the wall, the boards of window and door openings are fixed with pins in bales - the pins are driven into the vertical boards inside the opening, the horizontal ones, located above and below the opening, are fastened outside it. Before fixing the opening box, it is necessary to overlap roofing material or roofing felt under the boards, lay a plastic or metal reinforcement mesh on top of it with an extension of the edges of the opening by 300 mm and fix it with 35 mm galvanized nails or 35 mm building 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 a nylon thread or steel knitting wire pierced through the straw through and through. To sew a straw block with a 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 conventional 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 laying, you will need a chainsaw. Before the next stage - applying plaster - wired communications are brought into the wall in a cable channel made of self-extinguishing polyvinyl chloride. Pipes for water supply, heating and sewerage are not placed in a straw wall, because. cause moisture condensation and rot. The final stage of work on the creation of straw walls is the application of two layers of plaster. Nuance - if blocks with a density of 200 kg / m3 and above 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 vapor-saturated air through the wall, in other words, it will prevent the wall from “breathing”. Suitable plaster solutions on a clay-lime and cement-lime basis, having an average fat content. 
The proportions of the 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 (lime dough mixed with water to the consistency of milk). The sifted cement and sand are mixed in dry form, 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, the leveling second layer - 2-3 mm, it is done with a creamy plaster mortar. After the plaster has dried, the walls can be painted with water-dispersed paints - oil paints will not work, because. act as a barrier to the air exchange of the walls. Straw walls need to 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. between the straw wall and the cladding there will be enough space for their life. In addition, panel and brick cladding of non-plastered walls increases their combustibility due to the same gaps. And yet - you should not use a vapor barrier of thatched 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 laying of the walls, until they are completely covered with plaster and the perimeter is completely cleaned of spilled straw, it is strictly forbidden to smoke, weld and other types of work with heating to high temperatures, using an open flame and accompanied by sparks at the construction site. Uncompressed straw ignites easily, 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 equipment - barrels of water, charged and serviceable fire extinguishers, hooks. If a fire does occur, you need to quickly sweep the walls with hooks and fill the smoldering blocks with water - it is important to prevent the wooden frame from igniting (in the case of a straw frame house), because. new straw bales will cost significantly less than a new frame. At the end
Straw houses undoubtedly have great prospects - in combination with eco-house technologies, cheap, consuming a minimum amount of thermal energy in the cold season and independently air-conditioned houses made of straw can give their owners more than just environmentally friendly housing. Abdyuzhanov Rustam, rmnt.ruRecently, I came across an interesting video material. Watching a video on how to build a house out of timber, I noticed another story - about how to build a house out of straw with your own hands. And having looked, I decided to write about it.
The video was filmed by the settlers of the Ark.
It turns out that the price of building such a frame house of clay and straw is not very high. The technology is also not very complicated. The house is warm. The plot itself shows how to build a frame house from clay and straw, tells the terms of work, the price of construction, the technology for pressing clay with straw. The video is definitely worth watching even just for the sake of your own development. Yes, and suddenly, it will come in handy in life!
The return to partially forgotten building technologies is associated with the trend of using natural materials. They give houses a natural coziness and have good environmental qualities. A classic example of such buildings are adobe houses, the main material of which is a mixture of clay and straw. The buildings gained their popularity for their environmental friendliness, natural regulation of the microclimate in the room and relative simplicity.
Samani house. What it is?
Analogues of modern houses made of straw and clay existed in ancient times. Some of them have survived to this day - in the arid regions of Asia and Africa, you can find entire adobe cities. The improvement of building technologies has led to the widespread distribution of clay buildings in central Europe and modern Russia. Properly built clay houses have more than a century of service life and are safe for residents.
Visually, adobe buildings do not always differ from ordinary ones, although their main “charm” lies in the ability to give the walls an arbitrary shape and adapt them to home interior items. Numerous recesses, baths and smooth transitions strikingly distinguish clay buildings from brick and other block-cement structures.
Old technologies are rarely applied in their original form, since the performance parameters of modern homes are improved through the use of modern additives. The natural fire-fighting properties of clay, which is prone to baking at elevated temperatures, are improved by the introduction of components that increase strength characteristics.
Clay construction technology
1. Materials that should be stocked up in advance:
wooden boards and beams for building the frame of walls and roofs;
clay;
sand;
straw;
water (well or centralized water supply).
Additional materials that will be useful during the preparation and finishing stages include:
gravel - for the preparation of bedding under the foundation;
material for the manufacture of a solid or brick foundation;
flat wooden planks for upholstery of the walls of the house;
wooden (metal) formwork or mold for making blocks.
Although the house will be clay, it is better to make its foundation classic - tape. A solid and elevated base will increase the life of the house and reduce the impact of melt water on the lower part of the walls.
The place for construction should be chosen away from lowlands and access to the surface of groundwater. The optimal location of the clay house is on a hill.
In order to obtain the most durable building suitable for our latitudes, the walls are best made by pouring mortar into the formwork. You can also use clay blocks, which are laid similar to classic block structures.
A significant reduction in the cost of construction is achieved through self-extraction of clay on your site. Straw in small quantities is cheap, and the largest costs will be associated with the purchase of sand and lumber.
The straw must be dry, without rot. It is best to buy it immediately after the harvest season, and then leave it for the winter in a dry and ventilated area.
2. Solution preparation
Many authors advise using not pure clay, but its mixture with sand. Since clay and sand differ in composition for different regions, you can test their different proportions (2:1, 1:1, 1:2, etc.). The clay-sand mixture, to which water is added until a pasty consistency is obtained, should be squeezed in a fist and dropped onto a solid base from a height of 1.5-2 m. A lump of a suitable composition should not split or flatten strongly when falling.
To prepare the solution, you can use a concrete mixer or a flat base with edges curved upwards (stir the solution with your feet). Clay is crushed to a finely dispersed state, after which sand and water are added to it. The latter should not be much so that the mixture retains a highly viscous consistency and does not flow out of the formwork.
Straw is added to the resulting clay-sand solution in an amount of 30 to 60%. The more straw, the lower the thermal conductivity of the walls and their strength (you will have to limit yourself to one floor). The resulting solution is poured into the forms of formwork, exposed along the edges of the wooden frame of the house.
The frame is assembled from beams and consists of vertical and horizontal guides. On top there should be a blank for the roof, because after pouring the walls, you must immediately start covering it. The solution is poured in steps (up to 30 cm per day), after which the wall should be allowed to dry. With independent construction, the wall usually "grows" by 10-15 cm in one day cycle.
Outside, the walls are covered with a crate of straw or reed - they create an additional heat-insulating layer. The crate is fastened with a thin layer, which is pressed against the wall with wooden flat planks (nailed to wooden supports). Outside, the crate is covered with clay or lime plaster.
3. Roof made of straw and clay
On top of the roof frame, upholstered with boards, tied sheaves of straw are laid, which are then leveled (the rope that fastens them is cut). They fix the straw in the same way as the crate on the wall - with wooden slats. After covering the roof, you can start coating it with a clay-sand mortar.
The process is carried out from the lower edges of the roof to the ridge. After hardening, the coating will not let moisture through, but will leave the room able to "breathe" and maintain humidity at the optimum level of 50-55%.
Feature: the pouring of the roof should be done alternately and evenly on both slopes to avoid skew.
4. Finishing the walls of the room
What is the difference between modern houses and old buildings?
To give additional tensile strength to the clay solution (straw partly copes with this), cattle dung was widely used in the past. The same solution plastered the walls of the room, called the "hut". The main disadvantage of such houses is the abundance of insects in the walls.
Now natural chaff and fire are used to increase strength. A couple of centuries ago, they were difficult to get, and now they are waste from plant processing.
view of the adobe house
An increase in strength and a decrease in shrinkage during drying is increased by the addition of crushed stone or expanded clay. The auxiliary element is sand. To increase the rate of hardening, cement or lime can be added to the clay-sand mortar. Their additives are used in construction in wet weather, aiming to reduce the risk of wetting the still wet wall material.
Casein, starch and liquid glass help to increase the viscosity of the solution during operation. The latter is an antiseptic, therefore, it additionally prevents the appearance of mold and insects.
The use of modern construction technologies, including the sublimation of a strong foundation, increases the strength and stability of the building. Instead of a clay roof, you can lay out the usual roofing material, which is closed on top with slate or tiles. This will not worsen the environmental properties of the house, but will improve performance.
To protect the house from rodents, it is necessary to provide for the presence of a thin metal mesh under the crate.
Peculiarities of caring for thatched houses
A separate item in the operation of buildings is fire safety. Clay houses, which are coated with clay or lime mortar on the outer and inner surfaces, are less prone to destruction in a fire than ordinary ones. When a flame occurs, the straw in the walls does not ignite, since air access to it is closed by a layer of clay.
house wall made of clay and straw
Despite the high resistance to fire of the walls of adobe houses, the wooden parts of the roof do not possess it. To reduce the likelihood of their ignition, wood should be treated with flame retardants. They do not provide absolute protection against fire, but are very effective if the application technology is observed.
Construction companies involved in the construction of houses from clay and straw assure the practical impossibility of the appearance of insects in the walls. This is true only when maintaining low humidity, which is not always possible. Do not neglect the advice to use lime plaster, which will clog the walls for moisture and will inhibit the development of insects.
Before building a house, consider the location of the stove and bathroom. In places of contact with heated surfaces, reflective screens should be placed, and in wet places, waterproofing should be performed.
Adobe house: the pros and cons of the building
Advantages of adobe buildings:
clean and healthy "atmosphere";
indoors cool in summer and warm in winter;
low cost of building materials;
relative ease of construction.
About the features of houses made of clay and straw, as well as the personal experience of building the author, see the video:
based on the Internet
Unlike manufacturers of modern finishing mixes, clay plaster is indeed an environmentally friendly building material. It has undeniable advantages, and its technical and operational characteristics are quite sufficient to solve most problems in construction.
About this, and about the varieties 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, log house or structure made of logs.
Plastering wooden walls inside the house with clay, photo of a living room with a fireplace
Advantages:
- The cheapness of the material;
- Absolute safety for the environment and for humans;
- Possibility of fast and safe disposal or reuse;
- Vapor-permeable material capable of regulating the humidity in the room;
- Non-flammable, when heated to critical temperatures, does not emit carcinogenic or toxic substances.
Flaws:
- Requires experience and accuracy in finishing;
- Sensitive to moisture;
- It is necessary to reinforce the walls with a metal mesh or shingles.
Traditional and modern compositions
One of the oldest recipes for making clay mortar for wall plastering has the following proportions:
- Clay 10 parts;
- Sand 5-8 parts;
- Straw 5-10 handfuls.
Such a large spread of sand occurs because clay in different regions has a different fat content. The fatter the clay, the better its plasticity and higher adhesive ability. The fat content of clay for plastering walls is determined simply. 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 the hands. Then the ball is squeezed in the middle, if it turned into a neat pancake, then such material is greasy and suitable for clay plastering, and if it cracks at the edges, then such material is skinny and unsuitable for wall decoration.
Refractory compound
On sale there are numerous ready-made refractory compositions with the addition of lime, gypsum or cement binder. However, for plastering ovens, it is enough to use fireclay clay, and fiberglass as reinforcement. Previously used asbestos fiber, but it is too harmful to humans.
Finishing the furnace with clay plaster, composition with fireclay clay
Moisture resistant compounds
Clay plaster with the addition of a small amount of cement, in the proportion of 1 part cement to 7 parts clay-sand mixture, obtains a fairly high resistance to moisture. at the same time, it can absorb up to 60% of moisture from the atmosphere, which has a positive effect on the microclimate of the bathroom.
Bathroom finishing
Warming compositions
The traditional material for insulating plaster, horse dung, is now quite scarce, so the plaster of a wooden house inside with clay for insulation is made with sawdust, which is kneaded into a standard mixture, but without adding straw. Plastering a wooden house with clay and sawdust is done exclusively indoors.
Applying plaster
The main way to avoid cracks when plastering with clay mortar is to use reinforcement with metal wire or to carry out shingling of walls. In addition, the ratio of ingredients is slightly changed towards reinforcing substances of natural or artificial origin. Add more straw and less sand. Such a ball of plaster is intermediate, as it does not have a very neat appearance.
A solution with a large amount of straw avoids cracks
Video of the process of plastering the clay walls of a house from adobe (adobe):
In fact, straw has excellent adhesion, and therefore it can be plastered with anything - everything will equally apply and hold well.
However, today we will analyze two main types of plaster: cement and clay.
Some people mistakenly believe that clay is not strong enough for a thatched house and, in order to strengthen its strength, decide to plaster the house with cement plaster.
And everything seems to be fine, the house is perfectly protected from external influences, but what is the danger?
The bottom line is that clay plaster reliably protects straw walls and does not allow moisture to pass there.
Cement plaster, quite easily passes moisture both into the straw walls and back, forming condensate.
In order to give a more detailed answer to this question, let's turn to the chemical properties of these plasters. There is such a thing as hydrophilicity. In general, it shows how much the material loves and attracts water.
So, clay is more hydrophilic than straw, and therefore, all the water that is in the straw, the clay draws into itself, and then it evaporates.
At the same time, cement is less hydrophilic than straw, and therefore, all the moisture that is in the walls, the straw begins to absorb into itself. What does it threaten? After the straw has absorbed all the moisture, it will begin to become covered with mold, fungus, and in the end, it may simply begin to rot.
Now the second question: where can moisture come from in the walls if the wall is reliably plastered?
Moisture tends to move from hot air to cold air. In addition, it moves from high pressure to lower pressure. As a rule, the pressure inside the house is always much higher than outside, so all the moisture that is in the house (from the shower, kitchen, plants, sweat, etc.) gets inside the walls.
Further, if the wall is plastered with clay, then it delays the movement of water in the wall and at each stage the moisture gets less and less to the straw. But even the moisture that gets there is pulled back into the wall by the clay, due to its hydrophilicity.
If the wall is plastered with cement, it does not have such waterproof properties and passes much more moisture to the straw walls themselves, which is successfully absorbed by the straw in the future.
Therefore, one conclusion can be drawn: based on their chemical characteristics of these materials, it is not advisable to plaster the straw with cement, because in the future this can lead to its decay.
At the same time, clay plaster is much healthier, cheaper and easier to work with, and will also protect your thatched walls from damaging moisture.
