Houses made of straw. Straw house: modern straw technologies

Good afternoon Remember the fairy tale about the three little pigs? One of them had a dwelling made of straw. But, unfortunately, it did not bring happiness to its owner. Our fascinating portal, without being lazy, found a selection of houses made of such material in which not only fairy-tale characters, but also people can live comfortably and be completely satisfied with their lives.

How quickly everything is developing! The need for efficient and environmentally friendly designs is becoming stronger and more obvious. Designers and architects are constantly looking for (and finding!) new options for using materials that will help them achieve their goals.

That's why we see all sorts of unusual designs. For example, houses made from recycled waste or underground structures. Straw is also an interesting alternative.

Small eco-house in the forest in Southern Finland

Let's take this cute cottage. It can be found in Finland. It was built for summer holidays. This is a small room in shabby chic style.

It was built gradually, from sand, stone, waste wood, straw and other natural materials. The walls are adobe and the outside is plastered. Friends and neighbors of the owner took part in the construction. It may not be as spacious or fancy as some, but it's all about relaxation. For example, the fact that the interior is illuminated by candles.

In order to somehow expand the small space of the structure, the builders found a way out in the form of a ceiling window. The idea was a great solution that allowed the owner to admire the starry night sky and watch warm drops of rain flow down. The roof was originally constructed from a pile of cardboard and tarpaulin. We can say that it never happened. Now it is wooden with a waterproof layer.

The small window at the back is well secured with plaster on the walls. Perhaps the home is not the most perfect creation on the planet, but such a building is enough to spend a few summer days in it and escape from daily problems.

Hobbit House

This is what he looks like

When you imagine houses made of straw, the fairy tale home of the Hobbit probably comes to mind. Today, many architectural firms use the design idea of the habitat of this fairy-tale character in their projects of environmentally friendly buildings.

The house was built on a hillside and has a very original design. Its owner decided to start this project primarily because he no longer wanted to pay off huge mortgages to build or buy his home. As you can see, the solution to the problem was found when inspiration struck its owner.

The owner of the house was not a professional architect, but this did not bother him at all. He began construction by collecting scrap, wood and other building materials. After just four months everything was ready.

The house has an amazing and magnificent interior, it is charming and attractive. Why not live in it? The refrigerator here is cooled naturally. Plus there are other cute features. The house is compact and inspires new exploits.

Straw bale frame

Eco-friendly house from ModCell

As a rule, buildings made from the material in question are small in size, shabby in appearance and definitely do not look like the wonderful creation demonstrated in the photo.

It is a prefabricated structure built by British company ModCell, which offers an innovative approach to traditional straw bale construction. The house they built is modern and quite spacious, not to mention very attractive in appearance.

Modern home interior

Dining room interior

It must be said that the buildings are sustainable and energy efficient. The company uses compressed dried grass, which provides good insulation and stability. Blocks and wall systems are built from lumber filled with local straw or hemp.

As a result, very important qualities are achieved: air tightness, anti-mold effect and stability. This type of construction proceeds with virtually no waste.

Wooden staircase

Modern furniture in the dining room

The outside of the dwelling is covered with rendering lime. In addition, straw panels can be successfully used in the construction of any houses. You can safely use them when developing several levels. Modern open-plan houses with large panoramic windows are built in this way. This is a simple example of what can be built from the material.

Straw bale housing for Carol Atkinson

Either a house, or a huge bale of straw (at the creation stage)

Here is another example of amazing housing. It is, in fact, the first such building in the UK. It is quite suitable for spending a holiday there. Located in East Yorkshire, it is popularly known as the "straw bale cabin".

It is an eco-friendly structure that was built using grass grown and recycled from local farms, as well as a number of other materials given a second life. To make the house more sustainable, the owner placed a micro wind generator on its roof, which generates energy for the needs of the residents.

Home in all its glory

Pond nearby

Roof structure

Living room

The house can be rented to those who want to live in such a building, enjoying peace, tranquility and clean air. From the outside it looks very simple, but in fact the appearance is deceptive - a much more complex structure is hidden inside. The place is ideal for solitude and spiritual practices; from here you can be transported to a completely different world.

Sustainability and energy saving

One of the stages of construction

When such buildings were first conceived, it was expected that the result would be something shabby and unattractive, waiting to be replaced by something better. But as it turns out, we can now truly appreciate straw houses due to their low cost and significant energy savings. Many designers began to recognize the benefits of such structures, and soon a number of similar projects were created.

Beautiful building

Bale cutting

The program is aimed at developing energy-efficient, environmentally friendly structures and methods of their construction. Making a straw bale house turned out to be the best solution. The material became more popular after people began to appreciate the benefits it offers.

Such housing is easier to build, investments are minimal, and it offers more advantages in terms of energy saving. This is the first step towards a more harmonious future.

There is an increase in construction using eco-materials all over the world, and the results are already impressive. The value of the project also lies in the fact that many people are beginning to think about changing their usual lifestyle.

The first dry grass house in Rome

Old building

Contrary to general belief, houses made from eco-materials are not only suitable for rural areas. In fact, they can look quite charming and fit nicely into the urban landscape.

The Officinamobile group of architects knows this very well, and that is why they are trying to change the stereotyped attitudes in people's minds. The team recently built remarkable block buildings in Rome, the first of their kind in the city.

The bale was initially mixed with crushed bricks and earth. The walls are plastered with a mixture of crushed shell rock and local mud. It may not sound very attractive, but the resulting result is surprisingly beautiful. In fact, this coating gives the house a very beautiful earthy tone that makes it feel especially warm and cozy.

The goal of the project was to create an energy efficient space with a sustainable design that would fit perfectly into the terrain.

Earthquake-resistant houses

In Pakistan

As we mentioned earlier, the buildings are extremely environmentally friendly and energy efficient. But there is also another valuable quality they can offer. These structures are earthquake resistant. That is why they are a wonderful alternative and a real salvation for some regions.

A group called PAKSBAB has already started a program in which durable buildings are created using local resources.

These dwellings are built according to inexpensive designs using eco-materials. Seismic resistance is the most needed feature in them. They are able to withstand the destructive force of earthquakes. Oddly enough, it is straw bales and bamboo that give buildings this property.

Construction of the century

Final stage

The panels serve as load-bearing structures and means for insulation. The walls are covered with clay plaster. This is a great innovation and also low cost. Construction costs only $2,250 - this is the total cost of the materials used. The structure of the building is simple and does not require much effort to implement. The group of architects who built 11 such structures is a great success all over the world.

Eco-houses

Nice little mansion

Man is constantly looking for alternative materials that can help him improve his quality of life. Today, the negative impact of construction methods and materials used on the environment and human health is of particular concern. Therefore, the process of finding ideas to solve a problem is an important part of the work. Modern companies focus their efforts on the use of natural materials.

Construction team

For example, the amazingly beautiful and original building in the photo is built from natural raw materials. It is located at the top of the slope, offering a wonderful panoramic view, and looks quite majestic. Its shape is rectangular and the overall design is simple. As you approach the building, it becomes noticeable that it is built of timber. But no one will see that it is filled with dry grass.

The raw materials provide thermal insulation and allow the structure to be strong enough to support the roof. It took about 700 bales to build the living space and workshop. The creation process itself is simple, but it takes time, so the more volunteer helpers you have, the better. This is another big project that inspires us to accomplish new feats.

Another plan of action

All examples of buildings presented are large in volume and encourage one’s own creativity. But before you start sculpting yourself, you need to find out in what area the implementation of such a program is allowed. Construction itself will not cost a lot of money, but it will require time and effort. Prefabricated houses will be even easier to make if you think about the right frame from the very beginning.

Home construction

After completion of work

Straw bales are used only for filling walls. The base of the structure is made of wood, which is a successful and organic addition that will bring more warmth to the building and lead to energy savings. It is best to plaster the walls. In terms of design, don't expect a flawless appearance. It will be more of an organic interior with irregularities and unique details. You can try to round off the protruding corners for greater beauty.

Three times more efficient

Construction

We have looked at the main advantages of eco-buildings, let's summarize. Firstly, the material is three times more efficient than that used in the creation of conventional houses. Costs are reduced by up to 75%. Secondly, the life cycle of such a structure is about 30 years. Thirdly, excellent thermal insulation does not require additional means for heating. And fourthly, the costs of transporting raw materials are minimal.

And one more wonderful property. Walls made of dry processed grass “breathe”, they have a special charm - the living structure creates an extraordinary indoor climate.

One of the stages of construction

Continuation

The material retains heat inside and maintains a constant temperature. Clay is used to coat bales and absorb dirt. It is a renewable resource that is also considered more sustainable and has better fire protection properties than wood.

The walls can support weights of over 1000 kg/m2 and are easy to construct. The mixture used for plaster is made from earth, straws, sand and plants. A house with an area of about 100 m2 can be built in 3–4 months, which in itself is very attractive. Currently, such construction is gaining momentum, and you can find unusual mansions not only in rural areas, but also in cities.

Today, the materials used in the construction of houses are extremely diverse. Housing is built from aerated concrete and, or logs, brick or stone. Along with these popular materials, straw has recently become increasingly preferred, making it possible to build a warm and reliable structure on a very modest budget. If all building technologies are strictly followed, a house made of straw can be much warmer, cheaper, stronger and more reliable than its stone and brick “brothers”.

Project of a modern eco-friendly straw house

The first thatched houses began to be built in America in the middle of the 19th century. Very often, the wood that was used in the construction of structures was not enough, but there was an abundance of straw in the fields. The first officially registered house made of straw is considered to be a school building in Nebraska at the end of the 19th century, the walls of which were completely eaten by cows a few years later. This is probably why compressed straw blocks began to be supplemented with a strong frame made of logs in the very near future.

A little later, the construction of houses made of straw for a wide variety of purposes began in full swing, the area of which reached 70 square meters. m. These were schools, shops, residential buildings, cowsheds, vegetable stores and even small luxury estates.

However, already in the middle of the twentieth century, straw house construction, as a result of the advent of more modern construction technologies, began to gradually lose its position. Despite this, the idea of building inexpensive and yet reliable structures did not leave people's minds. At the end of the last millennium, these ideas grew into a whole movement.

The interest of architects was of greatest importance for the popularization of straw houses, thanks to which buildings with the most unusual architectural and planning solutions began to be erected in America. The resurgence of straw bale construction was supported by television and print media, including the New York Times and National Geographic magazine.

Gradually, houses began to be built in a variety of climatic zones and countries: Australia, Chile, Canada, Mexico, France and, naturally, in the USA. In Russia, the very first straw bale house was built in the village of Mayak (near Chelyabinsk) in 1994. Houses made of straw bales with various fillers (clay, sand, slurry) were known in Rus' as adobe houses. In warm regions, such construction is still popular to this day.

How to build a straw house with your own hands

Blocks of pressed straw measuring 35*45*90 cm are used as a building material. They are tied with nylon cord or wire. When making blocks, flax, rye or wheat straw is used; in addition, you can use hay. It is worth noting separately that the straw in blocks is usually pressed so tightly that it is impossible to burn through the bale even with a blowtorch. Thanks to this, straw houses are not exposed to moisture. Raindrops can penetrate the treated walls and roof no deeper than 5 cm.

Blocks for construction are usually made in a rectangular shape. Their size depends on the length of the stem: the longer it is, the larger the block and, accordingly, the more reliable. During construction, you can use not only dry straw blocks, but also those soaked in clay mortar. Before starting installation work, the compressed bale is dipped in a clay solution, and then thoroughly dried for a certain time. Thanks to these actions, it is possible to achieve precise wall geometry, as well as high fire safety and strength.

A little history

For the first time, ancient African tribes began to build thatch houses. In Europe, straw was used only as thermal insulation - it was used to cover attics to insulate the roof. But not so long ago (a little more than a century and a half ago) a completely different technology for constructing houses from straw was developed. It was quite simple: a wooden frame was erected and filled with straw blocks, and the roof was covered with boards.

During the colonization of America, settlers also built houses from straw, but this was rather a necessary measure, since wood was in short supply in the lowland areas. In 1925, the production of straw panels began, in which the stems were tied together with steel wire. The panels themselves were covered with cement-clay mortar. Houses made from such blocks are characterized by durability. By the way, when demolishing them, workers often had to resort to the use of special equipment.

It is worth noting that “straw” construction in some Western countries continues to this day.

Features of the material

Straw is a waste product from growing agricultural crops. It can be used to fertilize the soil and also as feed for cattle, but most of the straw is still burned directly on the fields.

To use straw as a building material, it must be compressed into a block. Such blocks come in different sizes, but usually they are 100x40x50 cm. Average weight is 20-25 kg, density is 110 kg/m?.

Main advantages

Flaws

The straw house has only two of these:

rodents;
rot (at a humidity level of more than 20%).

But these are rather temporary difficulties that are quite easy to cope with. To do this, the blocks are pressed harder (up to approximately 250-270 kg/m?), and a small amount of lime is added to the plaster. But it is worth remembering that the denser the block, the greater its weight.

Important! When laying the blocks, you can additionally sprinkle them with slaked lime.

When building such a house, you need to strictly follow the instructions, and also prepare everything you need in advance:

Stage 1. Material selection

Raw materials must be of high quality. Experts advise using winter rye straw for construction, which is the most suitable option due to the high density of the stem. You also need to ensure that the material is dry and without seeds.

Today, bales that can be used to build a house are tied with plastic cords. Bandaging with natural fibers (they quickly rot and are not very strong) and wire (metal will rust sooner or later) is unacceptable.

Stage 2. Construction of the foundation

The foundation for a thatched house, although lightweight, still needs to be equipped. The choice of one type of foundation or another depends solely on the characteristics of the soil on the site, but the best option, as mentioned earlier, would be a pile structure.

First, geological exploration is carried out to determine the level of soil freezing. Screwed piles must reach this level.
Then the corners of the house are marked, small holes are made in them and corner piles are screwed in. After this, the remaining piles are screwed in symmetrically around the entire perimeter.
The piles are cut at a height of 0.5 m above the ground, and a frame is installed on them.

Important! When cutting piles, you need to use a building level to accurately determine the required height.

If a foundation of a different type is chosen, insulation will be required. For this, it is recommended to use foam plastic slabs with a thickness of at least 10 cm. It is important that the slabs are also installed below the freezing level of the soil.

The “clean floor” of the house should be below the first level of straw blocks - this will protect the walls from getting wet in case of a pipeline leak.

Stage 3. Construction of the frame, assembly of walls

A straw house can be with or without a frame. If you choose a frameless option, then you need to adhere to certain rules:

the length of the walls should not exceed 4 m;
the density of the blocks must exceed 200 kg/m?;
the roof structure needs to be made somewhat lighter;
the house should have only one floor.

In a word, you can do without a frame, but in this case there will be restrictions during construction. Therefore, it is better to take care of the frame (metal or wood).

Important! The technology for assembling a frame for a house made of straw is practically no different from a similar procedure for panel buildings.

The frame is made in two rows so that the blocks are placed between the supporting pillars. This should be done in a checkerboard pattern so that there are no seams between the blocks. Each filled span is pierced from above with a wooden rod about 6 cm. The bales are pulled together horizontally only after the fourth level.

Assembling the walls should begin from the corners, heading towards the center. A fine mesh net is installed under the first level of blocks to protect against insects and rodents.

If the foundation is poured, then reinforcing bars with such a height are installed every meter so that only the lower two levels of blocks are mounted on them. To fasten adjacent walls, U-shaped brackets o3 cm are used, two pieces for each corner.

Then a Mauerlat is constructed around the perimeter of the walls, and a metal pin is installed in one corner of the structure. Take plastic tape, attach it to a pin and tighten it around the entire house.

Stage 4. Openings

Window and door openings are mounted approximately in the center of the installed blocks. The internal surfaces of pre-prepared holes of appropriate sizes are lined with roofing felt and reinforced mesh (the latter extends approximately 30 cm along the edges). The outlets are attached to the wall with a mounting stapler, and boards are nailed on top.

Stage 5. Plaster

Once the walls are assembled, you can begin plastering them. Before starting work, the outer and inner surfaces of the walls are reinforced.

Important! This must be preceded by the installation of all necessary communications, and the electrical wiring must be in special cable channels.

Pipes should not be laid inside thatched walls as this will lead to condensation and therefore rot. After wiring everything necessary, plaster is applied. She may be:

clay-limestone (made of clay, sand and lime in a ratio of 1:3:0.5);
cement-lime (cement + sand in a ratio of 1:4, while stirring, lime mortar is added from time to time until the mixture reaches the required consistency).

Cement plaster is unacceptable in this case, because the walls covered with it will not be able to “breathe,” which is unacceptable for straw. The solution is applied in two layers.

Important! If the density of the material exceeds 200 kg/m2, then the plaster can be applied immediately after completion of assembly. If the density is lower, then you should wait a few days for the straw to settle and compact.

The thickness of the first layer should be at least 3 cm, the second - 1-2 cm. After applying the plaster, the walls dry for several days, after which they are painted.

Important! Oil-based or water-based paint is not recommended for the same reason as cement-based plaster.

Video - Plastering a thatched house

Common myths about straw

Myth one. Straw is an ideal habitat for small pests.

Rodents will not be able to penetrate the compressed material covered with reinforcement and plaster. Moreover, they do not eat rye straw at all, and the required humidity that we talked about (no more than 20%) is destructive for insects.

Myth two. Thatched walls are easily destroyed.

In reality, such walls are quite strong. Research was carried out in Canada, during which it was found out that tied straw blocks can withstand up to 350 kgf of lateral load.

Myth three. Straw doesn't last long

History clearly demonstrates the opposite: straw houses built in Western Europe several centuries ago still look great today.

Myth four. Straw is flammable

This was already mentioned at the beginning of the article. The straw can only burn a little, but even this is quite difficult to achieve.

conclusions

Straw houses have many advantages - low cost of construction work, environmental friendliness, low heating costs. And even if such technology is not yet very popular today, there is every chance that it (popularity) will grow over time.

Video – Thatched house (walls)

Houses made of pressed straw, built using frame technology, can be built from:

straw blocks;
straw panels.

Straw bale construction:

To build a house from straw blocks a frame is used that resembles the frame of a panel house. The frame is made from beams of a traditional square section. The frame is filled already under the roof, to avoid getting the straw wet.

The wall space is filled with tightly compressed straw blocks, which are fastened to the base and to each other with metal stakes. The blocks can be located both inside the frame and on the outside. Before laying the blocks, the frame is covered with a metal mesh; it will be needed for the convenience of applying a layer of plaster.

The construction of load-bearing walls made of straw is carried out according to the principle of brickwork. Straw blocks are stacked on top of each other, and strict care must be taken to ensure that the seams of the blocks do not coincide. The blocks are laid so that the vertical seams do not coincide. For a tight and strong adhesion, the blocks are secured to each other using metal rods of different lengths. The lower blocks of the first and second rows are placed on pegs fixed to the foundation at a distance of about 1 meter. The next rows are secured with additional rods. As the rows are laid out, the rods are built up and secured to each other.

The result is a long pin extending across the entire height of the wall. Its lower part is mounted in the base, and the upper part is threaded. For a tighter tie, a nut is screwed onto the top of the rod.

Construction using compressed straw panels:

Homes from straw panels are built faster, easier and more efficiently than similar frame ones with straw bale insulation. The secret lies in the largest segments of the walls of the house, which reduces the labor effort during assembly, transferring it to the equipment. Traditionally, this is a concrete columnar or strip foundation and a wooden floor, frame, and roof. A crane or a good team can assemble modular sections of a thatched house within 1-2 days if it is one-story.

The Malt company builds houses using this technology.

Compressed straw wall panel:

The pressed straw wall panel is a double wooden frame. Straw is pressed into the frame using a hydraulic (or any other) press. This is necessary so that over time the straw does not shrink, secondly, pressed straw, even without a layer of plaster, is difficult to ignite (the “closed book” effect), and thirdly, mice and other living creatures do not start in the pressed straw as it is very difficult to move.

The double wooden frame is load-bearing and takes on all external loads - snow, wind and internal loads from the own weight of the roof, rafter system and attic floor, if there is one.

It is important to use dried and calibrated wood when producing panels. Lay the straw perpendicular to the plane of the panel for the best “biopositive” effect. The straw must be dry. During transportation and installation, it is also necessary to protect the straw panel from getting wet.

The standard panel has dimensions (w*h*t) 1000*3000*450 or 1250*3000*450. These standard sizes allow you to load a house kit with an area of S=115 m2 into one standard truck.

Panels of the required width and height are made for the windows and doors.

Stages of building a house from straw panels:

Pouring the foundation;

A house built using straw technology is much lighter than traditional ones.

The main task of the foundation- load-bearing, so it is possible not to make it as massive as is customary for other construction technologies.

M The minimum width of the straw wall is 49-56 cm. The straw panel or straw bale must stand on a wooden wall that is moisture-proof and securely fastened to the base. It is recommended to make the foundation at least 35-40 cm high to protect the thatched wall from getting wet during heavy rains.

For houses built using straw house construction technology, almost any foundation is suitable; it is selected based on the needs and capabilities of the owner of the house (read more in the article about the types of foundations for a house built with straw panels).

Assembling the external walls of a house from straw panels:

Assembling the outer walls of a thatched panel house begins by positioning the corner panels and securing them to support boards mounted around the perimeter of the house.

After fastening, the panels are fastened together and tightened on top with a Mauerlat.

On average, installation of panels takes two days.

Installation of rafter system, roofing, organized drainage, electrics;

Plastering the walls of a house made of straw panels, blocks:

Using straw house construction technology, the walls of the house are plastered in three layers with clay plaster. The process is labor-intensive and time-consuming - it takes about 4 weeks.

Read more about building a house from straw panels in the article.

Interior decoration of the house:
At the final stage of construction, communications are installed and the interior decoration of the house is completed.

Houses built using straw house construction technology are energy efficient, they are three and a half times
Warmer than brick houses, in winter they can save up to 86% on heating due to the fact that they store heat well. In summer, such houses are cool; the straw panel plastered with clay does not let heat into the house. An air conditioner is not needed in such a house; it will be cool in the summer even without it.

Houses built using straw house-building technology have biopositive qualities, this is due to the unique, scientifically proven property of straw to equalize the human biofield and heal the body.

Houses with pressed straw insulation are environmentally friendly, since only natural materials are used in construction. You can be sure that your family will always be safe from deadly harmful fumes from various chemical building materials.

Fire safety of a house with compressed straw insulation:

Houses made of straw panels and blocks have the highest degree of fire safety. This is because well-compressed straw blocks and panels have good fire resistance, as they leave virtually no room for oxygen, which is necessary for any material to burn. In addition, at the final stage, the straw walls are covered with a thick layer of clay plaster, which further increases the fire safety of the structure.

Thatched houses are no longer a revelation for many, since their number is increasing every year. This cheap material has excellent technical properties and is easy to use.

The very idea of building a straw house is difficult to perceive, because in the well-known childhood story about the three little pigs and a hungry wolf, Nif-nif’s straw house looks completely unreliable.And why would anyone build a house from waste left over from the harvest season? There are time-tested construction materials that make it possible to build a solid and durable building.

Thatched house

True, classic building materials today are not cheap and have quite a lot of weight, and the walls formed by them have to be additionally insulated. We propose to study the technology of a thatched house and find out whether it makes sense to create such houses in the temperate climate of Russia.

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 straw attic insulation were very popular in Europe, Russia and Ukraine back in the 19th century. More than 150 years ago, a new technology for building thatched houses appeared - a wooden frame, plank roofing and walls filled with blocks of compressed straw.

European settlers, actively exploring the territory of North America, were faced with a shortage of timber in the flatlands 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 soils turned out to be so poor that it was impossible to remove the turf 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 clay-lime mortar with chaff mixed in it.

The increased need for straw bales led to the invention of mechanical stationary balers in 1850 and movable straw balers pulled across fields by horses in 1872, followed by 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 had practically no resources of its own.

A remarkable fact is that several Australian houses built from plastered thatch 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, workers unexpectedly encountered difficulties - they were unable to dismantle the walls manually and had to call in special equipment.

In the 1980s, straw house construction became popular again, mainly due to the unique combination of heat retention, strength and environmental characteristics of straw blocks. Over 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 Bales

By and large, straw is a by-product and low-value product of agriculture - it can be fed to livestock only after heat treatment and the introduction of additives that increase nutritional characteristics; roofs have not been covered with it for a long time, and it is only suitable for mulching the soil.

Considering that cereal crops are grown almost everywhere in Russia, there is no shortage of this building material - erecting walls for a house with an area of 70 m2 will require straw remaining after a cereal harvest from 2-4 hectares. Meanwhile, most of the straw remaining after harvesting is usually burned.

What is a straw block? It is a tightly compressed bale, rectangular in shape, consisting of dried cereal stalks 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, dry stems of any plant burn well, but 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, individual sheets of paper also burn well, but if you try to set fire to a folded stack of such sheets, you will only be able to char them at the edges - the same thing happens with a compressed straw block, despite the high flammability category G4.

Since a 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 fire is much lower than that of the walls of a wooden frame.

Low price and availability of material. Blocks can be formed from wheat, rye, flax, rice, and hay straw. The cost of a straw block is tens of 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 longitudinally oriented stems in relation to the future wall.

The energy consumption of a straw house is about 40 kWh/m2 per year, not particularly increasing even in the low temperatures of the Russian climate.

Reducing construction time and volume of work. The assembly of walls from straw blocks is carried out quickly, without any masonry mortar, and 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 environmental characteristics 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 infest them; when the humidity of the straw increases above 18–20%, putrefactive processes begin in it, destroying the straw blocks.

Both problems can be solved simultaneously by pressing the 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 increasing density, the straw block will absorb moisture worse.

It should be noted that increasing the density of the blocks will lead to an increase in their weight by two to three times, which will create some difficulties when building the wall. To combat insects, it is necessary to sprinkle them with slaked lime when laying blocks and use lime when preparing the plaster mixture.

DIY straw house

The wall fences of the house are made of straw bales, formed by a baler and tied with polypropylene cord - you need to carefully select them. Strapping made from 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 susceptible to rotting.

In some agricultural enterprises, straw is collected using roll balers; straw rolls, in principle, can be rolled out and pressed with a square baler, but it is better not to do this - the straw will become very wrinkled, which will affect its thermophysical characteristics.

Which straw is better? Rye or rice, and the straw of winter rye is most suitable, since its stem is denser, higher and, in addition, winter rye is harvested earlier than other grain crops. To build a house, you only need dry, seed-free and uncut straw - you should not form bales from wet straw, you must first dry it.

How to evaluate the characteristics of a straw block? A dry bale no more than a meter long and with a density no higher 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 immersing your fingers in the straw, you should not feel moisture, and when you bring them to your face, there should be no smell of rot.

Remove a few straw stems from the bale and bend them - brittle stems mean old and stale straw and will not be suitable for building. High-quality compressed bales are practically not deformed if they are lifted by the strapping; it is difficult to insert two fingers under the strapping cord; the blocks have similar sizes.

Like any other building, a thatched house needs a lightweight, but still foundation. 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, sheets of expanded polystyrene with a thickness of 100 mm or more will be needed - they are laid on the outside of the foundation and buried in the ground below its freezing depth.

It is important that the floor level in the house is lower than the position of the first row of straw bales - in case of water supply leaks, the walls with straw filling are guaranteed not to get wet.

Next, we determine the type of house construction - you can build a building with or 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 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 - the optimal one would be a hipped roof structure, the rafters of which are placed on a wooden mauerlat made of two boards laid on top of the wall and connected by crossbars in increments of one meter.

Roofing felt is laid on the pre-plastered end of the wall before installing the Mauerlat. The overhang of the roof cornice over 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 larger straw house is created similarly to the frame of panel houses. You can build a double-row frame and stack hay bales between two supporting posts.

Filling the wall areas between the frame posts with straw blocks is easier than building 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 stacked straw bales, laid in a checkerboard pattern (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 laying the fourth row. Also, metal rods are embedded in the base of the building in increments 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 to 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 onto them and clamping them with the Mauerlat beam using a threaded connection.

During frameless construction, adjacent walls are connected row to row with two 30 mm diameter pins curved in a U-shape. It is necessary to perform such fastening both along the external and internal lines 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 tying blocks before cutting; Several sharpened metal hooks for transporting straw bales.

The press consists of a pillar about a meter high, dug into the ground and securely fastened, on which a wooden beam-lever is movably attached.

Small grooves are cut out at the end of the lever, and a nylon rope is secured in them in the form of a loop. The block of straw to be trimmed is placed under this improvised press, clamped with a leg inserted into a loop and pulled with a plastic cord in a new place.

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, you need to lay a fine-mesh polymer mesh as additional protection against rodents entering the walls; between blocks with a density of less than 200 kg/m3, when forming each tier, kraft paper or cardboard is laid - it will interfere with convective heat transfer inside the wall.

In the process of laying rows in a frameless structure, there is no need to drive the blocks into place with significant force - the wooden guides that were previously placed along the edges of the walls may move.

Align the blocks in rows according to a string level stretched between the guides using a board of sufficient size and a heavy hammer.

The walls exposed under the roof structure should not only be secured with driven pins, but also tied together with plastic tapes in increments of one meter - wrapped at the bottom of a metal pin protruding from the foundation, tied and pulled around a wooden mauerlat at the end of the wall. Metal tape is not suitable for tying walls, because it hurts your hands and is quite stiff - difficult to pull.

In the openings for 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 extend beyond its boundaries - up to half of the adjacent straw blocks.

After the wall is erected, the boards of the window and door openings are secured with pins in bales - the pins are driven into the vertical boards inside the opening, the horizontal ones are fastened outside it.

Before fastening the opening box, it is necessary to overlap roofing felt or roofing felt under the boards, lay a plastic or metal reinforcement mesh on top of it, extending 300 mm beyond the edges of the opening, and secure it with 35 mm galvanized nails or 35 mm construction staples 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 attached with nylon thread or steel binding wire threaded through the straw.

To stitch 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 and, like a regular sewing needle, a thread or wire is threaded through it.

After assembling the walls, they need to be trimmed in those areas where the blocks especially protrude - 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. Water supply, heating and sewerage pipes should not be placed in a thatched wall, as they will cause moisture condensation and rotting.

The final stage of work on creating straw walls is applying two layers of plaster. A 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.

For less dense blocks, you will need to wait two to three weeks for the straw to settle and compact itself. Cement plaster cannot be used; it will prevent the passage of vapor-saturated air through the wall, or, to put it simply, it will prevent the wall from “breathing.” Clay-lime and cement-lime based plaster solutions with medium fat content are suitable.

Proportions of clay-lime solution: 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; lime milk (lime dough mixed with water to the consistency of milk).

The sifted cement and sand are mixed dry, then lime milk is added to the container with the mixture until the mixture of the required consistency is obtained.

To reinforce a straw wall on its outer and inner sides, you will need a metal or plastic mesh with a mesh size of no more than 30 mm. The first layer of plaster should be thick - about 25–40 mm, the leveling second layer should be 2–3 mm, it is made with a creamy plaster solution.

After the plaster has dried, the walls can be painted with water-dispersed paints - oil paints are not suitable, as they will act as a barrier to the air exchange of the walls.

Straw walls need to be plastered - attempts to avoid this by covering the straw bales with plasterboard, plastic or brick will create optimal conditions for rodents and insects, since there will be enough space between the straw wall and the cladding for their activity.

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 a vapor barrier on straw walls, this will lead to rotting of the straw.

Important! In the process of construction work on the construction of a straw house, it is imperative to observe the following fire safety rules: during the laying of walls, until they are completely covered with plaster and the perimeter is completely cleared of scattered straw, smoking, welding and other types of work with heating to high temperatures are strictly prohibited at the construction site temperatures, using an open flame and accompanied by sparks. Uncompressed straw is easily flammable, and the slightest spark is enough for it to ignite - this is not something to joke about!

During the construction of a thatched house, the construction site must be equipped with fire extinguishing means - barrels of water, charged and working fire extinguishers, and 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 catching fire (in the case of a frame straw house), since new straw blocks will cost much less than a new frame.

Straw housing construction undoubtedly has great prospects - in combination with eco-house technologies, cheap straw houses that consume a minimum amount of thermal energy in the cold season and self-air conditioning can give their owners more than just environmentally friendly housing. published website

If you have any questions on this topic, ask them to the experts and readers of our project.