Build a thatched house. A resident of Belarus is building a thatched house (25 photos). Disadvantages of straw houses

Under the right conditions, straw is a very good thermal insulation material that can be used in construction, photo 1.

Straw of wheat, rye and barley has high thermal properties. A house that is built of straw or straw blocks is called - eco house (ecological house).

Straw house construction - green building

A huge amount of straw is produced every year in the world, most of which is left in the fields or burned. This raw material can be used in construction, which would solve many social and economic problems in different countries of the world.

It is very important that straw is, first of all, a renewable raw material that is cheap and easy to convert into building material, and it is also easy to dispose of after many years of use: burn it or leave it to rot in the open air.

Photo 1. Straw and its collection

The practice of building houses from straw has been known for a long time and was applied in Ukraine, Canada, Holland, USA and other countries. For example, in the United States, intensive construction of straw houses began in the 19th century and is associated with the invention of the steam press for stacking straw into bales and blocks.

Nowadays, the technology of building thatched houses is being revived and intensively spread. In Western Europe, there is government support and interest in the construction of eco-houses. This program is designed to reduce overall energy consumption in the manufacture of building materials and the operation of low-rise housing.

Straw blocks can be used when | , as well as , photo 2... Such blocks can be used as the base of the floor in living quarters. A completed straw house is not much different from a house made from traditional building materials.

Photo 2. Ecohouse made of straw

Blocks of the following dimensions are usually made from straw (length × width × height):

480 × 480 × 350 mm;
900 × 470 × 350 mm (weight 15 ... 30 kg, relative humidity 10 ... 15%);
500 ... 1200 × 500 × 400 mm.

Important! Blocks must be rectangular and must be at least two heights in length. This condition must be observed for a good and strong bandaging of the blocks when laying them. Basically, the density of blocks is on average 120 kg / m 3, but it can also be in the following range of 100… 400 kg / m 3. Walls of a residential building made of bricks are 85% heavier than similar walls made of straw.

It is interesting! From one ton of straw, approximately 77 straw blocks can be obtained. To build a house with an area of 70 m 2, you need straw collected from a plot of 2 ... 4 hectares. A medium-sized residential building takes up to 700 straw blocks.

In terms of thermal technical characteristics, straw occupies a worthy place among heat-insulating materials:

Perlite, foam glass, vermiculite;
Silica or quartz airgel.
Polyurethane foam, polystyrene foam.
Straw.

Benefits of straw houses

Low cost of material and the house as a whole. On average, a box of a house with an area of 150 m 2 will cost up to $ 10 thousand.
High comfort of living in the house . The straw house "breathes", which creates a good indoor climate in winter and summer. Straw is highly hygroscopic, easily absorbs and releases excess moisture. With proper design, dampness and damage to the corner sections of the walls by fungus and mold is excluded.
Environmentally friendly material.
High durability of straw blocks (up to 100 ... 200 years and more), which is confirmed by history. The durability of straw is ensured by the presence of silica in its structure.
High construction speed. Four people can build a house box in 2 ... 3 days, and a complete house can be built in 2 ... 4 months.
Low labor intensity of construction works in comparison with traditional construction is about 100 times less when calculated per 1 m 2 of the total area of the building. No heavy equipment required.
High fire resistance. Straw under very tight compression and when plastering on both sides allows such a wall to withstand a fire load with a temperature of 1000 ° C for several hours.
High soundproofing of the walls.
Low coefficient of thermal conductivity - 0.12 W / m 2 K (for wood - 0.5 W / m 2 K). That is, the thermal conductivity of straw is 4 times lower than that of wood and 7 times lower than that of bricks. Minimum costs for heating and air conditioning (approximately 3 ... 4 times). It has been experimentally established that houses made of straw blocks consume 10 times less gas than in an ordinary house (heat loss is approximately 40 kWh / m2 per year).

Disadvantages of straw block houses

It is forbidden to carry out airtight cladding of the house, which will lead to the accumulation of moisture inside the walls and to rotting of the straw. Usually, such houses are plastered outside using plaster compounds with increased vapor permeability (lime, clay-lime, etc.).
It is necessary to follow the fire safety rules at a high level in the process of building a house.
At the construction stage, you should first plan the location of the hanging furniture in order to install additional beams. A clay wall without additional reinforcement cannot withstand hanging furniture (low material density).
If the construction technology is not followed, insects and mice can start in the straw walls, and with a straw moisture content of 18 ... 20% or more, the straw begins to rot. The straw should be pressed as much as possible to a density of 250 ... 300 kg / m 3 and an additional mesh should be installed with a thick layer of plaster on it.

Ecohouse construction technology

Consider briefly the myths of most people when they are faced with the technology of building houses from straw.

Myths and doubts

The straw is an ideal place for life and breeding of rodents and insects.

Rodents and insects do not settle in dense, compressed straw. Also, the walls of straw from the outside are finished with a metal mesh (chain-link, expanded metal, woven, etc.), and then they are plastered with a thick layer of clay. Rodents never eat rye straw. If the construction technology is observed, the moisture content of the straw inside the wall is 3 ... 5%. In such dry straw, insects do not start and do not reproduce, they need a moisture content of more than 20%.

Straw is a very dangerous material for construction, as it is a highly flammable material.

As noted above, compressed straw and plastered on all sides is a very resistant material to fire and meets the requirements of fire safety standards.

Straw is not a durable material .

History shows that houses that were built 100 ... 200 years ago have been perfectly preserved to this day in many countries of the world: Germany, Holland, England, France, USA and Canada.

4. The wall of such a house is easy to destroy.

In fact, a straw block wall is strong enough. So, when testing a Canadian company, a wall of straw with external and external plaster and dimensions: 2.5 m (width), 3.5 m (height) and 0.5 m (thickness) is able to withstand a vertical load of 8000 kgf and a side load of 350 kgf. It has been found that thatched walls and roofs are able to withstand the following loads:

snow loads - 293 kgf / m 2;

wind loads - 78 kgf / m 2;

constant loads - 234 kgf / m 2.

Types of technologies for building a house from straw

The technology of building houses from straw is divided into several types:

frame thatch house (the supporting element of the house is a wooden frame, and the space between the frame elements is filled with straw), photo 3;
frameless thatched house (the supporting element of such a house is not a wooden frame, but walls made of straw blocks).

Photo 3. Frame house with straw block walls

The main stages of construction of a frame thatched house

Carry out the construction of the foundation.

A concrete foundation is poured or built with natural stone, taking into account the load on the foundation from the frame, walls and roof The choice of the type of foundation depends on local conditions. Usually strip and pile foundations are used.

The frame of the house is being erected from wood. Usually, the frame racks are made of two-branch, from a bar.
Straw blocks are inserted between the posts. Additional fastening of blocks to each other is performed when installing every fourth row of blocks using:

bamboo or metal rods;
thin wooden poles.

Sometimes the blocks are connected to each other with a lime mortar.

The walls are leveled with a hand saw or other cutting tool.
The walls are sheathed with plasterboard, OSB boards or plastered. A metal mesh is packed in front of the plaster for good adhesion of straw and plaster. Usually, the outside and inside of the walls should be plastered with a thickness of at least 50 mm. A layer of plaster prevents the straw from getting wet and wet, rodents from getting inside and the straw from rotting. It is best to plaster thatched walls, as this will increase their fire resistance.
For coating blocks and plaster of straw walls, the following composition of clay-lime mortar (by weight) can be used:

10 parts of clay with a consistency that meets the yield point;
4 pieces of lime dough;
30 ... 40 parts of fine quartz sand.

Or you can use a cement-lime mortar (by weight):

Part 1 - Portland cement;
3 ... 4 parts - fine quartz sand;
4 parts milk of lime.

The first layer of plaster should be 25 ... 40 mm thick, and the second (leveling) layer - 2 ... 3 mm.

The main stages of construction of a frameless thatched house

The main stages of construction are almost the same as in the construction of a frame house, with the exception of the frame device, photo 4... Such a house is built only from straw blocks, by analogy with a brick wall.

To support the rafter structures, a distribution belt made of thick boards is made of straw blocks along the top of the walls.

The roof in such a house should be as light and simple as possible. Two types of straw blocks are used for construction:

dry straw, pressed into blocks of various sizes, photo 5;
compressed straw blocks treated (coated) with clay mortar, photo 5.

Photo 4. Construction of a frameless thatched house

Photo 5. Straw blocks: regular (left) and coated with clay mortar (right)

The structure of a frame house is much stronger than a frameless one, but the cost is more expensive due to the use of more wood. Framed thatched houses can be designed and built with complex structures with different types of roofs, which cannot be done using frameless technology.

The disadvantages are obvious

1 Risk of rotting in high humidity

Straw with a moisture content of more than 20% begins to mold, the stems rot and collapse, so it is so important to keep the straw blocks dry before starting construction, lay them dry and quickly cover them with plaster.

It also follows from this that thatched walls cannot be left open... At the same time, the choice of coatings is also limited:

cement-sand plaster
clay-sand plaster
gypsum plaster
gypsum sheets
wooden panels

The risk of mold growth exists for both unplastered and poorly made walls.
In areas with a constant humid climate, you will need high-quality vapor barrier on the inner surfaces of the outer walls.
The house will be protected from heavy rainfall by wide overhangs of the roof.

2 Fire

Plastered pressed straw blocks have high fire resistance, they are officially assigned a very high. A properly protected straw wall is superior to a wooden one in terms of fire safety. But straw scattered around the construction site can easily cause a fire... You need to be especially careful with straw in attics, attics, near fireplaces.

In confirmation - the story of a woman whose house burned down during the construction phase.

“A house for permanent residence was under construction (autumn 2005). I bought the plot with a ready-made basement floor. The frame was fixed to the foundation with 14x220 anchors. The blocks were tied with two simple twines; a lot of gutting was done during the installation ... The outer wall was covered with DSP, and the inner ones were sewn up with a board at intervals.

In the photo you can see to what stage the house was built until it burned down (on the second floor they managed to make a rough floor and interior partitions). At this stage, builders began to lay glass insulation on the foundation on the 1st floor, heating it with a blowtorch (April 2006). According to them, the windows on the second floor were open. After a while, it began to smoke under the skin and floor. They began to blow up, flood, but could not, the fire spread very quickly and burned down the whole house. There are many versions, but I think there was a draft of hot air and, most importantly, a violation of fire safety techniques ... "

Prevention measures:

no smoking on the construction site
promptly clean up scattered straw
always have a fire extinguisher on hand
do not use open sources of fire until the walls are plastered
use tightly compressed straw blocks
after laying the blocks, plaster them outside, and then inside the house, before proceeding with the interior decoration.

3 Rodents

“So the mice will eat it” is a very common statement about straw houses. Why is it so common? Because mice can actually settle in straw in search of food and warmth. True, not in any straw, and not entirely in straw :) It is inconvenient for mice to settle directly in straw blocks - they are prickly, but in the voids between the block and, for example, a gypsum plasterboard - they may well.

By the way, rodents are not the only small pests that can help you pull your home through straws :) There are also birds and insects that can also choose straw as their habitat.

Prevention measures: use rye or rice straw for insulation (mice do not eat it and do not settle in it), isolate all possible access routes to the straw.

Disadvantages little-mentioned, but real-life

4 Limitations in design

When using a supporting frame, design restrictions are small, but there are, and they primarily relate to the number, location, width and height of openings.

5 Thick walls

Makes walls quite thick. One of the difficulties with walls of this thickness is the need to expand the foundation and increase the roof area... In homes with thinner walls, creating the exact same usable interior space requires fewer resources.

6 Few typical projects

Unlike houses built using other technologies, there is a clear lack of standard construction schemes from straw blocks. This means that the development of a project for the construction of a thatched house will most likely have to be ordered individually, and you will have to look for understanding architects, designers and builders.

In some countries, there are still no building codes (in Belarus it is regulated by SNIP, in the Russian Federation and Ukraine, it seems, there are also).

7 Time and money

You need to immediately have a certain amount on hand in order to quickly solve "must-have tasks". I will cite one dialogue from the forum that illustrates this point well.

-… one BUT: if I put up a log house and I run out of money - I can live in it unfinished, but a thatched house requires both external and internal finishing, and immediately.
- The cost of the minimum decoration for life in the house is so insignificant that it does not deserve a separate discussion. If there is money for the frame, roof and windows, then there will be crumbs for plastering.
- Something tells me that it will be at least $ 5 per square, - and there are a lot of squares in the house!
- Necessarily! Not less than 5! If you don't put the pens yourself, but walk and poke your finger - here it is uneven, grease there ...

8 Time and money - 2

We have a suitable straw closer to August, and if there is not enough money, then we may not have time to do everything before winter. And in winter, the outer walls cannot be plastered. Therefore, there is a prospect under the roof of an unfinished house or farm building on the site, and after it - and risk No. 1.

9 "Pointing Finger"

Due to the fact that the technology of construction from straw blocks is not yet very widespread, it will be necessary to monitor the progress of work much more and more carefully compared to construction from "traditional" materials: so that builders do not smoke, do not work with a burner, and so that fertilizers are nearby did not turn out to be with straw (for example, ammonium nitrate - in contact with sawdust or straw, spontaneous combustion is possible), and so that children with matches do not appear nearby ...

P.S. Disadvantages of thatched houses with a load-bearing frame

You may have already heard that a thatched house can be built wireframe and frameless... To be honest, while I have little idea of the process with this, however, people call the disadvantages of straw construction with a supporting frame, so we will mark them just for show. So, this is an additional expenditure of time, money, labor, materials to create a supporting system, when the blocks themselves could support the weight of the roof, as well as the need to create a foundation that carries the weight of the blocks and concentrated loads from the vertical struts.

Don't know the global ones!
Do you know more about disadvantages and risks? Please share!

Read soon:

Thatch House Myths
"Straw" superstitions

Recently I came across an interesting video material. While watching a video on how to build a house from a bar, I noticed another story - about how to build a house from straw with your own hands. And after looking, I decided to write about it.

The video was filmed by the settlers of the Ark.
It turns out that the cost of building such a frame house made of clay and straw is not very high. The technology is also not very complicated. The house turns out to be warm. In the plot itself, it is shown how to build a frame house from clay and straw, the terms of work, the price of construction, the technology of pressing clay with straw are told. The video is definitely worth watching, even just for the sake of your own development. And suddenly, it will come in handy in life!

The return to partially forgotten building technologies is associated with the tendency to use natural materials. They give homes a natural feel 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 indoor climate and relative simplicity.

The adobe house. What it is?

Analogs 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 whole adobe cities. The improvement of building technologies has led to the widespread distribution of clay buildings in the territory of central Europe and modern Russia. Correctly 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" is the ability to give the walls an arbitrary shape and adapt to home furnishings. Numerous recesses, baths and smooth transitions strikingly distinguish the earthen structures from brick and other block-cement structures.

Old technologies are rarely applied as they are, as the performance of modern homes is enhanced by the use of modern additives. The natural fire-fighting properties of clay, which are prone to baking at elevated temperatures, are improved with the introduction of components that increase the strength characteristics.
Adobe construction technology

1. Materials that should be stocked up in advance:

wooden boards and beams for the construction of the frame of the walls and roof;
clay;
sand;
straw;
water (well or centralized water supply).

Additional materials that will come in handy during the preparation and finishing stages include:

gravel - for preparing bedding under the foundation;
material for the manufacture of solid or brick foundations;
flat wooden planks for upholstery of the walls of the house;
wooden (metal) formwork or mold for making blocks.

Although the house will be made of 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 bottom of the walls.

The place for construction should be chosen away from lowlands and an outlet to the surface of groundwater. The optimal location of the clay house is on a hill.

To get the most durable structure suitable for our latitudes, it is better to make walls by pouring mortar into the formwork. You can also use clay blocks, which are stacked in a similar way to classic block structures.

A significant reduction in the cost of construction is achieved by self-extracting clay on your site. Small quantities of straw are cheap, and the largest costs will be in the purchase of sand and lumber.

The straw must be dry and free from rot. It is best to buy it immediately after the harvest season, and then leave it in a dry and ventilated area over the winter.

2. Preparation of the solution

Many authors advise not to use 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 suitable composition should not split or flatten strongly when dropped.

To prepare the solution, you can use a concrete mixer or a flat base with the edges bent upward (stir the solution with your feet). The clay is crushed to a finely dispersed state, after which sand and water are added to it. The latter should not be too much so that the mixture retains a high-viscosity 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 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. Above 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 time to dry. When self-building, the wall usually "grows" by 10-15 cm in one day's cycle.

Outside, the walls are covered with a crate made of straw or reed - they create an additional heat-insulating layer. The lathing is fastened with a thin layer, which is pressed against the wall with wooden flat strips (nailed to wooden supports). Outside, the crate is covered with clay or lime plaster.

3. Roof made of thatch and clay

Tied bundles of straw are laid on top of the roof frame, upholstered with planks, which are then leveled (the rope that holds them together is cut). The straw is fixed in the same way as the lathing on the wall - with wooden slats. After covering the roof, you can start coating it with clay-sand mortar.

The process is carried out from the lower edges of the roof to the ridge. After hardening, the coating will not allow moisture to pass through, however, it will allow the room to “breathe” and maintain the humidity at the optimal level of 50-55%.

Feature: the roof should be poured alternately and evenly on both slopes to avoid skewing.

4. Decoration of 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 does part of this), cattle manure was widely used in the past. The same mortar was used to plaster the walls of the premises, which received the name "hut". The main disadvantage of such houses is the abundance of insects in the walls.

Nowadays, natural chaff and fire are used to increase the strength. A couple of centuries ago, it was difficult to get them, but now they are waste of plant processing.

type of adobe house

An increase in strength and a decrease in shrinkage during drying is increased by the addition of crushed stone or expanded clay. Sand is an auxiliary element. To increase the speed of hardening, cement or lime can be added to the composition of the clay-sand mortar. Their additives are used in construction in wet weather, with the aim of reducing the risk of wetting the wall material while still wet.

Casein, starch and water 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 ecological properties of the house, but it will improve the performance characteristics.

To protect the house from rodents, you need to provide for the presence of a thin metal mesh under the crate.
Features of the care of thatched houses

Fire safety is a separate item in the operation of buildings. Clay houses, which are coated with external and internal surfaces with clay or lime mortar, are less prone to destruction in case of fire than ordinary ones. When a flame occurs, the straw in the walls does not ignite, since the air access to it is closed by a layer of clay.

house wall made of clay and straw

Despite the high fire resistance of the walls of adobe houses, the wooden parts of the roof do not have it. To reduce the likelihood of fire, wood should be treated with fire retardants. They do not provide absolute protection against fire, however, they are very effective if the application technology is followed.

Construction companies engaged in the construction of houses from clay and straw, assure about 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 ignore the advice to use lime plaster, which will clog the walls for moisture and inhibit the development of insects.

Consider the location of the oven and bathroom before building your home. Reflective screens should be placed in places of contact with heated surfaces, and waterproofing should be done in damp places.
An adobe house: the pros and cons of the structure

Advantages of adobe buildings:

clean and healthy "atmosphere";
indoors it is 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 author's personal experience of building, see the video:

on the materials of the Internet

Peculiarities

- Availability. Not all regions have cereal fields. At the same time, due to the large volume, delivery of straw blocks even over 100 km can increase their cost several times. Therefore, in the absence of straw in your region and the need to carry it from afar, it may be worth thinking about other options for organic (fire, sawdust, algae, ecowool, etc.) or synthetic insulation.

- Rodents and insects. Dry pressed straw is not a material that attracts insects (neither for life, nor for food). The only exception can be termites, but for most regions of Eurasia such a problem is excluded. In relation to rodents, straw houses do not differ from houses of other designs. That is, mice do not show interest in straw as a food product (they can only be attracted by the grain remaining in the straw), but they can settle in voids and leaks: between bales, frame elements, sheathing and interior decoration of premises, cable ducts etc. The methods of protection against rodents are the same as in houses of other structures: metal nets along the bottom of the wall (and the floor, in the case of a columnar foundation), reduction of possible voids (plaster, careful tamping of straw), the presence of a cat in the house.

- Types of straw. Any straw from grain (and not only), hay, as well as reeds / cattails are suitable for construction. Traditionally, preference is given to rye straw, but this is due to no less danger from rodents, as some straw construction “gurus” mistakenly declare (mice can settle in any straw if there is free space), and with high stiffness and longer stems of rye, which makes the finished bales stronger and denser (in general, other things being equal, it is better to choose straw with longer stems). Rice straw, in turn, has increased rigidity and resistance to moisture, but it is available in very few regions. Hay can be used instead of straw, but it is necessary to take into account the lower rigidity and structuredness of the bales, low strength, high nutritional value of hay (it can attract rodents), as well as the potential for allergenicity (since the composition of forbs mown at the time of flowering can be very specific). Reed / cattail stalks are a good material with interesting characteristics (strength, resistance to moisture), however, their harvesting on an industrial scale is difficult (although special combines exist), which does not allow the use of this material in large quantities (except for small mats and decorative panels).

- The quality of the bales. The best for construction are bales with a density of 90-150 kg / m3. At a lower density, the bale becomes too loose and requires additional pressing after being placed in the frame. With a higher density, the thermal conductivity of the material increases, but the requirements for additional pressing of the laid bales decrease. However, for standard bales, undersight is much more common than oversales, due to the desire of farmers to reduce the load on the balers. Therefore, when buying straw, it is better to agree in advance (before harvesting) with the supplier on the required size and density of the bales. It is also necessary that the straw is dry during pressing and does not remain on the field for a long time. Multiple transport (loading-loading) negatively affects the density of the bales. Buying non-seasonal straw (winter-spring) requires special attention to its quality.

- Bale dimensions and frame. In straw construction, they traditionally try to adjust the pitch of the frame racks to the length of the straw block: usually 850-1000 mm (except for frames taken out from the plane of the wall, where the bales are laid with overlapping joints and is not related to the pitch of the frame racks). This makes it possible to simplify the stacking of blocks, to minimize their trimming, and also improves the thermal insulation performance of the wall (the number of cracks at the joints of the bales decreases and the overall density of the wall increases). To do this, the step of the frame racks is made 5 cm less than the average length of the bale, which is laid “by the spine” with additional compaction. Therefore, it is advisable to agree with the supplier on the size of the bales before starting the construction of the frame (or look for bales for an already built frame, which can be more difficult). Window openings are also made multiples of the length of the block and are additionally reinforced (compressed bales can exert significant pressure on the window frame). It is better to install window boxes (finally fix) after the walls are completely filled with bales and pressed to avoid deformations and distortions of the box.

- Heat capacity. Straw, like wood, consists of cellulose and has a comparable heat capacity. However, the volumetric weight of straw bales is small, as a result of which the final heat capacity of the erected walls is lower than that of a house made of timber / logs, but higher than that of frame houses insulated with synthetic materials. For permanent residences, it is recommended to increase the heat capacity by using thick internal plaster, floor screed, internal walls (made of brick, adobe, concrete) or a massive stone stove.

- Mowing a straw wall. In most cases, after placing the bales, it is recommended to trim / level the straw wall (in the case of Larsen stands, the wall is aligned flush with the outer frame stands). This improves the geometry of the wall, simplifies further plastering and / or fastening of ventilation. facade. It is more convenient and quicker to use a brush cutter with a long blade for cutting, but a trimmer (with a disc instead of a line) or a chain saw is also suitable. Chopped straw is best used in plasters to increase their strength and ductility. At this stage, special attention should be paid to fire safety due to the large amount of light, combustible material on the construction site.

- Plasters. Covering thatched walls with quality plaster is the most effective way to increase the fire resistance of walls and reduce unwanted infiltration (blowing). Natural vapor-permeable plasters (based on lime and clay) help to regulate the level of humidity in the room and improve the microclimate of the house as a whole. However, the selection of the correct composition and the optimal application method can be a complex task, requiring the study of locally available materials (clay, lime, sand, different types of fibers) and the organization of trial "batches" with different compositions and proportions of components.
Use in the composition of cement is possible, but in limited quantities and only with careful selection of the remaining components of the plaster mixture - to maintain sufficient vapor permeability of the coating. Premixed plasters (eg gypsum-based) can be used, but are usually too expensive for the required layer thickness (2-5 cm for outdoor use).
The traditional method of plastering (based on clay and / or lime) involves a first liquid layer (the consistency of liquid sour cream), applied under pressure (either mechanically or rubbed in by hand) to better penetrate the surface layer of straw (on top of this base layer, if necessary, can the plaster mesh should be fixed for better fixation of the base layer). The main layer (usually 2-5 cm thick) is made with a large amount of fiber (chopped straw, sawdust, fire or synthetic fibers) and also with the addition of natural plasticizers (for example, flour or flour paste) to increase strength and reduce cracking (the correct composition of this layer is most important!). The finishing layer performs a decorative and protective function, is often applied over a plaster mesh (or natural burlap) and may contain fine fibers (sawdust, cattail fluff), plasticizers, various pigments and additives (oils, wax, PVA, casein, etc.) ... Often on top of the finishing layer, to increase its strength, additional liquid coatings with different compositions are applied (based on flour paste, soap, linseed oil, PVA, casein, siloxane, etc.). It is important to take into account that many additives (for example, impregnation with linseed oil and wax) significantly reduce the vapor permeability of walls and should be used with caution. Any natural coatings can be polished with special attachments (for example, diamond and stone discs on a polishing machine), which also increases their strength and moisture resistance.
The places where the plaster layer adjoins the wooden elements (especially to the supporting frame) must be protected by an additional layer (s) of plaster nets. Also, special attention should be paid to the corners of the walls, places of abutment of window and door frames, joints of floors. All wooden elements passing through the outer walls to the outside must be additionally wrapped in felt tape (or other material) to prevent blowing.

- Wall protection. Thatched walls with clay plaster may require additional weather protection, as clay without a protective layer (for example, based on siloxane) is easily washed away by rain. Lime compositions are more resistant, but they also require protection from oblique rain (long roof overhangs or adjoining terraces). The cardinal solution is to use vent. facade on top of a plastered wall. In this case, it is desirable to provide for the possibility of simple dismantling of the facade for inspection of the plaster.
In the absence of a plaster layer or its poor quality, it is important to additionally protect the wall from blowing and fire. For this, various windproof membranes and non-combustible board materials (CSP, MDVP, etc.) are used. Vent. the facade is required in this case.

- Non-frame buildings. Thatched blocks can be used not only in frame buildings, but also to insulate walls of any other structure (brick, concrete, adobe, etc.). At the same time, it is important to ensure the rigidity and uniformity of the straw insulation - either using a thin wooden frame, or using strong nets and tightening straps (to press the insulation against the main wall). The issue of protecting such a wall from waterlogging and the location of the dew point should also be given special attention.

- Vapor permeability. Thatched blocks have high vapor permeability, however, for their better preservation and protection of the wall from waterlogging, the general rule must be observed: the vapor permeability of the wall should increase from the inside out. That is, the vapor permeability of the interior should be lower than that of the exterior. This is achieved by the correct composition of the plasters (or type of materials) and the selection of the thickness of the layers. For the most important areas where the water vapor pressure is at its highest (a thatched roof or a ceiling under a cold attic), it is advisable to limit the vapor permeability of the interior decoration (for example, use a vapor barrier or a low vapor permeability topcoat).
Convective air currents can form inside thatched walls, increasing heat loss. To reduce them, it is recommended to lay cardboard or kraft paper (or other vapor-permeable material) in a continuous layer over the blocks at the stage of placing them in the frame - either after each layer of bales, or after several layers.

- Wiring. The placement of all wires in contact with flammable materials (wood, unplastered straw) is mandatory in metal pipes or metal corrugation. Placing wiring inside (along) thatched walls is highly undesirable. Usually, the wiring is done in the plaster array, along the inner walls, behind the clean ceiling, in the floor screed, in cable ducts, etc.

- Shelves and attachments. Light objects (paintings, clocks, decorative elements, photo frames, etc.) can be immediately attached to a plastered straw wall with a sufficient thickness of plaster (5 cm or more), although this is not desirable. In the case of wall decoration with slab materials, fastening of more massive objects is also possible. The heaviest equipment and items (massive shelves, wall cabinets, boilers, gas boilers, etc.) are best attached to the inner walls or to reinforcing linings / jibs pre-installed in the frame. In general, it is better to leave the outer walls of the house as open as possible to maintain normal air circulation along them (reducing the risk of surface hypothermia and moisture condensation).

- Exterior of the house. The use of straw as wall material does not impose any restrictions on the design of the house. When using plasters, it is possible to achieve both ideal smoothness of walls and precise angles, as well as traditional "soft" forms characteristic of natural construction (adobe houses). Using vent. facade allows you to make an external finish of any material, including imitation of brickwork or clinker, if necessary.

- Frameless construction. When building small one-story buildings (for example, baths, sheds, guest houses), it is possible to build from standard straw blocks without a supporting frame. However, this technology requires a very high quality of bales (high density), their reliable connection to each other (wooden stakes, strapping tape), vertical compression of the wall (and its fixation in a compressed state), as well as a lot of experience and high skills of builders. In reality, this method should only be used when there is a high wood deficit or when you are fully confident in your knowledge and skills. Frameless multi-storey construction is possible when using large blocks (so-called jumbo-bales), but this method also has a number of features.

- Jumbo-bales. Large straw blocks have a size (on average) 900 * 1200 * 2500 mm and have a very high density (200-400 kg / m3). The strength of such blocks allows you to very quickly (in the presence of a ready-made foundation, the construction of the walls of the house can be completed in just a few days) to build frameless buildings of several floors from them. The thermal conductivity of such blocks is higher (due to the high density), but this is compensated by the significantly greater wall thickness (1200 mm). Jumbo-bales are a promising building material, but they require a wide foundation and a tractor or loader to lift the blocks. Also a disadvantage is the large area of the house, occupied by the outer walls.

- Wall thickness. The use of standard straw bales determines the minimum wall thickness of a house at 400-600 mm, which requires a wide foundation (more precisely, a wide top shelf of the foundation, or complicating the structure of the frame, in the case of a pile / column foundation with a wooden grillage). However, it is important to take into account that when building any energy efficient house with comparable thermal insulation characteristics, the final thickness of the outer walls will not differ significantly from that of a thatched house.

- Official approvals. Straw blocks as thermal insulation material have regulatory documents in many European countries, in the USA, Canada and Australia. Numerous independent tests have been carried out for thermal conductivity, flammability and humidity. Unfortunately, on the territory of the countries of the former USSR, straw blocks do not have official regulatory documents and are not included in SNiP. However, this does not prevent the construction of such buildings officially, since thatched houses, in fact, are frame buildings with organic insulation. Like all frame buildings, they are considered "combustible" and belong to the IV class of fire resistance. When drawing up documentation for the construction of a house, it is advisable to design a thatched house as an ordinary frame house (do not specifically indicate that straw will be the insulation). With this design, no special problems with documentation and construction usually arise.

Terminology
The most valuable thing in a person's life is his health. Everyone understands that it is impossible without a healthy lifestyle. Many environmental factors affect human health. What we eat, what we drive, where we live are all crucial.
A healthy lifestyle is impossible in an environment filled with harmful substances. Therefore, in the pursuit of health, we come to the need to use environmentally friendly building materials. Unfortunately, many of those who prioritize a healthy lifestyle do not see the difference between environmentally friendly and sustainable materials.
Environmentally friendly materials are called materials that do not have a detrimental effect on the environment. But only those materials that do not cause any harm to the environment at all can be called absolutely environmentally friendly.

On the need to use straw
The use of environmentally friendly materials is not a sufficient measure to preserve the environment. The fact is that when creating such materials, technologies that harm nature are often used. For example, when using different devices and units, the demand for electricity increases, the production of which can be associated with "dirty" processes. In addition, the amount of resources required to sustain production increases. This includes the creation and use of lubricants, spare parts, as well as waste from related production processes.
Brick, mineral wool, natural stone and other environmentally friendly building materials require a lot of energy and resources to manufacture. The use of wood, as one of the most environmentally friendly materials, leads to the rapid reduction of forests on the planet. Therefore, using wood is not a sustainable approach to construction.

Combining convenience and environmental friendliness
The logical conclusion is to reduce the amount of wood in the construction of buildings to the minimum possible. This issue has already been partially resolved - "frame" construction is gaining more and more popularity. The share of wood used in this technology is only about 15% of the total wall material.
(Compare this with a house made of logs, in which wood makes up 100% of the material. To build one house with an area of 150 square meters, you need to cut down a quarter hectare of forest. For reference: it takes 30-50 years to grow a tree suitable for cutting six-meter boards).
The walls of buildings with frame technology consist of wooden "ribs", the space between which is filled with some kind of insulation. Most often it is mineral wool or expanded polystyrene, better known as polystyrene foam. And he and the other insulation can not be called environmentally friendly. During operation, they can emit harmful substances into the atmosphere. In addition, the installation of mineral wool insulation is fraught with the risk of damage to the skin and mucous membranes of a person.
Perhaps the only insulating material that has the right to be called environmentally friendly is ordinary straw. It is an annually renewable resource. Moreover, it appears as a by-product in the cultivation of cereals.
Therefore, there is no need to create a separate production facility for straw. After all, straw remains on the field after harvesting - wheat, rye and the like. You just need to collect it.
In the production of wall panels, it is most advisable to use rye straw. It is not suitable for the household - due to its rigidity, it is not even suitable for flooring in animal housing. Often times, it just stays rotting in the fields. In addition to this, the straw has excellent sound and thermal insulation qualities. It is three times more effective than pine wood and 10 times more effective than brick.
Consequently, rye straw, as a raw material for construction, has three key advantages: annual renewability (remains in the fields), lack of energy-intensive production (costs only for collecting straw) and fiber structure (thermal insulation). Thanks to these advantages, straw insulation is out of competition in terms of environmental friendliness compared to other materials.

History reference
People have been using straw to build houses for thousands of years. The first mentions of thatched houses (in surviving sources) have come down to us from ancient Egypt (about 5000 BC). Since then, the technology of straw housing construction has come a long way from adobe houses to multi-storey buildings with straw insulation.
Initially, these were walls made of straw, covered with clay for strength and weather resistance. Then there were houses built of bricks made from a mixture of straw, clay, sand, earth and water. Later, straw pressing was invented, which made it possible to erect the walls of one-story buildings from straw briquettes, and then cover them with plaster. To date, the development of technology has come down to the creation of wall panels with straw inside, ready to be installed and formed walls.
Today straw technology is used in many areas of Eurasia (from Kuban to Great Britain), North America (USA, Canada) and others.

Not afraid of water or teeth
The straw, which is used as insulation, does not rot. Firstly, the rye, which has not yet been harvested, is washed by the rains and then dried by the wind. Secondly, it is collected only in dry, sunny weather. Thirdly, after being pressed into the wall panel, the straw is plastered on both sides with a layer of moisture-proof material: clay or gypsum. This plaster protects from moisture, but at the same time it is perfectly vapor permeable. Thanks to this, the straw insulation is highly durable.
In addition, rodents do not grow in rye straw. There are also several reasons for this. The first is that the straw goes to the production of panels after harvest. They are simply dry stems left over after threshing, freed from leaves, inflorescences and seeds. There is nothing for rodents to eat in this straw. The second is that the straw contains a substance called lignin, which rodents do not like very much. The third is rye straw so hard and prickly that it cuts the skin. Therefore, straw is not suitable for living either - it is uncomfortable to sleep on it.
In addition to this, straw contains 2-3 times more silica than wood. This makes it more durable and resistant to fungal attack.

Brief description of technology
The straw is collected from the field using an automatic baler. It leaves behind bales that the workers manually load onto the tractor body. After that, the straw is delivered to the edge of the field, where it is transferred to a truck that carries the straw for the production of panels.
At this time, the assembly of the frame for the panels is in progress in the workshop. Using pre-prepared boards (dried and sanded), frames of future panels are formed. Then the straw is pressed into the assembled frames to a density of 140 kg / m3. With this degree of compaction, the straw becomes a completely non-combustible material.

When creating one standard wall panel 1.25 m wide, 2.5 m high and 0.42 m thick, 15 rectangular bales of 30 * 50 * 80 cm are required. Taking into account the weight of the dried wood, the finished panel weighs 230 kg. The plastered panel weighs almost 600 kg.

The last step in creating a wall panel is to cover the front sides of the panel with plaster. At the same stage, cable and ventilation ducts are laid in the plane of the wall. As a result, a finished panel comes out of the production line, suitable for installation of walls or ceilings on a construction site.
Such panels allow building houses up to 3 stories high. If, when assembling the panel, add metal to the wood, the number of storeys of the building with straw insulation can be increased to 5 floors. Such houses are very common, for example, in Germany.
A building made from such wall panels can withstand a magnitude 10 earthquake.

Assembling a finished house
Wall panels assembled using the latest advances in straw construction have such important qualities as durability and reliability. They are carriers in themselves. In addition, the technology allows you to customize production for the production of panels of various formats.
Thanks to the proven technology, the finished panels are easy to install, and also have a primary finish. You can immediately attach decorative elements and light furniture to the side of the panel facing the inside of the house.
The technology allows assembling the house at any time of the year, observing the only condition - dry weather.

Water and fire are not afraid
The plaster used to cover the straw consists only of natural materials. Its main components are gypsum or clay, which have the same properties. Other components of the plaster serve to give it rigidity - salt, lime, or are added as heat-insulating fillers: chopped straw, sawdust, sand, vermiculite, expanded clay.
In addition, the clay additionally preserves the entire structure. They say that thanks to this very property, several decades after the construction, dismantling such a house, a tree that has not been spoiled by time is found in the thickness of the wall.
But clay has another unique property: it maintains ideal humidity in the room, absorbing excess moisture or giving it back if necessary.
The fire safety class of the wall panel is K0 (30). This means that the plastered panel will withstand exposure to open fire for 30 minutes. Only then will the straw insulation inside the panel heat up and begin to smolder. The straw will stop smoldering without further heating.
The humidity inside a panel house with thatched insulation is maintained within the range of 40 to 60%. This indicator is comfortable for a person in the warm season. Consequently, the humidity inside such a house will be comfortable all year round.

It's easier today
For a long time, construction using straw was very time consuming. Collecting straw, laying in walls, covering with clay - all this required a lot of time and effort on the part of the builder. Forming briquettes from straw using a baler right on the field did not save the builder from manually laying briquettes to form the walls, as well as from plastering. Now - with the presses in the shop - the panel assembly process has been greatly simplified and accelerated.

Thatch house building is the most environmentally friendly.
A home built using thatch has many positive aspects. Straw insulation does not require high energy consumption when creating. Straw does not create any inconvenience during installation, like mineral wool insulation. It does not emit harmful substances and does not serve as a pollutant remaining after construction.
In addition, straw has excellent sound and heat insulation. It is the best foundation for creating a passive, self-contained home. It allows you to significantly, up to 50%, reduce energy consumption for maintaining the temperature. According to statistics, 27% of the energy generated in the world is spent on space heating in cold seasons and cooling in warm seasons.
Considering all the listed features of straw insulation, we can conclude that this is an absolutely biopositive material. Its extraction, production, use and disposal do not cause any harm to the environment.

To keep up with the times
A house that uses rye straw for insulation is not just environmentally friendly. Such a house will be the most energy efficient and environmentally friendly of all. By building such houses, we protect nature from pollution. Thanks to the development of technology, today's house with thatched insulation has nothing to do with the hut, which crumbled from the wolf's breath in the famous fairy tale.
Life goes on, technology develops, straw grows, houses with straw insulation stand and delight their owners. Realizing the value of the environment, you need to arm yourself with the fruits of technology development and keep up with the times.