Excellent do-it-yourself wood chip and sawdust concrete floors

In general, initially I wanted wooden floors along the joists, I even adjusted the width of the house (6.2 m) to the length of a standard board, and now I slightly regret it, well, at least I needed 7 m (not 6.2 m x 7 m as now, but 7 x 7 m ) to get more space in the hallway and bathroom for my layout. But what’s done is done, and a lesson for me - before starting construction, you need to spend a lot of time studying all construction technologies and drawing up your own project for a compact house, without involving third parties, i.e. exclusively with your own hands. It could be 2 or 3 years, but the rush here is definitely unnecessary.

It’s good, however, that I learned in time about the designs of one-story houses with an open ceiling from the Belarusian architect Vladimir Chernushevich, which provides many advantages and opportunities. But I only learned about sawdust concrete, chip concrete (wood concrete) when I started building the walls of my house. The fact is that I did not consider concrete floors for my project at all, despite their obvious advantages over wooden ones - the absence of rotting and the trampoline effect, durability, and cost-effectiveness (in the south, wood is not cheap). I just didn’t want to mess around with heavy concrete - no joke, transferring 3 cubes. I won’t pretend to be Hercules, it’s stressful for me.

Advantages and disadvantages

Arbolite has a huge number of advantages compared to other building materials.

• Environmental friendliness of raw materials. It is made mainly from natural ingredients.
• High fire resistance. Despite the fact that wood concrete mainly consists of wood waste, it is not flammable.
• Good vapor permeability. This property allows buildings to breathe and maintain their microclimate.
• Light weight wood blocks. This factor significantly simplifies construction.
• Easy processing with cutting tools. The block can be easily given any desired shape.

• Easy to use. When laying wood concrete blocks, they do not require professional skills.
• Resistant to mold, mildew and pests. The material has class IV biostability.
• High thermal conductivity. For this reason, wood concrete is often used in the construction of private houses.
• Shrinkage resistance. In this case, walls and partitions will not crack.
• High sound absorption. Thanks to this, the material can also be used for the construction of industrial buildings.
• Resistance to seismic activity.

The disadvantages include the following factors.

• If measures are not taken to protect against moisture, wood concrete quickly begins to decompose, losing its properties.
• The blocks do not have a perfectly flat surface due to the characteristic features of the composition.
• Arbolite walls require additional finishing.
• The material has a low level of adhesion to plaster mixtures.
• Due to the huge number of handicrafts, low-quality goods are often found on the market.
• Poor range of products.
• The lack of large-scale production affects the high price of the material and difficulties with delivery.

Why is it not shameful to insulate with sawdust?

As you can see, even at the planning stage you are already overloaded with information about the insulation material itself, so why should you choose it? Maybe it’s better to go and buy a modern insulating material, which is easy and quick to work with, and it holds heat better? All this is true, but sawdust is an exclusively natural product; it does not contain any chemicals, which cannot be said about any modern industrially produced insulator. Yes, the newest materials do not rot, do not burn, do not deteriorate, but they release all the substances of which they are composed and with which they are impregnated.

What should people with allergies do? Such an unhealthy spirit will only worsen their condition. Or children, who, thanks to such an atmosphere in the house, can easily catch the disease? Then you have to make concessions and turn away from progress, and resort to the old and reliable method of insulation. This is not to say that sawdust does not hold heat well; with the right approach to installation, you will receive effective protection, and, moreover, for an insignificant price, and you will get the filler itself for free.

These are undeniable advantages, but be prepared for the fact that the simplicity of work and the lack of specific requirements for tools at the insulation stage will end if you need to use this area for household needs. For example, this ceiling will also be the floor for the next floor or a functional attic, where you plan to store a lot of things. The whole point is that it is absolutely impossible to place anything on sawdust, which is poured between the beams and covered with film, and if you mix it with clay or cement, although you will get a solid flooring, any object with a large weight will press holes in it .

So, formally, we can assume that in most cases, by insulating the ceiling, you also insulate the floor, that is, you will then have to lay it on top of a layer of sawdust, because today every square meter counts. It is appropriate to cover a layer of clean wood waste and a mixture with clay with boards, but the cement-bonded particle composition can even serve as a screed for other types of flooring, subject to careful leveling. So, we can summarize that sawdust-based insulation is hypoallergenic, affordable, natural and does not require special skills to work with, but is not suitable for all surfaces, is demanding on the quality of the filler and is unsafe in case of fire.

Block composition

For the production of wood concrete, wood waste, as a rule, is taken from coniferous species - they are less susceptible to biological destruction. Cement is used as a binder (sometimes, to reduce the cost, part of it is replaced with clay and lime). There are quite a lot of recipes, but as a rule, they take an amount of cement with water equal in weight to the weight of dry aggregate.

To increase the strength of chip concrete, sand is added to it, but one should take into account the fact that with an increase in the amount of sand, the weight of the wood concrete increases and its thermal insulation properties decrease.

Also, the composition of chip concrete (and other materials with wood waste) necessarily includes special salts that make wood waste non-flammable, and they are practically not affected by fungi and bacteria.

Tips from the professionals

1. To prevent the appearance of rot and the spread of rodents, 5-10% dry lime is added to the sawdust.
2. Fire safety requirements are the law. You cannot use insulation made from sawdust with cement, dry sawdust mixtures in places where walls are heated: stove pipes, electrical wiring.
3. Shrinkage of sawdust is a natural process; after two years you need to check the level and, if necessary, add insulation.
4. Fresh wood waste does not have good enough adhesion to water, which means you need to take sawdust no “younger” than 3-6 months or add liquid glass to the compositions.
5. As reviews show, the only material comparable to sawdust in terms of its technical and practical characteristics is mineral wool. The consumption is the same, but the environmental friendliness and price of sawdust are much more favorable.
6. The flammability of the waste product can be eliminated by treatment, and the attractiveness for rodents can be eliminated with copper sulfate, brown acid, and boric acid.
7. It is best to lay thermal insulation in the warm season, this allows the sawdust to dry well and the mixture to dry completely.
8. The use of pine sawdust is more acceptable due to the resin content that repels bugs.
9. To process the mixture during the construction and insulation of a bathhouse, you cannot use copper sulfate - it is a poison that, when heated, releases fumes that are very dangerous to health.

Using sawdust is beneficial both economically and environmentally. The insulation is suitable for all work objects: walls, roofs, floors - the video will guide you through all stages of work. And, in addition, the product is available for transportation, has an almost unlimited shelf life and can be mixed with various additives.

Nuances

Before filling wooden forms with sawdust-concrete mixture, they are placed on flat plastic or steel pallets, sprinkled with a thin layer of sawdust. Then, wooden plugs wrapped in roofing felt are installed inside the cells, which are necessary to create holes in the blocks.

When the mixture is placed in the mold, it is compacted with a special tamper. Over the next 3-5 days, the material acquires from 30 to 40 percent of brand strength. After this period, the casting mold is disassembled and the plugs are removed from the blocks. Finished but not yet dried products are left in the same place for 3-4 days. During this time, their strength increases to 60-70 percent.

Arbolit

Sawdust concrete is often confused with another building material - wood concrete, which is completely wrong. According to GOST, wood concrete is defined as concrete made with cement binder, chemical additives and organic solvents. However, in the classic version, wood concrete involves the use of wood chips. It is this that determines its unique properties.

Exactly like sawdust concrete, wood concrete is an environmentally friendly wall material, characterized by high levels of fire resistance and thermal insulation. Nevertheless, these two materials, despite the similarity in structure, have fundamental differences. The fact is that in the production of wood concrete, instead of small sawdust, which cannot have sufficient strength properties on their own, special wood chips are used, the size of which is strictly standardized. Sawdust, unlike wood chips, cannot sufficiently reinforce (strengthen) the wall block and give it “ductility”. Thus, wood concrete concrete is stronger than sawdust concrete in terms of bending strength and the ability to undergo temporary deformation without complete destruction. To be fair, it is worth noting that sawdust concrete is superior to other types of lightweight concrete in this indicator.

To strengthen the blocks, fill voids and reduce shrinkage, a lot of sand is added to the sawdust concrete composition, and a lot of lime or clay is also added to save binder material. The use of a large amount of sand negatively affects the fire resistance of the material we are considering - at a temperature of +573 ° C, sawdust concrete changes in volume, which can lead to cracking. In addition, due to the significant sand content, the structural characteristics of the blocks are reduced. So, for sawdust concrete to reach the strength of grade M25, its density should be 950 kg/m3. Due to the high density, the cost of the material and its delivery increases, and construction work becomes more complicated.

Wood concrete of a similar brand has a density of 500 to 700 kg/m3. Considering that with increasing specific gravity the heat-saving properties decrease, the thermal conductivity of sawdust concrete and wood concrete differs by more than two times in favor of the latter. This difference is due to the low amount of wood in sawdust concrete compared to wood concrete: approximately 50% versus 80-90% wood chips. This negatively affects such properties as providing passive ventilation of the room. Here, again, it is worth noting that in this parameter sawdust concrete is significantly superior to most wall materials. It is excellent for the construction of low-rise buildings and is second only to its “rival”.

Thus, calling sawdust concrete wood concrete is extremely incorrect, since these are completely different materials. The only similarity between them is the presence of a wood component in the composition.

Sequence of work

We have already become familiar with the composition of the mixture used to make a floor screed with sawdust, but there is no point in saying much about the technology, since it is similar to laying a cement-sand (concrete) screed. After mixing the ingredients, gradually add water until the consistency of thick sour cream is obtained. It is very important to use river or quarry sand of medium fraction.

It is important! It is worth choosing high-quality sand that does not have clay inclusions, which may not have the best effect on the quality of the future structure.

In the next video you will see how the installation process takes place, and as you can see, doing this is no more difficult than laying a classic concrete screed. The difference is in the thickness of the layer, and in the fact that it is cement and sawdust, and not crushed stone or other filler. The first layer is 7 centimeters thick, and this is enough to forget about warm socks and slippers - what we started with. It all starts with installing the guides, and this is not difficult; we tighten the mixture in the standard way. After pouring the first layer, remove the lath and lay the second layer in the same way (you shouldn’t wait until it dries).

Production technology

Today, several methods are used for making wall blocks for external and internal walls. Most often they are produced by direct pressing or using vibration casting (vibrocompression).

The first method is a relatively young and fairly low-cost technology. It provides for daily curing of wood concrete in molds. But the resulting mass is not uniform, which threatens internal stress in the finished product.

However, the basic manufacturing process is the same in both methods.

It consists of three important stages.

1. Sorting and crushing of organic matter.
2. Mixing wood chips with chemical components, cement and water. The operation takes 10 minutes.
3. Forming and drying the finished solution.

Types of sawdust products

You can insulate the floor not just with sawdust, but with insulating materials created using them.

Sawdust granules

They are obtained by mixing sawdust with glue. Antiseptic additives must be included in the mixture. The granules retain the thermal insulation properties of ordinary sawdust, but have better resistance to rotting and are difficult to ignite.

Sawdust granules

Sawdust concrete

These are ready-made blocks of insulation obtained by mixing sawdust with sand and cement in different proportions. It is used for construction purposes, but for floor insulation it is better to take blocks with a high sawdust content. They are less durable, but their thermal conductivity is lower.

Sawdust concrete blocks

Arbolit

To make arbolite blocks, large wood chips are used, mixed with cement mortar without adding sand.

Arbolit

Types of blocks with wood fillers

Chip concrete or wood concrete can also be divided into the following types:

• thermal insulation. Density up to 450 kg/m3;
• thermal insulation and structural. Density 450-650 kg/m3;
• structural. Density 600-800 kg/m3.

Wood concrete and sawdust concrete are used in the form of wall panels, as a monolithic fill and in the form of blocks of various sizes. The peculiarities of monolithic pouring are that the wall made of wood concrete sets relatively unevenly and warping is possible. And they try not to make blocks more than 20 centimeters in thickness, since they will take a long time to dry, and laying heavy blocks is more labor-intensive.

Another distinctive feature of chip concrete is that walls built from it do not sweat or flow. Since, on the one hand, it retains many of the beneficial properties of wood, and on the other hand, compared to other building materials (brick, foam concrete), it has higher vapor permeability.

You can even talk about partial displacement ventilation through walls made of wood concrete and sawdust concrete. This is a unique type of ventilation, when air leaks through the structure of the material itself, it heats up, passing through numerous fibers and displaces the already heated “exhaust” air in the house.

Thanks to this, there are no “stagnant zones” in houses made of chip concrete, and the costs of installing ventilation are significantly reduced (or completely eliminated as unnecessary). And as a result, heat loss at home is also reduced.

We can summarize:

1. Wood concrete (and all blocks with wood fillers) is a material for those who care about their family and at the same time want to reduce the costs of building a house. After all, wood concrete is 4 times lighter than brick, which means you need a less strong foundation (cheaper).
2. A 35 cm thick chip concrete wall corresponds to 1 meter brickwork in terms of thermal insulation properties.
3. The costs of the ventilation system are reduced.
4. Chip concrete or wood concrete is not susceptible to damage from rodents, insects, fungi, bacteria and fire, compared to a conventional wooden house.
5. Due to the porous surface, plaster and putty are perfectly adhered to wood concrete.
6. Arbolite is easy to process; it can be easily chopped, sawed, driven in nails and screwed in screws.

On heaving and other unstable soils, chip concrete (arbolite, sawdust concrete) is practically irreplaceable. After all, it has good elastic deformation. And at the slightest movement of the foundation (due to frost or soil movement), other masonry materials will crack.

And chip concrete may wrinkle a little, because the shavings and wood chips included in its composition act as reinforcing fibers on one side and can be dented on the other side.

Among the relative disadvantages and features, it should be noted that walls made of chip concrete are recommended to be plastered or covered with bricks on the outside, or otherwise protected from direct exposure to precipitation. Also, when making a house from chip concrete, you need to ensure that the material is of high quality, because some craftsmen can sell frankly low-quality material, discrediting such an excellent material.

Sawdust concrete? I will make floors from it!

And when I learned about sawdust concrete, having studied this material, I immediately and irrevocably decided - “this is the right topic, I’ll do it!” In terms of price, I won’t say that it is more profitable than heavy concrete, you can calculate it yourself, based on the fact that a bag of shavings and sawdust for 140 liters costs 100 rubles . (this is the lowest price I found here). But the finished mixture of sawdust concrete is much lighter (4 times) than ordinary concrete, first of all. Secondly, this material is quite warm, and you can avoid insulation and save money. In principle, I will say that if you do not make a warm water floor, you can refuse insulation when pouring ordinary floors on the ground - once the earth has warmed up under the house, it will maintain the temperature, the earth is generally a good heat accumulator. So for me, the decisive factor was that I could fill these floors myself without much effort, as I was convinced from experience. And the strength of such floors with a thickness of 8 cm is quite sufficient, taking into account the fact that I will have light partitions made of gypsum fiber board. Although I will note that in the places where they pass, I make the mixture a little more saturated with cement, from my standard proportions, which I will mention below.

Best answers

I'll be back:

I don’t know the consistency, but you know that sawdust must be dehydrated and specially processed. composition? and read about brisolite, the same thing...

Online magazine Tips for owners:

Sawdust concrete, also known as wood concrete, is a mixture of sawdust, sand, water and cement. Correct consistency? It is not entirely clear what is meant, if proportions, then it depends on the desired brand. In its simplest form - three buckets of sawdust, a bucket of sand and a bucket of cement. If stronger, two buckets of sawdust, half a bucket of sand and a bucket of cement. In addition, if the sawdust is fresh (up to 2 years), be sure to add about 5% of the volume of calcium chloride, lime or liquid glass.

If the consistency is in terms of the amount of water, then again it depends on the desired brand, but in general it is about 0.8 of cement. The fact is that for wood concrete, no matter how much water you add, the sawdust will be absorbed, but you won’t get a liquid composition. Therefore, you don’t need to pour a lot of water. Only the strength will decrease. From experience, the composition is something like wet sawdust, we pour it into the formwork and tamp it well. The layer is no more than 20-25 cm. It is best to make a mold from boards or sheet metal and prepare blocks, and then build from them. But you can also install formwork from boards in layers. At the bottom of such formwork we make a support beam. They stuffed it, waited two or three days, and rearranged it. The timber (20x20 maximum), if done carefully, gives a kind of seam, the wall turns out to be rusticated, quite interesting. As for freezing, that's the question. 40 cm of wood concrete is the same as a log of 25 -30 cm in thermal conductivity. You won't freeze, but you'll have to light the stove.

But in general, wood concrete is afraid of water, so it’s better to veneer the outside than anything else, but you can immediately lay an additional layer of insulation. Well, the number of floors is no more than two floors...

Preparation of raw materials

For screeding, ordinary sawdust is taken, which can be found in large quantities at sawmills. Before use, they are pre-treated with antiseptic agents and dried. Then they are sprinkled with slaked lime. This must be done to protect against rodents that live in our homes. The fact is that untreated wood particles are an excellent place for them to live and reproduce.

Hydrated lime needs at least a tenth by weight. After backfilling, the materials are mixed well with a shovel to create a homogeneous mass.

Mixing

One of the most labor-intensive stages in the production of sawdust concrete (even a novice builder can make blocks with his own hands) is mixing, so it is recommended to use a concrete mixer or at least a mortar mixer. This will make the mixing procedure not only more comfortable, but also of higher quality. Before pouring dried sawdust into a concrete mixer, they must be sifted through a sieve with a mesh side of 1 cm. Then you can mix the sawdust with cement. Only after this clay or lime dough, prepared in advance, is added to the mixture. All components must be thoroughly mixed and diluted with water. Water should be added in small portions. After each topping, it is necessary to mix the sawdust concrete mixture. The proportions of the components are set individually, depending on the purpose of the final product. The more load the blocks bear, the higher their grade.

If sawdust concrete is mixed properly, then when compressed in a fist, the mixture will form a plastic lump, on which, in the absence of drops of water, indentations from the fingers will be visible. This is considered the main indicator of a properly prepared mixture.

The process of pouring sawdust screed

The screed is performed in the same way as a regular cement screed.

But we maintain the correct concentration of sawdust in each layer:

• bottom layer - 6 buckets of sawdust per bucket of cement;
• the top layer should be made with less sawdust (3 buckets of sawdust per bucket of cement).

We level two guide rails, the distance between which is approximately 700 mm. We immediately fill the slats to secure them, then we fill the entire bottom layer, approximately 7 cm high (for a bucket of M400 cement, 2 buckets of sand plus 6 buckets of sawdust).

We make the second layer 3 cm high with less sawdust (3 buckets). We level the solution evenly along the height of the slats. After filling the first strip, you can remove one distant strip and move it further to the next section. We immediately fill the hole resulting from the lath with a solution of sawdust concrete and level it before the screed has time to harden.

Again, level the slats and fill the next section in the same order. Experienced specialists manage to use only one rail.

It is important to know that it is not advisable to pour the screed onto the ground. According to generally accepted standards, you should always make double ties, always using waterproofing to reduce possible dampness.

The first screed should be about 3 cm with the following composition: 1 bucket of cement, 3 buckets of sand and 2 buckets of fine crushed stone (if the soil is not disturbed).

If the soil is disturbed, immediately add a 3-4 cm layer of sand, compact it and fill it with water. Reinforcement 6 mm in diameter is placed on top, cells measuring 250x250 mm and filled with screed. Waterproofing is done on top of the screed using a primer, or sheets of regular roofing felt are placed with an overlap of 15 cm.

The screed in the second layer is made of wood concrete. If desired, it can be made thicker (up to 15 cm) for more warmth.

The most valuable thing about this screed method is the fact that it will cost as much as 60% less than a conventional cement-sand screed, plus many other advantages.

Ultimately, we get a strong and reliable screed. If you use it on the first floor, the floor will be much warmer than concrete. Application on the second floor will provide excellent sound absorption and a warm floor, much warmer than cement. With such a screed you can reliably insulate the attic if you pour it over slabs 15-20 cm high, putting 8 buckets of sawdust in the first layer. Such insulation will significantly save you money. The height of the screed layer may vary depending on the climate; these parameters are suitable for the region of Ukraine.

An interesting case was told by one builder who uses wood concrete as a screed. By mistake, he filled the heated floor with a (water) screed with sawdust instead of the usual one, 7 cm thick from the bottom of the pipe. When the heated floor was turned on, it turned out that the floor temperature did not change. We increased the temperature in the boiler to maximum - the result was the same! Arbolite has poor thermal conductivity and perfectly maintains a stable temperature. I had to disassemble the screed until the customer found out. And here again a surprise - the tie turned out to be quite strong, I had to use a hammer drill to remove it. As a result, too much time had to be spent on this work.

Compound

As the name suggests, the defining element of this material is sawdust. In addition, sawdust concrete contains sand, cement, as well as clay or lime. Due to its favorable sanitary and hygienic characteristics, the material is optimal for the construction of residential walls.

The density of the building material depends on the ratio of sawdust and sand. The more sand and binders in sawdust concrete, the greater its density. In this case, the material has high strength, but low thermal characteristics. As the amount of sawdust increases, the strength decreases. Along with it, the frost resistance of the material and its water resistance are reduced, which, in turn, negatively affects the corrosion resistance of steel reinforcement. Reinforcement is used when laying walls. From the above we can conclude that before you start building a house from sawdust concrete, it is necessary to study the features of the influence of the composition of the material on its properties

When choosing one or another composition, it is worth taking into account the thickness of the walls, the number of storeys of the building and the purpose of the walls (internal, external or load-bearing)

Why and how is heat lost?

Any building materials, to one degree or another, have the ability to transfer thermal energy through themselves, therefore parts of the house built from them also transfer heat.

Moreover, the movement of energy is always directed in the coldest direction, that is, in the summer from the street to the house, and in the winter from the house to the street.

The intensity of these heat exchange processes depends on:

• temperature differences;
• location of the heat transfer area;
• its thermal conductivity;
• thickness and shape;
• the presence of various defects that reduce thermal resistance.

Any house can be divided into:

• window;
• doors;
• walls;
• floor;
• ceiling;
• roof.

However, heat transfer even within the same part can vary greatly. For example, one of the cladding boards of a frame house has rotted, so in its place the thermal conductivity will be slightly higher. Or the inter-crown insulation in a timber house has collapsed.

There can be many reasons. However, in healthy houses the reason is always the same - excess thermal conductivity caused by insufficient thickness of the floor, walls or ceiling.

Increasing the thickness of walls with standard building materials will be very expensive, so the use of substitutes is more popular. With this approach, not only the thermal insulation properties of the new insulation are important, but also qualities such as:

• ease of installation;
• the ability to insulate not only walls, but also floors and ceilings;
• purchase and delivery costs.

In terms of these parameters, sawdust outperforms many insulation materials for a number of reasons:

• installation of such material does not cause any particular difficulties;
• they are suitable for insulating any parts of the house;
• are much cheaper than any other materials.

After insulating a house with sawdust, living in it becomes more comfortable, because the temperature in the rooms is less dependent on the temperature outside.

In addition, heating and air conditioning costs are reduced, because less powerful climate control systems can be installed and turned on less frequently to maintain the desired temperature.

Pros and cons of sawdust concrete

Sawdust concrete is increasingly being chosen to create country houses. Its use can bring certain advantages, since the following positive qualities can be identified in the material:

• the load on the foundation is noticeably reduced;
• increased thermal insulation is observed;
• construction costs are lower;
• the walls are frost-resistant and non-flammable;
• there is protection from the effects of microorganisms;
• the house has excellent sound insulation;
• You can line the walls with different materials.

However, like other building materials, sawdust concrete has some disadvantages that also need to be taken into account during construction:

• load-bearing capacity is low;
• blocks are able to absorb moisture;
• it is necessary to cover the walls;
• the material shrinks.

Proportions and composition of sawdust concrete - 2 ways to prepare the solution

The excellent characteristics and composition of sawdust concrete make it possible to use it in the construction of monoliths and small wall blocks of low-rise buildings. Sawdust is a product of organic waste, so the heat transfer of the new building material is greater than that of conventional concrete. Since there is no such material on the construction market, builders make it themselves. However, the requirements of GOST 6133–99 apply to sawdust concrete blocks, as well as to other concrete stones. Therefore, you need to know the manufacturing technology and adhere to the specified proportions.

Comparison with other materials

For the construction of a residential building or outbuilding, it is very important to choose the right building components. But you should know that there are no good or bad materials, there are only suitable and not so suitable ones.

Expanded clay concrete. Just like wood concrete, it is an environmentally friendly material and belongs to the class of lightweight concrete. It consists of expanded clay (burnt clay or shale), cement, sand and water. However, expanded clay blocks have a thermal conductivity index (0.5 - 0.7 W/m K), that is, slightly worse than that of wood concrete. Therefore, from the point of view of heat preservation, it is better to choose wood blocks for the house. Despite its higher strength, expanded clay concrete may not withstand excess pressure. This is due to the hollow space inside the product.

• Sawdust concrete. The composition of this material is very similar to wood concrete. In both cases, wood waste is used. Just like wood concrete, it is considered an environmentally friendly building material, has high heat-shielding qualities and is resistant to stretching, bending and impact.
• Aerated concrete. The cellular composition consists of sand, cement, water and a gas-forming agent, due to which characteristic porosity appears. Unlike wood concrete, aerated concrete has a clear geometry of the product. The material is characterized by high water resistance and fragility. If we compare this material and wood concrete, then in many respects aerated concrete wins.

• Polystyrene concrete. This is a type of lightweight concrete consisting of Portland cement, polystyrene foam granules and air-entraining additives. It is distinguished by its high structural strength. It shrinks, but significantly less than gas blocks and foam blocks. Just like wood concrete, it has good thermal insulation properties. Polystyrene concrete blocks do not require additional insulation.
• Straw blocks. They are a building material consisting of environmentally friendly raw materials - pressed straw. Straw blocks have a better thermal conductivity index than wood concrete (0.05 - 0.065). But they also have disadvantages such as high moisture absorption and low fire resistance.

• Beam. This is a highly environmentally friendly breathable material made from laminated boards or logs. It has excellent thermal conductivity and high strength. It is a worthy competitor to wood concrete.
• Gas silicate. This cellular material is obtained from a solution of fine sand, lime, gas-forming additives and water. The structure is similar to aerated concrete, but there is a difference in composition, and therefore in properties. It is characterized by good thermal conductivity, high fragility and increased moisture absorption.

• Fibrolite. This is an analogue of wood concrete with a very similar composition. In both cases, wood waste acts as components. But if in the first option there are shavings, then wood fiber is used in fiberboard, made in the form of thin and narrow strips. Just like wood concrete, it has good thermal conductivity (0.08 - 0.1 W/m K) and needs additional protection from moisture.
• Sibit. Consists of concrete, gypsum, aluminum powder with the addition of surfactants and water. It is considered an environmentally friendly material, since the reactions result in the formation of artificial stone. It has extremely high frost resistance (up to 250 freezing and thawing cycles), but low fracture strength. It is usually not used for low-rise buildings.
• Adobe. This is the oldest building material, consisting of environmentally friendly raw materials - clay soil and straw. Adobe has an excellent thermal conductivity coefficient (0.1 – 0.4). However, it has an important drawback - increased moisture permeability.

About the pros and cons of wood concrete in the video below.

Features of laying on the ground

When building a new house, you often have to lay the screed directly on the ground, but in the case of a sawdust concrete screed, certain preparation is required. Experts, and we agree with them, advise pouring a layer of sand 3-4 cm thick, and for the strength of the structure, reinforcement d = 6 mm or other reinforcing material should be laid on top of the sand. To impart good waterproofing properties, we lay roofing felt or other waterproofing material on top of the first layer. The next layer gives the structure strength, and it is better that the sawdust content is halved, and the layer itself is twice as thick. To finish our “oil painting”, you can use plaster with the addition of sawdust to cover the walls, and lay out the walls from the same environmentally friendly sawdust concrete blocks.

Final drying

The last stage of sawdust concrete production is drying. For final drying, the blocks must be moved under a canopy or covered with polyethylene. It is advisable that they be in a draft. When laying blocks, it is necessary to leave gaps between them for ventilation. As a rule, laying is done in the form of pillars. To begin with, a couple of wall blocks are placed on two baked bricks, then a couple more are placed across them, and so on. After a month, the blocks will harden, dry and reach 90% strength. To ensure they are as durable as possible, it is recommended to wait another three months before starting construction. It’s up to you to ignore this rule or not; it all depends on the type of building for which the material is being prepared. For example, to build a bathhouse from sawdust concrete it is not at all necessary to wait until the products are 100% dry. Completely finished blocks must be hard, durable and free of cracks. If dropped from a meter height, they should not break.

Main characteristics of sawdust

There are several characteristics that help you compare different insulation materials and choose the one that best suits your specific situation.

These are the characteristics:

• cost (excluding delivery);
• thermal conductivity;
• vapor permeability;
• resistance to high humidity and condensation;
• life time.

Cost is one of the most important parameters, especially if you have to insulate a large area. After all, the cost of 1m2 of the cheapest modern material, even without taking into account delivery costs, exceeds 150 rubles.

Therefore, when insulating a large house, the cost of purchasing insulation alone amounts to hundreds of thousands of rubles. Sawdust is much cheaper.

You can read more about their costs here.

Thermal conductivity is another important parameter on which the thickness of the layer required to reduce heat loss to a given level depends.

In this parameter, sawdust is inferior to all modern insulation materials, but you can slightly increase the thickness of the layer and bring heat loss to a given level.

In terms of thermal conductivity, 10 cm of wood sawing waste corresponds to a layer of mineral wool 8–9 cm thick and a layer of polystyrene foam 7 cm thick.

Vapor permeability is the ability of a material to pass water vapor through itself. This characteristic is very important for materials that are used to reduce heat loss in breathable houses built from wood or hollow clay bricks.

In terms of this parameter, sawdust leaves any other materials far behind, because of all modern insulation materials, only mineral wool allows steam to pass through at least a little. The rest of the materials completely block this process, which is why the microclimate in the house changes not for the better.

Resistance to high humidity and condensation is important for any insulating material, because humidity is always present in the air, and condensation occurs when temperatures change.

Sawdust absorbs excess moisture, and after a while, when air humidity drops, it releases steam. Therefore, humidity cannot harm them, which cannot be said about mineral wool, which, even if it gets a little wet, sharply loses its thermal insulation properties.

The actual service life of a material can only be determined by its condition after some time.

Polystyrene foam, polystyrene and polyurethane foam rarely withstand 30 years, because they are destroyed by oxygen and ultraviolet radiation, mineral wool can withstand 50–70 years, and sawdust can easily withstand a service life of 150 years.

In Russia and other countries there are houses built in the early and mid-19th century and insulated with sawdust. Despite such a considerable age, the sawdust insulation is in excellent condition and does not require either repair or replacement.

All this allows us to draw an unambiguous conclusion - in terms of the totality of its characteristics, sawdust is in no way inferior to any modern insulating material, and when used correctly, it is noticeably superior to them.