Sawdust concrete house. Sawdust concrete house: an overview of the material, technology and a brief scheme of work Building a house from sawdust

The main advantage of the house, the walls of which are built of sawdust concrete, which is sometimes called wood concrete, is its relatively low cost, as well as ease of construction, since this construction material with confidence can be called an excellent alternative to most modern expensive materials.
Sawdust concrete as a building material has been known since the last century. It was specially created for the purpose beneficial use waste generated during the processing of wood at woodworking enterprises. At present, dozens of practical applications have been found for sawdust, and houses based on sawdust concrete have not gained a well-deserved wide popularity. However, this does not mean that this technology is forgotten. modern man. Nowadays, walls are being built from sawdust concrete country houses small private cottages.
Sawdust concrete can be used for construction bearing walls and partitions, and as an insulating material. In this article, we will consider the structural features of residential buildings based on this material, as well as talk about their main advantages and disadvantages.

Two technologies for erecting walls of houses using sawdust concrete

Sawdust concrete can be called a universal material on the grounds that its initial consistency is a liquid, fairly fluid mass. Thanks to this, builders can create from this material small blocks for the subsequent erection of walls or, having installed the formwork, to cast the walls completely, thus saving a significant amount of time and Money. Let's take a closer look at the advantages and disadvantages of both technologies.
The manufacture of individual blocks from sawdust concrete is a rather time-consuming event. Compared to the production of blocks based on other raw materials, sawdust concrete bricks will take a very long time to gain the required strength. As a rule, four months pass from production to the moment when blocks of sawdust concrete can be laid without fear of shrinkage. If the developer does not have the opportunity to wait all this time, it is better to use the technology of monolithic wall construction using this material.

However, if you look at the situation from the other side, it is unlikely that anyone will object that building the walls of a building using separate blocks small size much easier than creating a massive, highly reliable formwork and pouring the prepared mortar into it.
Moreover, during construction, massive formwork will have to be moved from one place to another more than once, while performing the next pouring, it will be more and more difficult to place the source material in the formwork cavity. That is why building a house from individual sawdust blocks is more common in comparison with monolithic casting from the same material.
The remaining subtleties of building houses using these two technologies differ little from each other. Thus, if the developer has the opportunity to buy ready-made blocks of sawdust concrete, it is better to use block construction technology.

Solution preparation technology

Similar to traditional concrete, its sawdust counterpart can have different densities, as a result of which sawdust concrete of various grades is present on the market. According to building codes, there are the following density values ​​for sawdust concrete: 500, 650, 800, 950 kg/m³. What characteristics are affected by the density of a given material?
Of course, the ability of load-bearing walls to withstand the loads acting on them directly depends on the density of sawdust concrete. In the case of using material for individual construction, such loads will be the weight of the roof or the second floor of the building. When erecting the walls of a house, it is best to use sawdust concrete, which has maximum strength, even if building a second floor and equipping a building with a metal frame roof is not in your plans.

Below are the proportions of raw materials used for the manufacture of all grades of sawdust concrete.

• During the manufacture of the M5 brand, which has a density of 500 kg / m³, medium fraction sawdust, 50 kg of sand, 50 kg of cement, 200 kg of lime or clay are used.
• During the manufacture of the M10 brand, which has a density of 650 kg / m³, 200 kg of sawdust, 100 kg of sand, 100 kg of cement, 150 kg of lime or clay are used.
• In the manufacture of the M15 grade with a density of 800 kg / m³, 200 kg of medium fraction sawdust, 350 kg of sand, 150 kg of cement, 100 kg of lime or clay are used.
• To create the M20 grade, which has a density of 950 kg / m³, use 200 kg of medium fraction sawdust, 500 kg of sand, 200 kg of cement, 50 kg of lime or clay.

Now a few words should be said about the intricacies of the process of preparing sawdust concrete. During the manufacture of sawdust concrete, all its constituent components are never mixed at once, as the result will be a solution of low quality. The implementation of the technology for the production of sawdust concrete mortar involves the preparation of two various formulations, one of which contains sand, cement and dry sawdust, the second contains clay and lime dissolved in water.
After the two fractions are prepared separately, they are placed in one container and thoroughly mixed. At the same time, each individual chip of wood should be well coated with a solution. A well-prepared solution of sawdust concrete should not disintegrate when its sample is compressed by hand, it should not be excessively liquid. The consistency of a well-prepared sawdust concrete should be similar to a semi-dry plastic mass.
The subtleties of building a house using monolithic sawdust concrete
As mentioned earlier, the construction of the walls of the house using sawdust concrete contains a sufficient number of features, the exact observance of which is necessary, since this affects many of the operational characteristics of the future house, which include the duration of the building's life. Let's consider these subtleties in more detail.

First of all, it should be said that sawdust concrete is not suitable for building a foundation. The foundation must be built using traditional materials such as ordinary concrete or brick. The constructed foundation must be at least half a meter above the ground level. The foundation of the future house with sawdust concrete walls must be securely insulated from all sides - from above and from the sides. Such reinforced waterproofing will not allow moisture to penetrate through the concrete into the walls of the house based on sawdust concrete.
Reinforcement of the building in the corners should be mandatory. The best option for two-story house we can consider the pouring of concrete supports in the corners of the house, in the thickness of which reinforcement will be laid. For one-story monolithic buildings, it is enough to perform reinforcement in the form metal frame laid in a horizontal plane at all corners of the structure from bottom to top.
Continuing the theme of building reinforcement, it should be said that in a sawdust concrete house it is necessary to reinforce door and window openings. Reinforcement is carried out according to the standard scheme - the reinforcing belt is laid along the perimeter of the corresponding openings.
Also, it is very important to create a reinforcing belt from ordinary concrete, which will be poured along the perimeter of the building on top of the load-bearing walls. The thickness of this belt must be at least 100 mm. During the creation of this reinforcing belt, reinforcement with a diameter of at least 10 mm is used. It must be borne in mind that this reinforcing belt will take on the load of the roof of the building.
It is very important to fulfill the condition of competent removal of melt or rain water from the roof, since liquid falling on the walls will adversely affect performance characteristics at home. To this end, it is necessary to design a roof overhang with a minimum value of 600 mm.
We can say that this is a list of all the main subtleties that must be taken into account during the construction of a private house and using sawdust concrete. There are several less important requirements. Among them, the most important are the organization of a sufficient width of the blind area around the perimeter of the building, as well as a thoughtfully designed roof drainage system.
I would like to add a few words about the thickness of the walls of the house being built. Considering that sawdust concrete is capable of excellent heat retention, it is sufficient that the minimum wall thickness is 400 mm. This indicator directly depends on the climatic zone in which the subsequent operation of the building will be carried out. In fairness, it can be noted that even a building with a wall thickness of 500 mm has sufficient middle lane energy saving features.

Considering the advantages and disadvantages of a house whose walls are built of sawdust concrete, it should be noted that there are a lot of both. At the same time, almost all the advantages cover the existing disadvantages and vice versa. As a result, it is impossible to give a specific answer to the question of the possibility of using this material in individual construction. Each owner of a suburban plot of land who wants to build on it own house, must decide for himself the issue of using sawdust concrete or other building material, based on his financial capabilities, as well as taking into account local construction conditions.

The undeniable advantages of sawdust concrete include the following characteristics:

• Own low cost of material. All materials included in sawdust concrete are not scarce or expensive, so you won’t have to pay large sums for the purchase of ready-made blocks. Furthermore, independent production blocks or the creation of a monolithic structure will make construction even cheaper.
• Simplicity of all stages of construction. The course of self-erecting the walls of a house from sawdust concrete is absolutely no different from the technologies for building buildings using other block materials.
• High construction speed. As already known, a sawdust concrete house can be built not only using blocks, but also by casting walls, which greatly speeds up the process of building a building.
• Excellent thermal insulation properties. A house with sawdust concrete walls has ideal interiors. climatic conditions. The inside of the building is warm in winter and cool in summer. Due to the high thermal insulation ability of the material, the home owner can save money
• High sound insulation. Buildings made of sawdust concrete, due to the peculiarities of the internal structure of this material, practically do not let street sounds into the premises. As a result, the atmosphere of the house is filled with peace and quiet.

In addition to those listed above, there are many similar less significant advantages, which can be listed for a very long time. It is better to turn the reader's eye to the disadvantages that are inherent in all buildings built on the basis of sawdust concrete.

So, the disadvantages include:

• High hygroscopicity of the material. It should be noted here that during the rain, the walls of the house are not just quickly, but can be said to be instantly saturated with moisture. Of course, such a negative phenomenon can be combated, however, all existing methods of such a struggle entail an increase in the cost of construction.
• Low strength of the material. Compared to cinder block or aerated concrete, sawdust concrete has a lower strength. The structure, the walls of which were built using sawdust concrete, are not able to withstand significant loads, therefore, even when creating a second floor in them, it is necessary to work out the project very seriously.
• Short service life. If we compare buildings made of sawdust concrete with their counterparts created on the basis of OSB, then we can say that here sawdust concrete will be at its best. However, the time that concrete or brick houses, a building made of sawdust concrete will not be able to stand without damage or even destruction.
• Construction features. There are quite a few subtleties in the construction of sawdust concrete buildings, non-compliance with at least one of which will lead to many troubles during further operation.
• The need to create additional waterproofing of the outer walls, for the creation of which they will need to be plastered with a layer of the appropriate material of at least 20 mm.

Thus, knowing about all the advantages and disadvantages of a house made of sawdust concrete, each owner must decide for himself whether to use this material for the construction of his dwelling or to make a choice in favor of another. Although in this situation there are several options, in particular, sawdust concrete can be an indispensable material in the construction of various kinds of temporary buildings. Cheap and cheerful!

Concrete when using sawdust as a filler on line of concretes closer to the classics than wood concrete.

It's all about the presence of sand in the sawdust concrete.

No matter how similar in composition to each other arbolite and sawdust concrete - there is a difference, and it is, at times, significant.

We will not analyze the differences, we will consider in detail only the sawdust concrete itself.

There are types of sawdust concrete:

• heat-insulating(average density from 400 to 800 kg/m3);
• structural(average density from 800 to 1200kg/m3).

Like any other concrete, sawdust concrete gains strength best in heat and humidity, since moisture does not evaporate quickly and goes to the formation of cement stone.

pros

The main advantages of sawdust concrete are:

1. Cheapness of the main components.
2. Ease of manufacture.
3. The durability of buildings.
4. Environmental friendliness.
5. Excellent thermal protection.
6. A method of manufacture and application developed over decades of use.

Minuses

There is only one main drawback: not all sawdust will fit for this material. If, in the case of sugar, they were removed from the chips during resting, and according to the ratio of the volume of chips and the specific area of ​​the chips, the decomposition of sugars did not greatly affect the cement, then in the case of sawdust concrete, the process of sugar decomposition strongly affects the cement itself inside the block.

Manufacturing

In the process of producing sawdust concrete, it is important to take only the most suitable sawdust from those types of wood that have minimum sugar content. Optimal contenders for the second life of waste in sawdust concrete:

• pine;
• Birch;
• poplar.

Larch, despite the high characteristics of density and strength is in the last place with the highest sugar content.

If in spruce the beginning of strength development begins two weeks after setting, then the end occurs somewhere on the fortieth day after manufacture. But for larch, this period is much longer: from thirty days at the beginning of curing to one hundred and forty at the end.

All works on monolithic sawdust concrete should be done in the spring to be finished by autumn. Due to the released sugars, it is better to bring the sawdust to the condition in the fresh air, including watering the sawdust with water in order to wash away the remnants of sugar breakdown.

A couple of washes with water will already provide the sawdust with an acceptable condition for use in the sawdust concrete manufacturing process. Sawdust structure when stored in bulk, it will prevent the processes of decay and combustion from starting. Since they are not compressed, there is no need to be afraid of moisture.

Compound

Any brand of sawdust concrete contains:

• cement;
• sand;
• slaked lime;
• sawdust.

Differences in proportions observed only in the ratio of the components of the mixture.

Each brand of sawdust concrete has its own proportions.

Components

We prepare sawdust concrete with our own hands. Proportions of components per 1m3 ready mix display in the form of a table:

As you can see, with an increase in the amount of cement, the purpose of the blocks is more reduced to the construction of non-residential buildings. This is due to the change in the coefficient thermal conductivity of blocks, nullifying all efforts to heat the building. When using blocks of the M10 brand, the coefficient is 0.21, which is a very good indicator.

For the M15 grade, this coefficient is 0.24, which is caused only by a slight increase in the requirements for strength, respectively, and an increase in the amount of cement to obtain a durable block for the construction of a two-story house. For the M25 block, the coefficient is already almost 0.39, which is two times higher than that of the M10 block. This means that the M25 block is twice as cold, but from it you can build large rooms.

The golden mean for sawdust concrete is one-story buildings.

Proportions

The proportions of sawdust concrete are shown in the table:

In terms of volume, this means the following. In the manufacture of sawdust concrete:

1. Marks M10:
   • cement 0.5 buckets;
   • a little more than 1 bucket of sand (a bucket with a slide);
   • sawdust a little more than 3 buckets.
2. Marks M15:
   • cement a little more than 0.5 buckets;
   • sand 1.5 buckets;
   • sawdust almost 4 buckets.
3. Marks M25:
   • cement 0.5 buckets;
   • sand a little less than 1.5 buckets;
   • sawdust 3 buckets with two slides.

It is important to follow just such a recipe, because it was worked out for decades, much earlier than wood concrete. The lack of progression in quantity and proportions should not be embarrassing. In each case, the components work differently.

Hydrated lime as a component is used both as a means of sawdust desaccharification, and bypassing this stage, by introducing the required amount of fluff into the mixture.

Preparing the mixture

Surprisingly, the most easy way mixing is manual. When preparing sawdust concrete with your own hands, ordinary concrete mixers will not work. Due to the lightness of some components, they run the risk of remaining on the walls of the concrete mixer, or simply floating on top of the water. Any loading order.

You can first:

1. dilute cement in water;
2. add sand, sawdust and lime.

Another variant:

1. mix sawdust with lime;
2. add sand and cement;
3. dilute with water.

No matter what other people say, there is absolutely no difference in which option to choose.

As a result of the work, a homogeneous mixture is formed, in the structure of which there is sand with cement. These two components form cement stone. The lime neutralizes the sugars as they are released from the sawdust, and the sawdust itself is the filler. Lightweight concrete classic.

Machine kneading sawdust concrete functionally possible if there is a forced-type mixer, as in the production of polystyrene concrete. But even in that case, the order does not matter, since if the sawdust has already been treated with lime during preparation, then they are no longer afraid of water.

Sawdust concrete based on gypsum binder

It is worth mentioning a little about a mixture where building gypsum is used instead of cement.

And let people not be afraid of the setting speed of gypsum in combination with water, since these moments have already found a popular solution.

The problem is solved by adding ordinary water to the water. detergent, and it, as you know, gives water in a dosed manner to gypsum molecules that are in an unhydrated state.

Explanation: building gypsum in the form in which it is sold in stores has ability to connect with water, forming a formula already with it, and which is already a solid formation that is not particularly afraid of water.

Until now, the dispute has not been put to an end - is it possible to build external walls from gypsum-based blocks.

According to some reports, with proven technology (on hand) and when protecting blocks from atmospheric influence, it is quite possible to use these blocks for building exterior walls. You can definitely build internal ones.

The only question is the price for the binder, but in terms of the volume of sawdust and setting strength, we can say that the costs will be slightly higher, and the rate of curing is four to five times higher.

About sawdust size

The size of the sawdust does not matter if there is enough binder.

As a rule, sawdust is taken from a sawmill, and the differences in sawdust from a band sawmill and a circular sawmill are so negligible that they are not taken into account at all.

Here, the chips from the cylindering and calibrating machines will no longer work.

A homogeneous mixture will not work if there are fractions in one volume that differ from each other in volume by several hundred times.

Of the features of the process - it is important to knead so that when a lump of the mixture was picked up and squeezed with his hands, water would not flow from it in a stream. Although everyone's strength is different, and you need to approach this issue logically. And after the lump has formed - so that it does not crumble in the hands.

Including for these nuances, lime is present in the solution. She provides mutual adhesion both between sand and cement, and between them and sawdust.

Manual mixing of sawdust concrete with a shovel:

The use of sawdust concrete

A truly folk building material, as it is the most affordable of materials on the complexity of production. Perhaps people are noticing for themselves a wave-like interest in such materials. If earlier sawdust concrete was good option for the whole country, then with the wave of Western marketing, people in pursuit of fashion moved away from a reasonable choice.

It is only now that many have begun to turn to environmental friendliness and practicality building materials, and not something that was designed for completely different climatic conditions. Successfully erected from sawdust concrete:

• houses up to three storeys;
• garages;
• sheds;
• outbuildings;
• technological buildings.

Like any moderately hygroscopic material, sawdust concrete needs outdoor decoration, as well as aerated concrete and foam concrete.

If we consider sawdust concrete in comparison with autoclaved aerated concrete, then the water absorption of the latter is generally 200% of the mass of the block. Therefore, do not be embarrassed by the presence of sawdust in the blocks. A popular insulation that was produced in Germany at the beginning of the last century - ecowool - is generally made from what is collected in landfills.

Therefore, it is still worth figuring out what is more environmentally friendly - sawdust concrete with natural ingredients, or ecowool with hyper-content of bromine salts.

The walls of a house made of sawdust concrete compare favorably with similar buildings made of bricks or, for example, foam blocks, in their low cost, while not inferior to them in heat saving. Industrial production of sawdust concrete does not exist. The only thing manufacturers can offer is wood concrete, which has a higher price and consists of wood chips and concrete. The thing is that sawdust is an almost free component that can be purchased at any woodworking company for which it is garbage.

Content

• Compound.
• Manufacturing.
• Application.
• Pros and cons.

Compound

The composition of sawdust concrete is very simple and consists of very affordable materials in any region: cement with lime or clay, sawdust, sand and, of course, water. Additives to cement contribute to the elasticity of the mixture, which ensures the strength of the formed blocks.

Sand, of course, creates strength and helps reduce shrinkage during the drying process of the blocks. Here you immediately need to pay attention to the fact that it is better not to use river sand, since it does not fit well with other components of the solution.

Depending on the proportions of the components, sawdust concrete will have different grades, which in turn will differ in their characteristics. But still, the main component on which the quality of the material depends is the amount of cement, as the most expensive in the finished mixture.

For example, grades of sawdust concrete M5 and M10 have high thermal insulation properties and are used for the construction of basements. But the M15 and M20 brands are distinguished by their strength, frost resistance and moisture resistance, so they are used for the construction of the outer walls of buildings.

Manufacturing

The process of manufacturing sawdust concrete for the walls of the house has its own specifics of the work:

• Cement, additives (clay or lime) are thoroughly mixed with dry sand.
• In what is mixed, you need to add the right amount of sifted sawdust.
• Then all mixing and with the help of a dispenser gradually add water.

The resulting mixture quickly solidifies (within an hour), so it must be used as soon as possible: either poured into the formwork, or distributed into pre-prepared forms to obtain sawdust blocks. In this case, a concrete mixer will be very useful.

A few words about how much water is needed for a quality solution. There is a clear rule here: when squeezing the solution with your hand, water should not leave it. If the water leaves, its amount must be reduced and, conversely, in the case when the lump breaks up, water must be added.

In order for sawdust concrete blocks to be of high quality, they must be properly dried.
In this regard, the following should be taken into account:

• It is necessary to fold the blocks for drying in a draft.
• There should be a gap between the raw blocks.
• Protect blocks during drying from rain.

And finally, there are some rules for obtaining high-quality sawdust concrete, which have been developed taking into account the experience of the process itself:

• Sawdust must be free of impurities, dirt and dust. Why should they be sieved?
• The best option would be to use cement brand M400.
• Use a concrete mixer to mix the components.
• In the forms, the mixture is compacted.
• To make it easy to remove the finished blocks from the molds, the walls of the latter must be upholstered with linoleum.
• After the blocks have been taken out of the molds, they (the blocks) must still be air-dried for 12 days.

The best sawdust is sawdust from coniferous trees.

Application

Compared to brick or sawdust concrete, it has less strength, so it is used for the construction of one-story buildings, garages, summer kitchens, sheds, etc.

It should be noted that the walls of the house made of sawdust concrete are warm and strong enough. But this is only in the case when the rules for its manufacture were observed.

Pros and cons

Pros:

• Environmentally friendly material.
• In terms of its heat-shielding properties, it surpasses brick three times.
• The light weight of the blocks, which makes it possible to build a less solid foundation, which means saving money.
• One hundred ek to various deformations.
• Does not lose properties high temperature(heat).
• Easily machinable.
• In sawdust concrete, fungus and mold do not start.

Minuses

The main disadvantage of using blocks for the wall of a house made of sawdust concrete is its high water absorption, which can be compared with expanded clay blocks. However, this disadvantage can be overcome by additional processing of the material.

Modern building materials have a wide range of choices. Building a house out of them is quite simple. But not everyone takes into account that an alternative to the standard stone or has long appeared. You can use sawdust in the construction of a structure and build a house from sawdust concrete.

The project of a three-story house made of sawdust concrete

“Sawdust house” is a figurative concept. From this raw material, a modern building material is made, which is called sawdust concrete. In addition, sawdust is used:

• for ;
• for insulation of the entire building;
• for insulation etc.

If earlier they were simply considered waste products of joinery production, now they have become effectively used in various areas of construction.

What is sawdust concrete

This is a material that can be factory-made. Although this is in rare cases. Most often it is made by hand. Especially if you have everything you need.

Sawdust concrete belongs to the category. According to their technical and quality characteristics it is not inferior to natural wood. It is safe to say that it is environmentally friendly and endowed with a number of advantages.

Raw materials for the production of sawdust concrete

In addition to sawdust, the composition of the material includes:

• lime;
• cement;
• sand;
• water.

Sometimes craftsmen improve this composition by adding clay to it. Because of this, the strength and thermal conductivity of houses built from sawdust concrete increases.

The density of the material depends on the amount of sand, cement and sawdust used. Sand plays a significant role. The more it is, the denser the sawdust concrete structure is obtained. If it is less, the house increases the thermal conductivity.

Important. Sand can affect strength. Together with lime and concrete, it has excellent quality indicators.

It is worth considering that a certain amount of raw materials can provide frost resistance and water resistance of sawdust concrete. At the same time, the reinforcing masonry is also protected, which, under the influence of moisture, corrodes and destroys its structure.

In the manufacture of sawdust concrete for construction, such specifications houses:

• the thickness of the walls of the future house;
• the number of load-bearing walls;
• the number of interior partitions;
• number of storeys of the cottage.

Read also

Projects of houses and cottages with a pool

And you can build from this material not only a house. Quite often, utility buildings, garages, fences, etc. are erected from it.

Grades of sawdust concrete

Today, depending on the density of the structure, there are several brands:

The first two types are used for the construction of small houses, their reconstruction, insulation of basements and other things. The density of the structure is not too high.

More suitable for these works are grades M15 and M20.

How to make sawdust concrete with your own hands

Initially, the so-called dough is kneaded from:

It is best to carry out the mixing process in a concrete mixer. Gradually add all the ingredients. The consistency of the mass should be homogeneous. This will have a favorable effect on the structure of houses, since the surface of the material will be even.

After that, a solution is poured into pre-made wooden forms of any size, upholstered with linoleum or a special polyethylene tape. It dries pretty quickly. Only in order for the material to get stronger, it will take more than 3 months. Ready blocks of sawdust concrete are laid out under a canopy on the street. Moisture will come out of it gradually, which avoids the appearance of internal deformations.

Note. A house made of sawdust concrete, which has acquired natural strength, will be of better quality.

Advantages of sawdust concrete and its disadvantages

We can say with confidence that the construction of houses from this material is not particularly difficult. The blocks are quite large. The material is environmentally friendly.

The house will not need to be additionally insulated, since sawdust concrete itself is considered a heater.
Note. The material is able to qualitatively retain the same amount of heat with a wall thickness of 30 cm, as brickwork 1 meter wide.

It is worth noting that the sawdust concrete house will not have a large mass. Because of this, the load on the foundation is negligible. Accordingly, the cost of its construction will decrease.

It has a long service life. Wood and concrete can serve for 50-100 years. Especially if they are in conjunction with other components.

It is almost impossible to break it, only with the use of special equipment. For this reason, the house is quite durable. The structure is not subject to deformations and can freely "work" in bending.

Important. Despite the fact that the material consists practically of sawdust, it is not able to react to the effects of fire. The reason for this is cement.

Sawdust concrete does not rot, and insects will never start in it. This means that the house will last forever even without additional cladding.

Sawdust concrete is an environmentally friendly and promising building material. The construction of houses from sawdust concrete is experiencing a rebirth, because the production of such blocks began a century and a half ago. Some developers believe that wood concrete is unreliable, but this statement is fundamentally wrong: in Western Europe buildings made of similar material have already celebrated their 300th anniversary, and in the USSR, some houses did not stand even for 50 years. The conclusion suggests itself: if you follow the technology of manufacturing blocks and construction, such a house is not inferior in strength and durability to brick counterparts.

What is sawdust concrete?

The composition of sawdust concrete includes cement, wood waste, sand, water, binder particles. Since the bulk of the block is chips, the product is lightweight and at the same time high strength. According to GOST, wood concrete blocks should not weigh more than 20 kilograms, and their dimensions are 39x19x19 cm. Such dimensions are considered optimal for construction.

Sometimes cement is partially replaced by clay, liquid glass or lime, then the cost of the material is reduced, and shrinkage is also reduced. By changing the ratio of components, the density, porosity and strength of the material change depending on the application. Wood concrete has many advantages, of the disadvantages, only water absorption can be noted. However, if the building material is treated with a special water-repellent composition, this minus is eliminated.

Performance characteristics

• Environmental friendliness. Since wood concrete contains 70% natural ingredients, it can be argued that such blocks are safe for human health and environmentally friendly;
• Water absorption. The level of hygroscopicity of sawdust concrete is 8-12%, this figure can be reduced to 3% if the sawdust is treated with special compounds. The lower the water absorption, the greater the resistance of the material to frost. With good waterproofing, frost resistance is 100 cycles.

Comparison table of materials

• Incombustibility. Despite the fact that the main component of the blocks are chips, due to the presence of a sand-cement mixture, this material does not burn;
• Thermal conductivity. Sawdust concrete has a slightly lower thermal conductivity than porous concrete blocks. When compared with brickwork, then 40 cm of wood concrete has the same indicators as 90 cm of brick;
• Strength. In terms of properties for bending and stretching, blocks will give odds to many materials. Sawdust and additives reinforce the product, prevent it from deforming and give it resistance to impacts. The use of wood concrete is also allowed in areas with increased seismic activity;
• Ease of handling and installation. Sawdust concrete blocks are quite light in weight, they can be given any size and shape, so this is a significant material savings. Sawdust concrete is well drilled, cut, milled.

Making sawdust concrete with your own hands

For the manufacture of such blocks, you will need: Portland cement M300, sawdust or shavings, alumina sulfate or lime, mineral additives (liquid glass, ammonium nitrate, calcium chloride, sodium sulfate), water. To increase the strength of the blocks, you can add sand.

Approximate proportions:

• 1200 kg/m3 of cement;
• 1550 kg/m3 sand;
• 220 kg/m3 sawdust;
• 600 kg/m3 of slaked lime.

Water will need 250-350 liters per cubic meter (depending on how wet the original sawdust is). In dry form, cement, sand and lime are mixed, after which sawdust is added, pour water in small portions. It is possible to prepare a solution of a suitable consistency only with the help of a concrete mixer. Squeeze the mixture in your hands: if it does not crumble and water does not run out of it, then it can be poured into a mold or formwork can be made.

When choosing sawdust, give preference to softwood shavings, up to 0.5 cm in size. Spruce sawdust is best pressed, compare the degree of suitability Supplies possible according to the table.

The hardening time will also depend on the quality of the sawdust mixture. If spruce sawdust hardens in a day, then larch needs more than 5 days. The cheapest way to make sawdust less permeable is to leave it to dry in the sun, but the oxidation takes several months. The second method is the processing of sawdust with liquid glass or calcium chloride (the second is preferable). There should be no foreign impurities in the chips - roots, earth, bark, and so on.

Collapsible forms can also be made independently from the boards. To make it easier to get the frozen mixture, fill it on the inner walls old linoleum. Ordinary champagne bottles are suitable for forming voids. The larger the block, the longer it will dry. After about 24-28 hours, the blocks can be pulled out of the matrices and dried in the shade for another two weeks. In order for the material to dry evenly, it is periodically moistened or covered with a film.

Building a house from sawdust concrete

After making sure that the wood concrete blocks have hardened sufficiently, you can begin construction. In the blocks, you need to make channels for ventilation or a chimney in advance. To protect the structure from moisture, the base is lined with brick or other moisture-resistant material. The cornice should protrude beyond the wall by at least 50 cm.

Since the blocks do not weigh that much, you can make an ordinary tape shallowly buried foundation (60-120 cm). At a height of approximately 0.5-0.7 meters, brickwork is made. With the help of ruberoid or bituminous mastic it is necessary to perform waterproofing, after which the base is sprinkled with a layer of sand (at a distance of up to a meter) and insulated.

For masonry use special glue or sand-cement mixture. Layer thickness - no more than 8 mm, otherwise the heat-insulating properties of sawdust concrete will be reduced to "no". Masonry technology is no different from brick. After installing the block, be sure to check the level, add or remove excess glue. The rows are made with dressings, after every 3-4 rows a plastic or metal mesh is placed.

We install additional supports above the door and window openings - wooden bars or metal channels. With the help of brackets on the last blocks, we strengthen the Mauerlat, after which it is possible to carry out the installation of the roof.

Exterior wall decoration is varied: from ordinary plastering and subsequent painting to laying in one brick or siding. Subject to the norms and technologies, you will receive a strong and durable building that will delight you for many years!