Sawdust - the material is far from new, the first attempts to build houses from it were made almost half a century ago. The combination of materials from which sawdust concrete is made allows the creation of universal blocks that differ in attractive qualities for builders and for owners of a house under construction.

Content:

1. Sawdust and cement blocks - what is this building material
2. What are the qualities of sawdust concrete
3. How to make sawdust concrete blocks video video
4. House of sawdust concrete - how to calculate the number of blocks
5. Features of building a house from sawdust concrete blocks
6. What foundation will you need to build
7. What solution is used for laying sawdust concrete
8. Masonry
9. Exterior and interior wall decoration

Sawdust and cement blocks - what is this building material

In most cases, sawdust concrete blocks of their own manufacture are used in the construction of all kinds of farm buildings or one-story houses. The cost of such blocks is not high, because for their preparation quite affordable materials are used:

• waste products from wood processing (sawdust),
• sand,
• water and cement.

The presence in the blocks of a large number of sawdust provides its specific lightness, the strength of the blocks provides cement.

According to GOST standards, the dimensions of the blocks should be 190x190x390, the weight of each of them should be about 20 kg - such material parameters are most optimal when erecting the walls of residential and utility buildings.

There are voids inside the blocks; for their formation, rectangular or cone-shaped inserts are laid in the matrices. To further reduce the cost of sawdust concrete, part of the cement is replaced with clay, liquid glass or lime, such changes in the composition make it possible to reduce the shrinkage of the mixture during the hardening process.

Sawdust concrete proportions of components may have different - they are calculated depending on how the blocks will be used - for the construction of load-bearing walls or partitions. By properly regulating the ratio of components in the mass, it is possible to change the indicators of porosity, strength, density of blocks to the right degree. In order to rationally use sawdust concrete blocks, you should carefully study all of their positive characteristics and disadvantages, as well as the nuances of construction work.

What are the qualities of sawdust concrete

Many of the declared qualities of the material fully comply with the modern requirements of the construction industry:

• low weight can significantly reduce the cost of the installation of a monolithic concrete foundation,
• the use of exclusively natural products in production ensures environmental friendliness,
• processing waste wood used in the production of blocks allows you to reduce the percentage of moisture and bring it to 10-12%, if necessary, to lower rates, about 3%. Naturally, such a low humidity indicator will contribute to increased frost resistance.

Since the filler from waste wood is hidden in a cement-sand mixture, the material can be classified as non-combustible, even when exposed to fire it will not support combustion, the limit of resistance to open fire is about three hours. The sealed structure of the blocks contributes to the natural attenuation of the fire.

The structure of the material allows it to compete with porous concrete blocks occupying a leading position in construction. The sawdust concrete wall 0.4 m thick has the same heat-saving qualities as a brick one, but 0.9 m thick, it is provided with wood components - heat insulation by sawdust of the walls of the house - it is quite effective and finds application in the construction of green housing.

Sawdust-concrete blocks are not inferior to foam concrete and aerated concrete competitors in terms of tensile or bending loads. Fiber additives and natural wood waste present in the composition of the material play the role of reinforcing components and give it resistance to loads in the form of shock or deformation. The material is suitable for construction in an earthquake hazardous area.

Work with the material is facilitated by the simplicity of its processing, the ability to give it the necessary dimensions and shape without any problems, this significantly reduces the consumption of blocks. Such material as sawdust concrete, the reviews of builders deserves the highest: blocks from it are easy to mill, cut with a hacksaw, drill or nail.

As a significant drawback, hydrophobicity, i.e. walls made of sawdust concrete will require the installation of a vapor barrier system from the inside and the outside. This fact affects the cost of construction and increases its complexity.

How to make sawdust concrete blocks

It is not difficult to make sawdust concrete with your own hands, but a certain technology will have to be observed during manufacture. No special tools are required for work.

As a filler in the manufacture of sawdust concrete, you can use waste from coniferous wood, both sawdust and small shavings are suitable, ideally if their ratio is equal. Using fresh wood is not recommended, it is advisable to withstand it for about 3 months, in order to speed up the drying process, they will need to be mixed periodically. Sawdust should be clean, free of dust and impurities of clay, soil, etc. The chips should be sieved through a sieve with a 10 mm cell, then 5 mm, this will help remove too large fragments from it. To make the blocks of appropriate quality, it is advisable to use a concrete mixer.

Of the starting materials, brand 400 cement will still be required. Bonding additives, which can be aluminum sulfate, hydrated lime, calcium chloride, should be used in a volume of 2 to 4% by weight of cement. Water should be added in an amount that allows you to get a plastic mixture. When compressing a small amount of the resulting solution, moisture should not be released in the hand, however, the mixture should not be friable.

The prepared mixture can be laid in forms made of boards, the inner surface of the walls of the form is best upholstered with linoleum - it will be easier to remove the finished blocks. You can seal the spilled mixture into the mold manually or mechanically. To form voids, you can use champagne bottles.

In the manufacture of molds, it should be taken into account that an increase in their size will prolong the drying of the blocks, this leads to the presence of wood fragments in the material. This behavior of wood also limits the possibility of building monolithic houses from sawdust.

It takes a day to harden the material, then the blocks are carefully removed from the matrices and dried in a place protected from the sun. In order for the drying to occur evenly, periodically wet the blocks or cover them with a layer of plastic film.

House of sawdust concrete - how to calculate the number of blocks

The calculation of the number of blocks is not difficult, first we determine the perimeter of the structure, multiply it by the planned wall height, as a result we get the total wall area. Further, taking into account the thickness of the walls, the number of blocks that will be required for the construction of 1 sq m of the surface is calculated. For example:
  masonry thickness of 19 cm will require the use of 12.5 blocks per square meter,
  if the masonry should have a thickness of 0, 39m - 25 pieces will be required,
  for the construction of walls with a thickness of 0.6 m - 37, 5 pieces.

To get the exact number of blocks, the area of \u200b\u200bwindow and door openings should be subtracted from the obtained total area, then the remaining sq.m should be multiplied by the calculated number of blocks required by 1 sq.m. However, builders do not recommend subtracting the area of \u200b\u200bthe openings - they will automatically eliminate the need to include a safety factor in the calculations.

Similarly, the number of blocks for internal walls, which are partitions or supporting structures, is calculated.

Features of building a house from sawdust concrete blocks

The calculation of the required wall thickness is made taking into account the average temperatures that are observed in the area in the winter months. The recommended thickness of the internal load-bearing walls is 300 mm.

To give the building special strength during masonry, reinforcement of horizontal joints with a mesh with a cell from 50 to 100 mm, with a wire diameter of 3 to 6 mm is used. To extend the life of such structures, it will be necessary to clad the walls, the plastering of the surface also gives a good result.

When designing a house made of sawdust concrete, it will be necessary to think over the location of communications and provide for openings on the drawing for the output of ventilation, chimney channels, and other engineering systems.

Raw blocks cannot be used for masonry walls, it is recommended to wait for them to dry completely. The masonry technology itself will not be any different from that recommended for the construction of walls from foam blocks.

If sawdust blocks are bought ready-made, then pay attention:

• on the cement grade used in their manufacture, a higher one provides the block with greater strength,
• they check whether it is possible to extract a single chip from the material - if you can do it with ease - you should doubt the quality of the proposed blocks,
• blocks should be chosen with a geometrically correct shape - it will contribute to less waste adhesive solution.

Moisture-resistant materials should be used for building the foundation of the house, the creation of a foundation waterproofing system should not be neglected. Experts recommend calculating the roof so that its lower edge extends no less than 50 cm beyond the outer side of the walls - in this case, rain will not fall on their surface.

What foundation will you need to build

Since sawdust concrete is lightweight, it is possible to do with the construction of a shallow foundation. But it can be built on all soils, except those prone to strong expansion. Bored piles or reinforced concrete tape with a width of 40 to 60 cm can be used as the foundation foundation, the foundation laying depth can be from 0.6 to 1.2 m. In order to protect sawdust from moisture, it is recommended to expose a brick base with a height of at least 0, 5 m

For waterproofing the foundation, the need for which was already mentioned above, you can use traditional materials: roofing material, bitumen mastic, etc. The base of the house is recommended to be insulated and sprinkled with sand at a distance of at least 0.5 m - this will be enough to prevent contact of the foundation with the ground.

What solution is used for laying sawdust concrete

Laying sawdust concrete slabs can be done in two ways:

• on a normal cement-sand mortar, while it becomes possible to correct the unevenness of the blocks, but a thick layer of the solution can contribute to the formation of cold bridges; when performing masonry, it will be necessary to moisten the surface of the blocks;
• on glue intended for laying cellular materials containing special additives to reduce heat loss through the joints. The maximum allowable adhesive layer is indicated on the package, in reality it can reach 6 mm, its maximum allowable thickness is 8 mm. Based on this fact, it is easy to conclude that glue is rational to use only if blocks with the correct geometric shape are used.

Masonry

They start work from the angle that has the highest level, for a tub of the first row it is best to use a cement-sand mortar - it will create a horizontal base for laying all subsequent ones. Then, the blocks are laid at the remaining corners, using levels to check the correctness of their level. Next, between the blocks you should pull the cord, it will serve as a guide for laying the remaining blocks of this row. Application of the solution is carried out on the lower part of the block and side.

If in a row you need to lay a half or a quarter of a block, then it is cut off with a hacksaw, when calculating its size, the thickness of the vertical joints is taken into account. The correct masonry of each block should be checked for verticality and horizontalness - you can correct the position of the fragment by adding or removing a certain amount of adhesive mixture or mortar. To apply the adhesive, use a spatula or trowel.

Masonry should be performed with dressing - the formation of vertical seams between the blocks should not be allowed. Laying every 3-4 rows of metal reinforcing mesh will increase the strength of the walls.

Window and doorways in the upper part are made out with jumpers, which can be used as thick beams or metal channels. In blocks located above the jumpers, grooves of the appropriate section should be prepared in advance. The jumpers should extend beyond the edges of the openings by at least 0.5 m on each side.

After laying the last row, the Mauerlat is installed, then the rafter system is assembled and the crate is packed under the roof covering. All wooden parts that were used during construction are recommended to be treated with antifungal primers.

Exterior and interior wall decoration

Since the wall from sawdust blocks will not shrink, you can proceed to its decoration immediately after the completion of the laying of the walls. As external and internal finishing, plastering can be used, while the high adhesion of sawdust itself allows you to perform this work without prior preparation. For plaster, a cement-sand mortar is used, impose it with a layer of 2 cm.

To make the plaster more reliable to the plastered surface, a metal mesh is initially fastened with screws or nails.

For wall sheathing, you can use a block house, siding, lining, you can build a ventilated facade or perform finishing brickwork. The materials are mounted on a flat surface without preliminary preparation, if the walls are uneven, the construction of the lathing will be required.

The plastered surface can be covered with a layer of two-component acrylurethane-based paint - it:

• protects walls from moisture,
• give them an attractive look
• will make their cleaning easier and more convenient.

For plastering the inner surface of the walls, you can use perlite mixture, it is environmentally friendly, it copes well with the task of wall insulation. After applying the plaster, the walls can be wallpapered or painted.

An important condition for long-term operation of the house is to maintain the optimum level of humidity in the room - it should be less than 75%.

Of course, the choice of material for building a house or any other construction depends entirely on the developer and his financial capabilities. The use of sawdust concrete, moreover, made with one's own hand will significantly reduce the cost of construction. But this choice should be taken very seriously - during the entire period of operation, such houses will need special care, and the construction itself must be carried out in strict accordance with the recommended technology for laying and finishing work.

Author: Sergey and Svetlana Khuentsov

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