How to choose a quality product
The Russian market is filled with fake and low-quality products, so it is very important to choose the right boards and blocks from wood chips and cement
Therefore, we recommend paying attention to:
- the appearance of the material;
- certificate of conformity;
- test report;
- reviews of those who already live in houses from the material of a particular manufacturer.
All products must be completely identical in size and shape, if at least one item differs in size and shape from others, then it is better to refrain from buying. Most likely this batch of products is made on low-quality equipment.
Be sure to ask the seller or manager to show you a certificate of conformity and a test report.
If these documents are not available, most likely you have before you the products of one of the underground enterprises, therefore the composition and real characteristics of the blocks or plates are not known to anyone.
In addition, ask the seller or manager for the addresses and phone numbers of those who have already bought a SCH or SCH from them.
Those who produce quality products never hide the contact details of their customers, because their homes are the best advertisement for the company's products. If they refuse to provide you with the addresses or phone numbers of those who purchased the company's products, then refuse to purchase.
SCCB
The installation methods and suitable adhesive are also completely identical. However, due to the high cost of obtaining chips, conventional blocks are not widely used, which cannot be said about fixed formwork blocks.
They are a finished cell with outer and inner walls, as well as transverse partitions. Styrofoam is often glued to the inside of the outer side, which is held there much stronger than on fixed sheet formwork.
Indeed, in addition to the high strength of the block itself, staggered laying also has an effect, due to which each piece of foam is securely fixed by a jumper both on its own row and on the next one.
Blocks of fixed formwork Durisol are made using the same technology as conventional wood concrete blocks, the only exception is the shape of the matrix and punch.
Properly manufactured blocks are equipped with locks both on the upper and lower sides, and on the ends, so that when assembling the formwork, the individual parts are securely connected to each other.
Prices
We have prepared a table that includes products from various manufacturers:
| Type and name of material | Dimensions (length, height, thickness in mm) | Price in rubles per unit | Manufacturer or seller | Website of the manufacturer or seller |
| Plates | ||||
| SV-35 | 2000x500x35 | 375 | SV-Invest | zsmsvinvest.ru |
| SV-U-135 (with foam) | 2000x500x35, PBS-S-35 foam thickness 100 mm) | 826 | ||
| SV-35 | 2000x500x35 | 370 | Eco house | eko-dom123.ru |
| SV-P-105 (for partitions and internal walls) | 2000x500x105 | 1200 | ||
| SV-U-135 (with foam) | 2000x500x35, PBS-S-35 foam thickness 100 mm) | 810 | ||
| WCS-35 | 2000x500x35 | 340 | PG-STROM Group, CJSC | pgstrom.stroynet.ru |
| Blocks | Dimensions (length, height, thickness in mm) | Price in rubles per unit | Manufacturer or seller | Website of the manufacturer or seller |
| DM 22/15 | 500x250x220 | 145 | Dobrynya | dspb.ru |
| DM 25/18 | 500x250x250 | 180 | ||
| DSs 30/15EA | 500x250x300 foam thickness 5 cm | 300 | ||
| DM 22/15 | 500x250x220 | 138 | CityStroy SPB | opalubka-stroy-spb.ru |
| DM 25/18U | 500x250x250 | 171 | ||
| DSs 30/15EA | 500x250x300 foam thickness 5 cm | 285 | ||
| DM 25/18 | 500x250x250 | 140 | StroyOpt | pro100stroyka.ru |
| DSs 30/15EA | 500x250x300 foam thickness 5 cm | 255 |
Several fertilizer recipes
Sawdust in its pure form is used only for filling paths in order to retain moisture and stop the development of weeds. In other cases, the preparation of raw materials is required.
In order for the sawdust in the garden to become useful, they need to rot. For the desired condition, they will have to lie down for at least 10 years in a heap, while the bacteria process the wood into a useful substrate. You can speed up the process - you need to make compost from sawdust. In combination with manure and additional additives, the fertilizer ripens faster due to thermoregulation in the desired range and maintaining a sufficient level of humidity.
We offer several recipes for making fertilizer from sawdust, which are used by gardeners throughout the country. It is recommended to bookmark from the beginning of summer as the necessary material arrives.
Recipe 1: wood and ash
Lay down:
- Wood sawdust - 200 kg;
- Urea rich in nitrogen (up to 47%) - 2.5 kg per pile;
- Ash necessary for alkalization of the soil - 10 kg;
- Water - 50 liters;
- Grass, food waste and drains - up to 100 kg.
Shavings and grass are laid in layers, ash is added and the “pie” is poured with urea dissolved in water. You can cover the pile with polyethylene film, but small pores should remain on the surface: this way the temperature and humidity level will be optimal, and oxygen will remain available.
Recipe 2: Enriched with organics
For poor soil that requires a significant dose of fertilizer, prepare this compost from sawdust:
- Wood waste - 200 kg;
- Cow dung - 50 kg;
- Fresh cut grass - 100 kg;
- Organic waste (food, feces) - 30 kg;
- Humates - 1 drop per 100 liters of water (no more).
When this fertilizer ripens, a significant amount of nitrogen is released.
Fertilizer from fresh sawdust
As already mentioned, fresh sawdust does not benefit the soil as a fertilizer for the garden. If you have not done composting in advance, but it is necessary to saturate the soil, use a sawdust mixture with the following additives per bucket of wood chips:
- Ammonium nitrate - 40 g;
- Granular superphosphate - 30 g;
- Slaked lime - 120 g (glass);
- Calcium chloride - 10 g.
The mixture must be infused for 2 weeks. To do this, spread polyethylene on the street and sprinkle the ingredients on it.
Mix, leave to isolate the necessary elements and carry out chemical reactions. After that, add the resulting mixture to the soil when digging the beds. The earth will receive a sufficient dose of ammonia, the acid-base balance of the soil will be leveled, the release of useful substances will occur immediately after the first watering. Fertilize the soil should be in the amount of 2-3 buckets per 1 square meter of land. This procedure contributes to the natural loosening of the soil.
Comparison with other types of permanent formwork materials
The main competitors of the Velox ShchTsP when creating fixed formwork are:
- DSP;
- Styrofoam;
- glass-magnesite sheet (SML);
- Durisol blocks.
If we compare ShTsP and TsSP, then both materials are the same in all basic characteristics, because the only difference between them is the amount of wood waste.
The exception is chip-cement slabs made with the addition of liquid glass - they are much inferior in vapor permeability, due to which the walls of the house cease to transport excess moisture to the street. The addition of styrofoam exacerbates this situation, causing the home's ventilation requirements to skyrocket.
The main advantage of foam plastic is its low price and good thermal insulation properties, however, due to its low strength, such formwork must be sheathed with some kind of sheets, at least from the inside.
LSU is somewhat denser than SCHP, and is also supplied in sheets 2–2.5 m long and 1.2–1.25 m wide, so it is noticeably harder to work with it. In addition, you will have to use not only overhead clamps, but also fasten them with through screeds, which, after the concrete has hardened, will have to be covered with additional finishing, because if they are cut off, then there is a high probability that the LSU will peel off from the concrete.
Despite the fact that Durisol blocks are made of the same material as Velox plates, their application and influence on the speed, and often the result of construction, are very different.
Finished blocks do not need fixing jumpers, because they themselves are such jumpers.
In addition, the peeling of the foam glued into them does not lead to problems, because it is securely pressed from all sides.
Therefore, the construction of formwork Durisol requires much less time and materials.At the same time, according to the main operational characteristics, Velox plates and Durisol blocks are completely identical, because they are made of the same material.
Other options for concrete panels
In addition to traditional cement-based concrete, other types of concrete are also made from chips:
- plaster;
- clay;
- lime.
However, their bearing capacity is much lower than that provided by the use of cement. Therefore, alternative types of chip concrete are used only as an insulating material. Another difference is the absence of sand, because sand increases the strength of cement stone, but has little effect on other types of binders.
In addition, alternative types of chipped concrete are highly sensitive to moisture and water, so they can be used either indoors (insulation of floors and ceilings) or covered with a very high-quality finish that protects from precipitation as much as possible.
Calculation of the necessary materials for the preparation of blocks from chips and concrete
To obtain high-quality concrete, it is important to observe not only the proportions of the initial components, but also the entire procedure, otherwise the strength of the material will be lower than expected. Also, a violation of the procedure will lead to an increase in the ability to absorb water, which will reduce the life of the concrete structure.
Here is the procedure that is applicable for the preparation of chip concrete for any purpose:
- Dissolve freshly slaked lime in water (1 kg per 20 liters of water) and soak chips in this milk. Soak small chips (thickness 0.1 mm or less) for a day, medium (thickness over 0.2 mm) - 48 hours, large (thickness 0.4 and more) - 72 hours.
- In a concrete mixer, mix cement, sand and quicklime in the right proportions.
- Catch the shavings from the container with milk of lime and let it drain for 10-15 minutes, then pour the right amount into a concrete mixer and mix thoroughly.
- Prepare water, for this, add superplasticizer to it in the amount of ¼ of that recommended in the instructions for it. You also need to add hydrophobic additives, for example, Siloxyl (instructions for use on the package). If you are making insulating concrete, then also add saponified resin foam or other air-entraining additive (a foam generator is required). At the same time, follow the instructions on the packaging with the reagent strictly.
- Add the right amount of water (take into account the moisture content of the sand and the milk of lime in the chips, so reduce the amount of water by 2-5%) and mix thoroughly.
- Distribute concrete into molds.
- If you did not have time to work out all the concrete in 5 minutes, then mix again.
Here is the calculation of materials for the manufacture of concrete particle boards for various purposes:
| Number of components in kg (for water in liters) | |||||
| Purpose | Cement | Sand | Lime | Shavings | Water |
| warming | 10 (M400) | 2 | 8 | 100 | 3 |
| Insulating and for non-load-bearing walls of non-residential buildings | 10 (M400) | 10 | 10 | 100 | 3 |
| Load-bearing walls of non-residential structures or non-load-bearing walls of residential | 20 (M500) | 50 | 20 | 100 | 9,5 |
| Bearing walls of residential one-story houses | 40 (M500) | 100 | 50 | 100 | 20 |
| Bearing walls of two-story houses | 40 (M500) | 100 | 50 | 50 | 19 |
Common manufacturing mistakes
Negative reviews about chipboard that can be found on the Internet are most often associated with mistakes made during the preparation or use of this material.
Next, we will talk about the most common of them.
Ignoring superplasticizers and hydrophobic additives
Quite often, users ignore and do not use superplasticizers.
These substances reduce the amount of water required to create a solution of the desired viscosity, thereby increasing the strength of the hardened concrete.
The addition of superplasticizers is desirable when pouring blocks, because it increases their strength, and is necessary when pouring monolithic walls.
Concrete with this additive is more plastic and easier to fill the formwork with the same amount of water.
By ignoring hydrophobic additives, the amount of moisture that enters the wood increases, so even filling the pores with minerals cannot reduce water absorption to a safe level. Often, additives are abandoned because they are afraid of reducing vapor permeability, but they do not affect this parameter.
Steam moves through the particles of cement stone at a very low speed, so the vapor permeability of chip concrete is always lower than this parameter of wood and is on the same level as brick or concrete. The addition of hydrophobic additives reduces vapor permeability by 2-5%, so it does not have any serious effect.
Chip selection and neglect of soaking
A common omission is also the wrong choice of chip type. It is a mistake to use shavings of "sweet" wood species. Such species include birch, maple, willow, alder, fruit trees.
Lime partially neutralizes the negative effects of sugars, but there is too much glucose in sweet rocks. But there are few sugars in conifers and lime almost completely blocks this negative effect.
In addition, the chips are not pre-soaked in milk of lime. This operation is not performed to disinfect wood waste, its purpose is to fill the pores with minerals, which reduces the ability of wood to absorb water, which means it increases:
- concrete strength;
- load bearing capacity;
- life time.
Sand and water
It is also a mistake to use smooth fine sand. The coarser the sand and the more uneven the shape of each grain of sand, the harder it is to work with it, but also the higher the strength of concrete.
After all, cement milk quickly slides off smooth sand, while on an uneven surface it lingers until it solidifies.
And an increase in the amount of water makes concrete more convenient to work with, but weakens the cement stone, resulting in a decrease in the strength of the block or wall.
Saponified Wood Foam Neglect
For insulating boards, a decrease in the thermal conductivity of cement stone is more important than some loss of strength due to the transformation of cement stone into an analog of a sponge, because these plates are not used as load-bearing elements.
The addition of foam and other reagents increases the heat-insulating properties of the slab by 5-15%, which brings it closer in terms of thermal efficiency to mineral wool and foam plastic.
Poor quality exterior finish
It is very important not to forget about the high-quality exterior finish of chip concrete. Adding hydrophobic additives and filling the channels with minerals reduces the sensitivity of the wood to water vapor, however, contact with water gives too much moisture, which impregnates the concrete and causes the wood waste to expand.
When moving from a liquid to a solid state, the volume of water increases by 11%, so the higher the humidity before the onset of frost, the stronger the impact on the cement stone during the freezing of water inside the wood.
SCHP
These materials are made from wood concrete, often adding liquid glass to it. In most cases, the density of the finished board does not exceed 800 kg/m3, so it has high thermal insulation properties and good strength.
Because chips are much thicker than chips, it is difficult to make thin sheets from them, so in most cases the minimum thickness is 35 mm. This is too much for exterior or interior decoration, but ideal for fixed formwork.
The Velox company was the first to manufacture and use such slabs in the middle of the 20th century, therefore, since then, SCHPs intended for external formwork have been called that.
Due to the use of natural coniferous wood chips, the company widely advertised its products as a new word in construction and an environmentally friendly, safe material in all respects.
Some manufacturers glue insulation to the plates, but this design causes a lot of criticism from builders.
After all, manufacturers use cheap adhesives, or even just cement milk, so reliable gluing does not work.
As a result, over time, the foam or other insulation moves away from the slab and the formwork, which does not have direct contact with concrete, begins to move, which leads to cracks in the finish and drafts.
For this reason, to create a permanent formwork, material 60–85 mm thick is often used, because when such plates are installed on both sides of the wall, their total thermal conductivity is comparable to foam plastic 10 cm thick.
Such a wall is more than enough even in the northern regions, with the exception of the Far North, but there it is possible to increase the thickness of the wall by 1.2–1.5 times.
With sufficient thickness (usually 60–80 mm), such slabs can be used as partitions and interior walls. Their use in this capacity is completely identical to the use of DSP, because the only difference between these materials is in the method of obtaining wood filler and its dimensions.
The manufacturing technology of chip-cement boards is completely identical to that used in the production of CSP.
The only exception is the method of obtaining wood filler.
For cement-bonded material, waste from machine planing of wood is used, and for chip-cement parts, the filler is made on chippers or special shredders.
For more information about such equipment, see these articles:
- Production of wood shavings;
- Chip cutters.
The use of concrete particle boards
Due to the low compressive strength, this material is not used to create the load-bearing walls of multi-storey buildings. Even two-story construction is permissible only with wooden floors, and even then, the material will have low thermal insulation properties.
However, this material is used for:
- creating walls of low-rise buildings with low load;
- insulation;
- filling the space between reinforced concrete load-bearing columns.
Create walls for low-rise buildings
Despite the fact that GOST R 54854-2011 does not allow the use of chipped concrete for the construction of residential buildings, houses have been made of it for many decades, and it has been used for the construction of outbuildings since the middle of the last century.
Such a period is sufficient to conclude that when:
- correct selection of components;
- competent drafting of the project;
- properly selected finishes;
- keeping technology,
houses with a height of 1-2 floors are quite durable and warm.
However, it is advisable to install such houses only in regions with:
- stable climate;
- little rainfall;
- slight diurnal temperature fluctuations.
Violation of any of these points reduces the life of the walls. An unstable climate, as well as heavy rainfall, mean sharp changes in air humidity, and hence the moisture content of wood in the composition of chipboard.
Changing the size of the chips, caused by changes in humidity, leads to a change in the size of wood waste. When the wood fills with water and grows in size, it easily breaks the cement stone, which leads to weakening of the chipped concrete.
To do this, liquid glass and other hydrophobic additives are added to the concrete composition, which prevent the absorption of water by wood, thereby reducing the amplitude of changes caused by moisture swelling and shrinkage of wood.
Warming
For insulation, a material with a minimum content of cement and sand is used, in addition, it does not experience the loads that are transferred by blocks of wood shavings and concrete in load-bearing walls.
Therefore, a slight decrease in strength caused by swelling and shrinkage of the chips does not affect the thermal insulation capacity.
Such a heater cannot be left open, because it strongly absorbs moisture not only from rain, but also from the air.
The addition of liquid glass does not affect the thermal insulation properties, but reduces the ability of chip concrete to transport moisture from the walls to the atmosphere, reducing it in this parameter to the level of a clay brick.
Filling the space between reinforced concrete columns
In frame houses with reinforced concrete columns, different types of lightweight concrete, including chip concrete, are used to fill the space between the columns. In terms of heat-insulating abilities with equal density, it is surpassed only by polystyrene concrete, and other types of lightweight concrete are similar or inferior to chip concrete.
However, even in warm regions, such houses need to be insulated, because the thermal conductivity of reinforced concrete is very high, therefore, without insulation, cold bridges will appear in place of the supporting columns.
