How to plaster walls made of arbolite blocks from the outside. Materials and technologies for exterior finishing of a house made of wood concrete

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Due to arbolite blocks have a porous structure, their surface strongly absorbs moisture, and this, in turn, complicates the plastering process. However, plastering wood concrete is a feasible process for self-execution, you just need to follow the existing technology.

Therefore, if you are wondering how to plaster arbolite house inside and out, then this article should certainly help you in this difficult process.

And, first of all, you should consider questions regarding the composition of the plaster for wood concrete. The fact is that, as mentioned above, wood concrete absorbs moisture well, so the compositions for plastering it require slightly different compositions. And to be more specific, the preparation of the base of the walls before plastering the wood concrete is a little different.

Wood concrete walls can be plastered using various building mixtures, here is a list of just a few of them:

Cement plaster, the basis of which is sand and cement in a ratio of 3 to 1. When used cement plaster for wood concrete, a layer thickness of 2 or more centimeters is allowed.
Gypsum plaster, used for finishing interior walls from wood concrete.
Lime plaster, consisting of lime, is also used for plastering wood concrete.

Choosing one or another mixture for finishing arbolite walls, you can begin this truly difficult process. What should you consider while doing it?

The porosity of wood concrete is both a plus and at the same time a significant minus. The advantage is that any material adheres very well to such a surface. plaster mortar. The disadvantage is that moisture penetrates very quickly into the pores of the material, and mortar Accordingly, it dries in a matter of time.

A primer or generous wetting of the surface of wood concrete walls before plastering them can help solve this problem.

In general, plastering wood concrete is practically no different from finishing concrete or brick walls. First, the surface is prepared, then follows (in some cases, reinforcement can be abandoned).

First, it is recommended to apply the so-called initial layer of plaster - spray. Accordingly, special ones are used to implement this work. Well, after this the walls are covered with a second layer of plaster, and then last layer“covering” with subsequent troweling of the surface.

When building walls from wood concrete blocks, you must remember that wood concrete absorbs water very quickly. Therefore, before laying, the blocks must be wetted to avoid drying out of the mortar, which leads to cracks. This is especially true in hot and dry weather. Recommendeduse a “warm” solution based on perlite to avoid “cold bridges”.

One of best finishes arbolite walls outside, in our opinion, is a ventilated facade. This is, on the one hand, protection of the material from external influences and, on the other hand, an opportunity for excess moisture not to accumulate inside, but to pass freely through the walls, leaving them dry.

The ventilated facade can be either hinged or brick with a gap of about 5 cm.

The most popular finish for wood concrete is plaster. Nowadays plaster with perlite is very popular, which not only protects against blowing and improves appearance, but also provides significant insulation to the walls.

If you decide to make masonry mortar and plaster with perlite yourself, it is better to wet the perlite before mixing. Wet perlite is much easier to apply - it does not fly apart. In addition, perlite first absorbs water and then releases it, which creates additional difficulties when preparing a solution with dry perlite.

FINISHING OF ARBOLITA PRODUCTS

Finishing wood concrete products is one of the most important technological operations. The durability of the structures themselves, as well as the buildings that are built from them, largely depends on the quality of the finishing. Field surveys of buildings for various purposes conducted in various climatic zones ah of our country, showed that in structures with a good protective finishing coating, wood concrete has a stable humidity not exceeding 12%, and the buildings are located in good condition. And vice versa, with poor-quality protective and finishing coatings, a large number of cracks appear on the surfaces of structures, the textured layer peels off, and the structures themselves warp. The humidity of wood concrete in such structures, regardless of the orientation of the walls and climatic zones, is usually high (more than 30%). At such humidity, the strength indicators of wood concrete sharply decrease, its deformability increases, its thermophysical properties deteriorate and conditions are created for its biological damage.

Due to the fact that wood concrete has a large-porous structure and high sorption moisture content of the surface, structures made from this material must be covered with protective and finishing coatings. The type of protective and finishing coating is determined in each specific case depending on the purpose of the building, its location, existing factory technology and economic feasibility.

Cement-sand mortars, concrete, slab cladding and paint coatings. To date, the finishing of wood concrete at some operating enterprises is carried out by the method of textured cement-sand layer 15-20 mm thick and, as a rule, one side is finished.

At several enterprises of the USSR Ministry of Forestry, bilateral invoicing is carried out. Most often, buildings erected from arbolite structures are finished with construction site. In this case, walls made of arbolite structures are plastered cement-sand mortar, then whitewashing with added pigments is used on the outside (less often, painting with paint and varnish coatings), and on the inside, depending on the purpose of the building, wallpaper is pasted or painted with various paint compositions. However, the quality of such finishing is not always high.

In order to protect wood concrete in structures from moisture, we conducted research to find effective protective and finishing coatings. For the research, protective paint and varnish coatings were selected that have proven themselves well during operation with cellular concrete. These are TsPKhV, KCh-26, VA-27A paints, latex-organosilicon whitewash, lime-silicon organic whitewash, etc.

The quality of the finish was assessed by the frost resistance of the protective and finishing coatings and the wood concrete protected by them, by their resistance to alternate moistening and drying, and by the reduction in the adhesion strength of the textured layer and the wood concrete from the indicated influences. As a result of the research, the following was established:

The best resistance to frost was shown by coating with cement-perchlorovinyl paint on both the textured layer and the wood concrete;

paints KCh-26 and VA-27 A, not intended for external coatings, but which have shown sufficient resistance to frost, can be recommended for finishing and protecting the internal surface of enclosing structures of unheated buildings with wet operating conditions;

Latex-silicon whitewash recommended by the “Guidelines for the design and manufacture of wood concrete products” can also be used for the protective and finishing coating of wood concrete structures. However, it should be noted that during its preparation and application difficulties arise due to the reaction that occurs between the components of the protein and its separation. At the same time, it was noted in the studies that after 45 cycles the formation of small cracks. The formation of cracks in the coating with KCh-26 paint began after 35 cycles, and the latex-silicon paint began to peel off in places from the textured layer after 40 cycles.

Thus, the most durable in this regard is coating with cement-perchlorovinyl paint on both the wood concrete and the textured layer.

The results of studies of the frost resistance of textured layers with various chemical additives and protective finishing coatings also showed the following:

a decrease in water absorption through the textured layer helps to increase its frost resistance;

The studied additives introduced into the composition of the textured layer have positive impact both to reduce water absorption through the textured layer and to the adhesion of the textured layer to the wood concrete; best results obtained by introducing polyvinyl acetate emulsion, calcium nitrate and GKZh-94 into the textured layer;

During the studies, an increase in the adhesion forces of the textured layer to the wood concrete was observed after testing the samples for frost resistance, which is probably explained by the good waterproofing properties these coatings, causing low water absorption of the samples. This allows us to recommend such compositions for implementation in construction practice;

the adhesion strength of the textured layer to wood concrete decreases when moistened and dried, like the strength of wood concrete, but more intensively. This is apparently explained by different values of moisture deformations of the textured layer and wood concrete and stress concentration in the boundary zone;

All protective and finishing coatings applied to the textured layer increase frost resistance and resistance to alternate wetting and drying of the textured layer compared to control samples without coating in proportion to their reduction in water absorption through the textured layer.

The most effective coatings turned out to be latex-organosilicon whitewash and TsPKhV paint, less effective - coatings with calcium stearate and lime-organosilicon paint. Good protection from moisture is ensured by treating the textured layer with water repellents and polymer materials(GKZh-10, PVA, latex SKS-65GP).

As studies have shown, coating the surfaces of wood concrete structures significantly increases the durability of this material and gives the products and buildings constructed from them a beautiful appearance. However, these types of finishing have not yet found widespread use in the production of wood concrete, as they are scarce and quite expensive. Taking into account all these factors, we proposed the protection and finishing of wood concrete with concrete layers with the simultaneous installation decorative covering from ceramic breccia.

From the book by A.S. Shcherbakov, L.P. Khoroshun, V.S. Podchufarov “Arbolite. Improving quality and durability" 1979

Arbolite blocks- This construction material, for the production of which crushed waste from woodworking and sawmilling, water and high-quality cement are used. A small percentage of chemical additives is allowed. Depending on the components in the composition, they are distinguished different types finished products:
– made from sawdust.

To give them greater strength, manufacturers increase the mass fraction of cement. Due to this, strength increases, but the heat efficiency of the finished product decreases:

Made from wood chips. A large percentage of wood chips ensures high elasticity and strength of the blocks.
From a mixture of wood chips and sawdust. This type has average strength and thermal conductivity.

Based on their purpose and application, finished products can be divided into the following groups:

Structural– for the main masonry of walls (walls), construction of partitions, installation of armored belts, use as lintels over windows and doors.
Thermal insulation– for insulation of floors and walls (arbolite thermal panels).

Specifications

Wood concrete is produced in the form of gray wall blocks measuring 500x300x200 mm and partition blocks measuring 500x150x200 mm. The thermal panel has dimensions of 820x620x80 mm.

Here are some basic specifications wood concrete and compare them with other building materials:

The average density is 650 kg/m3, and for structural blocks it is higher than for thermal insulation blocks, and amounts to 700-750 kg/m3. The density of wood concrete is higher than that of wood and aerated concrete, but less than that of brick and expanded clay concrete.
The material has low thermal conductivity - 0.12 W/(m x °C). Of all the building materials, only natural wood has the lowest thermal conductivity.
The compressive strength of the material is 0.5–8.5 MPa. For aerated concrete, the tensile strength is 2.5–15 MPa, for ceramic brick 2.5–25 MPa.
Frost resistance indicator – 25–100 cycles. It is the largest among all building materials, with the exception of wood.
Water absorption of wood concrete is 40–85% by weight. This is the maximum figure. For other building materials, the average percentage of water absorption is 16%.
The material has a shrinkage of 0.4–0.5%.
The bending strength is 0.7–1.0 MPa. It is the bending strength that sets wood concrete apart from others cellular concrete. Under the same load, aerated concrete or foam concrete may crack, but they will not appear in wood concrete.

Advantages and disadvantages

Arbolite blocks have many advantages:

They have very low thermal conductivity, which allows the construction of objects without them. additional insulation, even in the northern regions. High heat capacity wood concrete provides savings of thirty percent of energy resources for space heating during subsequent operation.
They have high noise insulation properties. The sound absorption coefficient of wood concrete is 0.17–0.6 units, wood has a coefficient of 0.06–0.1, and brick is not higher than 0.04. This feature of the material has become particularly relevant due to the increased building density of houses at the present time.
Arbolite is an environmentally friendly material. Made of 80% wood, it does not highlight harmful substances when heated, and is safe for the health of people and animals.
Non-flammable(belongs to the group low-flammability substances), are low-flammable and low-smoke.
Not subject to cracking undemanding to transportation conditions and have high strength indicators. Wood concrete walls are very strong and reliable;
The arbolite block is relatively light in weight, which makes it possible to use inexpensive.
The blocks are very flexible due to the ability of wood chips in their composition to shrink and recover without losing their original properties.
When constructing small objects, you can not use masonry reinforcement and installation of monolithic belts.
They are not subject to rotting processes and are resistant to mold, even in conditions of high humidity. The walls of the house can “breathe” due to the porous structure and high wood content in the composition.
The material is easy to process. You can easily drive a nail or screw a screw into it, drill, saw or cut it to the desired size.
Laying a wall made of wood concrete takes much less time than when using other materials.

Of course, no building material can be ideal in all respects. And, like everyone else, wood concrete has its drawbacks:

Availability on the market large quantity handicraft products. When purchasing wood concrete, especially in the regions, there is a high probability of purchasing a low-quality product.
When using manual labor in production, the geometry of the finished products is disrupted, which leads to the need to increase the size of the seams. This reduces the speed of laying the material, requires greater consumption of masonry mortar and causes freezing of the seams.
Wood concrete is approximately one and a half times more expensive than foam concrete or aerated concrete. This is caused by the large share of manual labor and insufficient automation of the production process.
The blocks do not have an attractive decorative appearance. Wall finishing with plaster is mandatory, hanging systems or wood paneling.

The choice of finishing materials is limited, since it is necessary to preserve the environmental friendliness of wood concrete.

Features of laying wood concrete blocks

Due to large size Wood concrete blocks are laid in 1 or 0.5 blocks. For the solution you need to prepare Portland cement, water and sand.

The first block is laid in the corner of the building, the solution is applied to the prepared foundation surface. On myself building block you don't need to put it down. The recommended thickness of the solution is no more than 2 mm. Then the level is leveled and the block is pressed tightly. Excess solution is removed with a trowel.

Subsequent blocks are laid side by side, however, the solution must also be applied to their lateral parts that are in contact. The masonry is carried out in several rows in a checkerboard pattern. The distance between the blocks is maintained the same. When applying the solution to the surface of the material, it is necessary to leave a thermal break to maintain the low thermal conductivity of the material.

There is no need to rush the construction process. Experts recommend laying no more than three rows per day, and adding special additives to the solution to increase strength and speed up the drying process. After a day, the wood concrete is securely fixed, and installation can continue.

If subsequent finishing of facades is planned using frame finishing or brick cladding, then in the process of laying arbolite blocks it is necessary to make connecting reinforcement in the walls, which can then be built into the finishing to ensure a connection between the wall and the finishing.

Arbolite is a unique material, one might say. It combines high strength and low thermal conductivity, which makes it possible to raise houses to two or three floors, taking into account the thermal characteristics of the building elements. But it has one rather serious disadvantage - high water absorption, equal to 75-85%. That is, water that gets on the wood concrete is immediately absorbed, reducing the characteristics of the building material. Therefore, plastering wood concrete from the outside is a mandatory process.

Someone solves the problem of protecting the walls of a house made of wood concrete using other technologies, for example, installing windproof facades, and makes a big mistake. Because this wall block material absorbs not only water, but also moisture. And this will lead to the appearance of mold and fungi, cracking and other unpleasant moments. No one prohibits the use of wind protection in the form of panels, siding and other materials for finishing. But it is necessary to plaster the wood concrete.

Types of plaster

What manufacturers offer today in the category of plasters for external walls. In principle, the list is not very large, so it will be easy to select the required composition.

Plaster dry mixtures based on cement.
Lime based.
Decorative compositions.
Silicone.

Cement

Until recently, cement plasters were made by hand by mixing sifted sand and cement in a 3:1 ratio with the addition of lime milk. Today, mixtures are sold dry in paper bags with precise proportions of ingredients that simply need to be diluted with water. The concentration is indicated on the packaging. Mixing is done by pouring the composition into a container of water, and not vice versa. The mixing process itself is carried out with a construction mixer.

Plastering a house made of wood concrete with cement compositions is a hardening of surfaces that will withstand heavy loads, especially impact loads. The only negative is the reduced vapor permeability. This is not to say that it is very low, but lower than that of other formulations. That is, the walls are made of wood concrete, plastered cement mortar, do not “breathe” well.

Limestone

This type of plaster is made from clean river sand and lime. The ratio can vary from 1:2 to 1:5 depending on the fat content of the lime used. Making such solutions yourself is not a problem. First, the lime is slaked, and then sand is added to it.

Manufacturers of dry plaster mixtures They offer several varieties of this material:

with the addition of gypsum to lime;
cement;
clay.

The first option is not recommended for outdoor use. But the last two are ideal in this regard. As for the last mixture, in its pure form clay and lime do not mix. Either cement or sand is still added to such a composition in small quantities.

Decorative

There is a wide variety of mixtures that differ from each other in the polymer component.

Silicate, the components of which are liquid glass. This is an elastic material with high vapor permeability.
Acrylic. Added to the composition acrylic resins. Elastic solution with low vapor permeability.
Epoxy based on epoxy resins.
Polyurethane.
Polyvinyl acetate.
Acrylic styrene.

All indicated plasters can withstand high temperatures– up to +90° and do not change their characteristics under the influence of sunlight.

Silicone

This type of facade plaster is distinguished in separate group, because this is the most expensive material of all the above, but with excellent performance characteristics. The service life of silicone plaster is at least 25 years. It is easy to apply and is sold ready-made.

Now to the question of which plaster is better for wood concrete. Basically, for this wall material it makes no difference what it will be plastered with. After all, the main task of the plaster layer is to protect the wood concrete from moisture. And all the materials described above can easily cope with this. In this case, the choice must be made according to optimal ratio prices and quality characteristics. Plus, you need to look at which wood concrete structure needs to be plastered. For example, if it is a garage or other outbuilding, then there is no point in using an expensive solution. By the way, today many people use wood concrete plaster with clay. This is the most cheap option. Not the most presentable, but it has its place.

Wood concrete plastering technology

So, the question of how to plaster wood concrete on the outside has been resolved, the composition has been selected, and we can proceed to construction and repair operations. Like all processes in construction, plastering wood concrete walls is divided into two parts: preparation and the main process.

Preparation

There is no need to carry out any complex actions at this stage. There is no need to prime the plane of the walls, because this is unnecessary for wood concrete. Blocks made from it have a porous structure due to wood chips used in concrete as a filler. Therefore, any plaster solution can be placed on them without preliminary preparation. By the way, there is no need to attach reinforcing mesh to the wall for the same reason. The only thing that needs to be done is to dust the wall with a broom.

Now two points:

If plaster is the final finishing layer (followed by a finishing coating), so to speak, leveling, then a frame made of metal profiles.
If the façade of the house is covered with a windproof structure, then there is no need to worry about the evenness of the plaster layer. special requirements. In this case, plastering the walls will simply perform protective functions.

In the second case, applying the plaster will look like this: using a trowel, the solution is applied to the surface of the wall and leveled with a trowel. The layer should be small - up to 5 cm.

IN preparatory work the first case includes the installation of metal profiles. This is done like this:

At the edges of the wall, two vertical profiles are installed, which are aligned exactly vertically and in the same plane with each other. They can be attached to the wall with plaster in the form of several piles.
Then a strong thread is stretched horizontally between the profiles in several rows (4-6).
After that, intermediate vertical profiles are installed every 100-150 cm with fastening to plaster. The installation requirement is to align the profiles exactly along the tensioned threads.

Applying plaster

Now we are plastering the house. The prepared solution is thrown with a trowel between the laid profiles and leveled long rule, pulling the material from bottom to top with moving the tool across the laid beacons. In this case, the profiles laid on the wall serve as supports for the rule.

This technology allows you to interrupt plastering. The main thing is to fill the gap between the two beacons with the mixture. If it is not possible to level all the walls in one day, the process can be postponed to the next. Nobody demands precise evenness and smoothness from the applied plaster. The task is to level big differences walls and fill the porous structure of wood concrete surfaces. By the way, this is why plastered wood concrete is a material that requires a large amount of plaster.

In this form, with the profiles inside, the walls are left for several days so that the plaster layer dries well. Then the profiles are dismantled, and their installation sites are filled with plaster or repair (cement-sand) mortar.

Note that the arbolite plaster inside is produced using exactly the same technology.

Advantages of plastering wood concrete walls

If we talk about the advantages of this method of protecting walls built from wood concrete, then three criteria should be noted.

Waterproofing wall material. Any solution described above has these qualities. And the thicker the applied layer, the higher the waterproofing characteristics. They are believed to increase depending on the application technology used protective composition. For example, shotcrete technology using a special machine.
Thermal insulation - there is no doubt here, because the thicker the external walls, the warmer it is in the house. You can increase this characteristic different ways, for example, use plaster with perlite on wood concrete or with the addition of expanded polystyrene chips.
Sound insulation - everything here is the same as with thermal insulation in terms of application thickness. But if you add crumbs to the PP solution, then this characteristic will increase several times.

Conclusion on the topic

So, several questions were considered that touched on the topics - what is the best way to plaster walls, and how to properly plaster a house made of wood concrete. From the information provided, it becomes clear that this process is no different from those associated with leveling brick, block, concrete or stone surfaces. The only difference is the absence of reinforcing mesh. The remaining requirements for the processes being carried out are the same.

Of course, we must take into account that wood concrete is a specific material. But he's easy to work with. The plaster fits well on it; there is no need to prepare the finishing surfaces. And this reduces the time for construction operations and the funds for purchasing additional materials.