Plastering wood concrete. We study the main stages of plastering walls from the inside and outside How to plaster wood concrete

Due to its positive properties, wood concrete is universal and durable material for building a house. However, when using concrete with a filler of wood chips should be considered a high degree water absorption of this component. Based on this, the facade (and sometimes internal) decoration of this material is a prerequisite. Most often, plaster is used for these purposes. To figure out how to plaster the walls of wood concrete yourself, first of all, it is worth considering the features of this finishing method.

Advantages of plastering wood concrete walls

When applying plaster on wood concrete, you can significantly improve its characteristics, since such a coating performs the following functions:

• Heat shield. The house retains heat without the effect of "steam room". Due to good vapor permeability, the plaster allows the wood concrete to "breathe".
• Soundproof. If the plaster is not painted, it will reliably protect you from unwanted noise.
• Waterproofing. Plastered wood concrete repels water, so rooms with high humidity(but not more than 70%) do not require additional finishing. To enhance the water-repellent properties when applying plaster, it is recommended to use a shotcrete machine.

Plastering is also necessary if aggressive acid fumes are exposed to the walls of the building.

Another plus of plaster is its composition, which forms a rough surface that allows you to achieve high level adhesion of plaster material with wood concrete surface. In this case, you do not have to additionally process the walls and prepare them for finishing.

In addition, the plastered facade of the building should be updated no more than once every 8-9 years. To do this, it is enough to "walk" along the walls with a primer, spending a minimum of money on this.

If we talk about what exactly can be used to plaster walls from wood concrete, then it is worth highlighting several types of this finishing material.

Plaster compositions for wood concrete walls

For self-finishing surfaces from wood concrete, it is recommended to use the following types of plasters:

• Cement. A mixture of sifted sand and cement is suitable for standard walls with a thickness of about 30 cm. The plaster is applied 2 cm thick.
• Plaster. Gypsum and various fillers are used as a finishing material.
• Lime. The main component is lime. In this case, after covering the surface with plaster, it is puttied over the primer and painted with facade paint.
• Compositions for decorative finishes. Such plasters are different types: lime, acrylic, latex and others. Acrylic composition is considered the most convenient to use. Also decorative mixtures have high vapor permeability.

Some specialists add lime paste (about 0.5-1 parts) or water-retaining additives to ordinary cement mortar.

However, it should be borne in mind that when adding some additives (polystyrene foam, foam glass or slag), the walls will “breathe” worse. This is due to the different vapor permeability of materials, resulting in the formation of a dew point (the walls freeze through and become covered with wet spots inside). If you do not want to disturb the air permeability of wood concrete, then it is recommended to use expanded clay, barite, perlite or vermiculite as additives.

The process of applying plaster on an arbolite surface differs from the processing of other concretes in its simplicity. Apply protective layer it is possible almost immediately after construction, it is not necessary to process the surface or use reinforcing meshes.

Healthy! The use of a reinforcing mesh in the plastering process will increase the service life of the finish, but even without it, the plaster composition will firmly “stick” to the surface.

Nevertheless, before you quickly plaster the walls of wood concrete yourself, we recommend that you familiarize yourself with some of the features of the external and internal decoration with various materials.

Features of internal and external finishing of arbolite walls

If you plan to use plaster as a cladding, then you need to consider that this construction material should not be used for interior decoration of premises with aggressive conditions.

Mixtures for plaster, which include perlite, are good heaters, so after processing the surface can be pasted over with wallpaper.

Also, lining is used for interior decoration, however, such a lining has its drawbacks:

• high cost;
• high fire hazard;
• during installation, it is necessary to prepare a wooden crate.

For interior decoration, drywall is used, with which you can make any shape and create a unique design of the room. However, it also requires the preparation of a frame.

If we talk about how to cover the walls of the house with outside, then the cheapest and affordable option will be all the same plaster. Some prefer brick because of its heat and sound insulation characteristics, but in addition to its high cost, it requires constant maintenance. Although when installing a brick it is not necessary to prepare a layer of insulation, between the wood concrete and brickwork be sure to leave a gap of 40-50 mm to avoid moisture. In addition, for brick cladding you need to install a good ventilation system, otherwise the wood concrete blocks will quickly collapse.

If you plan to do the work yourself, while spending a minimum of effort and Money, then it is better to give preference to ordinary plaster.

Plastering wood concrete blocks is considered the simplest and most reliable way to finish them in order to decorate and protect them from moisture. Optimum performance for application have moisture-resistant, but breathable mixtures, distributed in a thin layer within 20 mm. It is recommended to process walls on both sides, the difference is manifested only in the solutions used and the technology of their installation. The result achieved largely depends on the quality of the products and the evenness of the masonry; in order to avoid mistakes, it is worth studying all the requirements in advance.

The choice of compositions for plastering

The need for mandatory protection is easily explained; with all its advantages, this composite building material has a high degree of water absorption (40-85%) and is not intended for use in open form. At the same time, it is not advisable to close it with an impermeable lining due to a decrease in the ability to air exchange and the inability to remove accidentally accumulated condensate from them. This rule applies both when processing walls outside, and when working indoors. The application of moisture-resistant, but porous and breathable mixtures solves this problem completely, the resulting coating combines protective, leveling and decorative functions.

1. Cement-sand mortar, applied with a layer of up to 2 cm. This variety is selected mainly for rough finishing, including when planning to close the outside with a system of ventilation facades. It is valued for its low cost, resistance to moisture and most external influences, but inferior to other types in permeability, maximum effect achieved when protecting rooms with high humidity, unheated and outbuildings: garages, workshops, baths.
2. Lime plaster, characterized by increased vapor permeability and plasticity and mainly used for rough finishing wood concrete walls indoors. V facade works it is used in combination with water-repellent paints.
3. Gypsum mixtures ideal for interior cladding.
4. Decorative compositions based on acrylic or silicone resins, water glass or complex binders. These species have different characteristics, to general properties include good hiding power, wear resistance and the ability to change color by introducing pigments. Silicate or silicone grades have best performance UV resistance, permeability and water repellency, they are practically not subject to pollution and do not need to be updated for a long time.

The plaster layer is used as a draft, leveling, heat, sound or waterproofing and acid-resistant, in some cases their functions are combined. Each of the listed varieties has its pros and cons; it is impossible to call any of them universal in relation to wood concrete. Wide use received cement-based grades with minor additions of gypsum or lime, which positively affect the vapor permeability index, or water-retaining impurities.

In order to avoid errors, it is recommended to use specialized dry mixes; when preparing it yourself, it is important to monitor the degree of permeability of the introduced components. special attention require thermal insulation types, foam glass, crushed slag or foam plastic chips cannot be introduced during their mixing, the optimal combination is achieved by combining a cement or complex binder with crushed expanded clay, perlite, vermiculite or a similar breathable filler. There is no need to introduce antiseptic or anti-corrosion additives, wood concrete has a biostability group V and does not need additional protection from any external influences other than moisture.

Features to be considered include High Quality adhesion, the applied layer does not need to be reinforced with a mesh or pre-treated with soil. This is due to the same permeability and elongated shape of the chips, the solution penetrates into upper layer and securely held between the individual fibers. But this property has negative side – high flow materials and the risk of cracking due to the rapid absorption of moisture from the plaster.

On average, 34 kg of DSP, 30 of lime mixture, 9 of gypsum-based finishing and 8 of decorative types are spent on facing 1 m2.

When performing a rough finish of arbolite blocks, the thickness of the applied layer is maintained within 20 mm, finishing - 7-10. Expensive silicone, acrylic and silicate varieties are spread over the plane with a brush, trowel or wide spatula. The thickness of their layer after drying does not exceed 1-3 mm, but for obvious reasons they are not applied directly to the surface and need a rough base. At the same time, it is recommended to treat the walls outside the house with brands with high UV resistance; acrylic ones are inferior to silicate ones in this regard.

The nuances of the work

The sequence of actions depends on the novelty of the structures: plastering of newly erected systems is started immediately (treatment with soil is required only if there is doubt as to the quality of wood concrete), previously operated - after the removal of old building materials and thorough cleaning of weak particles. Masonry from factory blocks or slabs, as well as a wall filled with monolithic technology, does not need to harden auxiliary beacons, they can be processed without pre-training. An exception is made only when building in hot weather - the surface is gently moistened.

Do-it-yourself plaster on wood concrete

Wood concrete, a “specific” building material that strongly absorbs moisture and can gradually collapse under its influence. However, this fact does not mean that wood concrete walls cannot be plastered with wet mortars.

You should also know that having built its walls, at least from the outside, it is recommended to immediately insulate and decorate with finishing material. Only in this case, their surface will be reliably protected from the negative effects of moisture, and, accordingly, will last much longer.

When wondering how to plaster wood concrete, it is important to know that almost any modern Decoration Materials. It can be used for plastering walls from wood concrete blocks and ordinary cement plaster. However, due to the fact that wood concrete absorbs water very strongly, the process of plastering walls itself becomes a little more complicated.

Firstly, it is recommended to apply plaster on wood concrete walls with a thickness of at least 2 centimeters. In the very composition of the cement-sand mixture, it is recommended to add water-retaining additives or, in extreme cases, 0.5-1 part of milk of lime.

The very same plaster on wood concrete is not much different from plastering walls made of brick, for example, or cinder block. In a sense, it is even simplified due to the presence of a rough surface of wood concrete, with large quantity cracks - the solution sticks to it much better.

Some difficulties may arise with the thickness of the plaster on wood concrete, since those people who have encountered this building material for walls know that it does not always differ in its evenness. geometric shapes. And if the differences in the surface of the walls are significant, then sometimes you have to throw in two or three layers of plaster in order to finally level them.

In this case, unfortunately, one cannot do without the use of guide beacons. Before putting them up, you should carefully mark the surface to be plastered, find the most protruding places on it, etc.

How it is done has already been described in previous issues. As for the plastering of wood concrete blocks, the situation here is similar. The only difference is in the number of layers thrown, and in their thickness.

The first plaster layer should not be made too large, but before throwing on the second layer, you need to wait a while. Fortunately, wood concrete, as mentioned above, absorbs moisture very strongly, as you can see for yourself by watching a video about wood concrete blocks.

Video about wood concrete blocks

Arbolite is a material, one might say, unique. 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 he has one rather serious minus - high water absorption, equal to 75-85%. That is, the water that has fallen on the wood concrete is immediately absorbed, reducing the characteristics of the building material. Therefore, plastering wood concrete outside is a mandatory process.

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

Types of plaster

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

1. Plaster dry mixes based on cement.
2. Based on lime.
3. Decorative compositions.
4. Silicone.

Cement

Until recently, cement plasters were made by hand by mixing sifted sand and cement in proportions of 3: 1 with the addition of lime milk. Today, the mixtures are sold dry in paper bags with the exact proportions of the ingredients, which simply need to be diluted with water. The concentration is indicated on the package. 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 from wood concrete cement compositions- this is the hardening of surfaces that can withstand heavy loads, especially shock. The only negative is the reduced rate of vapor permeability. It cannot be said that it is very low, but lower than that of other compositions. That is, walls made of wood concrete, plastered cement mortar, badly "breathe".

Lime

This type of plaster is made from pure river sand and lime. The ratio can vary from 1:2 to 1:5, depending on the fat content of the lime used. To prepare such solutions with your own hands is not a problem. First, the lime is quenched, and then sand is added to it.

Producers of dry plaster mixtures offer several varieties of this material:

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

The first option for outdoor use is not recommended. But the last two are perfect in this regard. As for the last mixture, in its pure form, clay and lime do not mix. In such a composition, either cement or sand is added in a small amount anyway.

Decorative

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

1. Silicate, the components of which are liquid glass. It is an elastic material with a high vapor permeability.
2. Acrylic. Acrylic resins are added to the composition. Elastic mortar with low vapor permeability.
3. Epoxy based epoxy resins.
4. Polyurethane.
5. Polyvinyl acetate.
6. Acrylic-styrene.

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

Silicone

This type of facade plastering is separated into a separate group, because it is the most expensive material of all of the above, but with excellent operational characteristics. The service life of silicone plaster is at least 25 years. It is easy to apply, it is sold ready-made.

Now to the question, which plaster is better for wood concrete. Basically, for this wall material there is 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 should be made according to the optimal ratio of price and quality characteristics. Plus, you need to look at what kind of wood concrete structure you need to plaster. For example, if it is a garage or other outbuilding, then it makes no sense to use an expensive solution. By the way, today many people use clay arbolite plaster. 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 from the outside has been resolved, the composition has been selected, you can proceed to construction and repair operations. Like all processes in construction, arbolite wall plastering is divided into two parts: preparation and the main process.

Training

There are no complicated steps to take at this stage. It is not necessary to prime the plane of the walls, because it is unnecessary for wood concrete. Blocks from it have a porous structure due to wood chips used in concrete as a filler. Therefore, any plaster solution to lay down on them without prior preparation. By the way, there is no need to attach a 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:

1. If the plaster is the final layer of finish (followed top coat), so to speak, leveling, then a frame of metal profiles is assembled under it.
2. If the facade of the house will be closed with a windproof structure, then there are no special requirements for the evenness of the plaster layer. In this case, the plastering of the walls will simply perform protective functions.

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

V preparatory work in the first case, the installation of metal profiles is included. It is done like this:

1. Two vertical profiles are installed along the edges of the wall, which are set exactly vertically and in the same plane between them. They can be fixed to the wall with plaster in the form of several piles.
2. Then a strong thread is stretched horizontally between the profiles in several rows (4-6).
3. After that, intermediate vertical profiles every 100-150 cm with fasteners on plaster. The requirement for installation is to set the profiles exactly along the stretched threads.

Applying plaster

Now we are plastering the house. The prepared solution is thrown with a trowel between the laid profiles and leveled with a long rule, pulling the material from the bottom up with the tool moving across the laid beacons. At the same time, the profiles laid on the wall act as supports for the rule.

This technology allows you to interrupt the 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 transferred to the next. No one requires exact evenness and smoothness from the applied plaster. The task is to even out large differences in the walls and fill the porous structure of the wood concrete surfaces. By the way, that is why plastered wood concrete is a material that requires a large amount of plaster.

In this form, with profiles inside the walls, they 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 plastering of wood concrete inside is carried out according to exactly the same technology.

Advantages of plastering walls from wood concrete

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

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

Conclusion on the topic

So, several questions were considered that touch on topics - the better to plaster the walls, and how to properly plaster a house from 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 a reinforcing mesh. The remaining requirements for ongoing processes are the same.

Of course, it must be borne in mind that wood concrete is a specific material. But he is easy to work with. The plaster fits well on it, it is not necessary to prepare the finishing planes. And this reduces the time of construction operations and funds for the purchase of additional materials.

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

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

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

The most popular wood concrete finish is plaster. Perlite plaster is now very popular, which not only protects against blowing and improves appearance, but also gives significant insulation to the walls.

If you choose to do masonry mortar and plaster with perlite on its own, 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, then gives it back, which creates additional difficulties when preparing a solution with dry perlite.

FINISHING PRODUCTS FROM ARBOLITA

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 finish. Field surveys of buildings for various purposes, carried out in various climatic zones of our country, showed that in structures with a good protective and finishing coating, arbolite has a stable humidity not exceeding 12%, and the buildings are in good condition. And vice versa, with low-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 moisture content of wood concrete in such structures, regardless of the orientation of the walls and climatic zones, is usually high (more than 30%). With such humidity, the strength characteristics of arbolite sharply decrease, its deformability increases, 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 surface moistening, structures made of 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.

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

At several enterprises of the Ministry of Forestry of the USSR, bilateral invoices are carried out. Most often, buildings erected from wood concrete structures are finished on construction site. In this case, the walls of arbolite structures are plastered cement-sand mortar, then on the outside, whitewash with the addition of pigments is used (less often, paintwork is used), and on the inside, depending on the purpose of the building, wallpaper is glued 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 research, such protective coatings were chosen, which have proven themselves well in the process of operation with cellular concrete. These are paints TsPHV, KCh-26, VA-27A, latex-organosilicon whitewash, lime-organosilicon whitewash, etc.

The quality of the finish was evaluated by the frost resistance of the protective and finishing coatings and the arbolite protected by them, by their resistance to alternating wetting and drying, by reducing the adhesion strength of the textured layer and arbolite from these influences. As a result of the research, the following has been established:

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

paints KCh-26 and VA-27 A, not intended for exterior coatings, but showing sufficient resistance to frost, can be recommended for finishing and protecting the internal surface of enclosing structures of unheated buildings with a wet operating mode;

The latex-organosilicon whitewash recommended by the "Guidelines for the design and manufacture of wood concrete products" can also be used for protective and finishing coating of wood concrete structures. However, it should be noted that during its preparation and application, difficulties arise associated with the ongoing reaction between the components of the protein and its separation. At the same time, it was noted in the studies that small cracks formed on the coating with VA-27A paint after 45 cycles. The formation of cracks on the coating with KCh-26 paint began already after 35 cycles, and the latex-organosilicon paint began to flake off in places from the textured layer after 40 cycles.

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

The results of studies of the frost resistance of textured layers with various chemical additives and protective and 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 a positive effect both on reducing water absorption through the textured layer and on the adhesion of the textured layer with wood concrete; the best results were obtained with the introduction of 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 with wood concrete was observed after testing the samples for frost resistance, which is probably due to the good waterproofing properties of these coatings, which cause 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 with wood concrete decreases when moistened and dried, as does the strength of wood concrete, but more intensively. This is apparently due to the different magnitude of moisture deformations of the textured layer and wood concrete and the concentration of stresses in the boundary zone;

all protective and finishing coatings applied on the textured layer increase frost resistance and resistance to alternating wetting and drying of the textured layer compared to uncoated control samples in proportion to their decrease in water absorption through the textured layer.

The most effective coatings were found to be latex-organosilicon whitewash and TsPCV paint, less effective coatings were calcium stearate and lime-organosilicon paint. good protection from moisture provides treatment of the textured layer with water repellents and polymeric materials(GKZH-10, PVA, SKS-65GP latex).

Studies have shown that coating the surfaces of wood concrete structures significantly increases the durability of this material, gives the products and buildings built from them a beautiful appearance. However, these types of finishes have not yet found wide application in the production of wood concrete, as they are scarce and quite expensive. Considering all these factors, we proposed protection and finishing of wood concrete with concrete layers with simultaneous installation decorative coating from ceramic breccia.

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