How to plaster concrete walls. How to plaster concrete walls with your own hands in an apartment: the better to plaster, is it necessary with gypsum and how to properly align using the technology Do-it-yourself plastering of concrete walls with cement mortar
During construction own house or repair work often you have to face the need to level the walls and their subsequent finishing. It should be remembered that the plaster concrete walls DIY is a rather laborious and long process that requires at least minimal skills.
This is the most important stage of finishing work, regardless of whether you will paste over the room with wallpaper, or prepare the surface for subsequent painting. Some finishers recommend removing all the flaws of the concrete wall by sewing up the room with drywall, but it is worth considering the fact that such walls are simply not able to withstand heavy loads. Subsequently, it is impossible to hang on a plasterboard wall plasma tv, air conditioner, boiler and others Appliances who have firmly entered the life modern man. Therefore, the most acceptable finishing option should be chosen plaster.
Plaster classification
It should be borne in mind that today many types of plasters are used for finishing work, designed to perform various functions. The most common are:
- ordinary (gypsum or cement-sand) plasters, which are great for leveling the surface of walls, and are also designed to protect walls from dampness, moisture and other environmental influences;
- special-purpose plasters are mixtures with narrowly targeted characteristics that are used for sound insulation, protecting the room from various kinds of radiation, heat-saving plasters, etc.;
- decorative plasters, as the name implies, are intended for finishing finishing works and give the surface an aesthetic appearance.
Before starting work on plastering the surface, it is necessary to carry out preliminary work to remove dirt, dust and residual organic liquids from the wall in order to provide a strong bond between the concrete surface and the plaster layer. Then a solution is made from the dry mixture. The method of preparing the solution and the proportions of the necessary components are indicated on the package, therefore, on this stage there shouldn't be any difficulties.
The peculiarity of plastering concrete walls is that their surface is usually smooth and even. Because of this, the layer of plaster may fall off. However, do not despair. Serifs are applied to the walls, with the help of which the layer of plaster adheres perfectly to the base.
After the serifs are made, an indispensable step in plastering the wall will be applying a special primer. Its purpose is twofold. In the first case, the primer allows the plaster to adhere tightly to the wall surface, absorbing excess moisture, and in the second case, it provides various kinds of wall protection from external influences. There are antiseptic soils, antifungal and many others.
When the soil dries, you can proceed directly to the process of plastering the walls. Initially, the mixture is applied by the so-called "splashing" method from a special pump. In the absence of technical equipment, plaster can be applied manually with a special spatula. In this case, the plaster literally pounces on the surface of the wall, filling all the small cracks and pores.
The next step in the plastering of concrete walls is the application of a second layer of the mixture. In this case, the surface will look smoother, since the second layer is applied from a thicker mixture. At this stage, the process completely repeats the previous steps, with the only difference being that it takes a little more time to dry. And, finally, the final layer of plaster is applied with the same liquid mortar as the first: this provides an opportunity to correct all the irregularities and flaws made in the previous stages of work. After drying this layer, the wall in the room looks amazingly white and even.
Features of plastering concrete walls
It should be remembered that the concrete surface requires particularly careful work on the plaster.
Each layer must be literally "rubbed" into the surface, so that later it firmly adheres to it.
The thickness of the main (second) layer usually does not exceed 5 mm, but this is the case when the walls are relatively even. It should be borne in mind that when leveling the walls it may turn out that the plaster layer will be inhomogeneous in thickness, so take this into account when drying the surface.
Video
We bring to your attention a video in which a story is told about the plastering of concrete walls.
That is, the installed frame and formwork are poured with a concrete solution. This significantly reduces costs and construction time. A concrete wall is quite practical and durable, but it has one significant drawback: the walls turn out to be crooked. That is why the walls are leveled with high-quality plaster.
In this case, plaster is necessary not only for leveling, but also to cover the seams and prevent moisture from entering the wall. But not everyone knows how to plaster a concrete wall.
Available plaster options
Interior walls of houses. For example, using dry plaster sheets, wet method or processing synthetic materials manufactured at factories, as well as ready-made mixtures.
Laying dry sheets is quite simple, but a wet mortar is considered one of the most laborious, although the quality of such plaster is considered ideal. Synthetics are more plastic and easy to install, but there are certain nuances that you will learn about later.
General Benefits
The main advantages of plaster:
In addition to the above, in contrast, plaster is able to withstand large mechanical loads and temperature changes.
Preparatory work
Surely this is not the first time you hear about the need proper preparation surfaces before plastering the concrete wall. And this is not in vain, because evenness, quality, durability and strength of the overlap depend on it. Of course, you should thoroughly clean the wall from dirt, dust and other things, as well as provide it with roughness.
Cleaning of new buildings and previously finished walls
In the event that you will clean the walls of a newly built building, you need to remove all remnants of formwork lubricant, and all kinds of sags, protruding fragments and the like must be cut down. It is also important to get rid of any greasy spots, dust and resin. This can be done either with the help of an improvised tool (broom, brush, rag or scraper), or by blowing with compressed air. Alternatively, copious rinsing with a stream of water may be suitable.
Walls that have remnants of the old coating (paint, wallpaper, and so on) must be thoroughly cleaned. If there are loose layers of putty, get rid of them. Cover cracks, potholes, etc. with a thick layer and sand with sandpaper.
Notches must be applied to concrete surfaces so that the adhesion to the plaster is stronger. This can be done with a hammer, hatchet, chisel and. Use plastic plugs or styrofoam to protect electrical installations. And in order not to contaminate the system pipes, cover them with foil beforehand. Next, check the stability of the surface base by tapping on the wall. If the sound turns out to be muffled, everything is fine, otherwise you need to knock down the fragile layer and make a new one.
Primer
The primer itself increases the strength and durability of the wall, improving the quality of adhesion. Also noteworthy are corrosion, decay and other adverse factors. The primer perfectly accelerates the drying process, develops resistance to moisture and, for denser surfaces, improves the absorption of solutions.
IN modern world manufactured unique look primers - concrete-contact, which perfectly stabilizes the surface and increases the quality of plaster application. This is a durable material, but before applying it, you need to carefully clean the wall.
Net
At the joints of concrete with other materials used, as a rule, heterogeneous in structure, plaster usually cracks. This happens due to the fact that the coefficient of thermal expansion is completely different, “due to” which drying on them is uneven.
In order for you to avoid such problems, we will tell you how to plaster a concrete wall correctly. To do this, you will need a special fiberglass mesh (size 5 × 5 mm), which must be applied to the middle of the joint and the edges fixed.
It also happens that the layer thickness is more than 20 mm, then it is necessary to level the walls along the plaster mesh tightly. The section may be different. By the way, such a mesh further provides strong protection against cracking during impacts, elevated temperatures and humidity. In order for the plaster mesh to meet all the requirements, the stretch must be maximum, and if the mesh is metal, it should be painted to prevent corrosion.
Last preparation
The last thing you need to do is properly check for evenness. With the help of a level, plumb and laser level it is necessary to hang the surface to determine the accuracy of the horizontal and vertical plane. Having installed beacons and marks, they are leveled.
Inspect the surface again for dust, dirt, stains, and protrusions. Because in the process of preparation, unnecessary trifles may arise. Then you can start plastering.
Plastering process
The process of this work includes not only applying the solution to the surface, but also preparing the mixture.
Solution
You can prepare the appropriate mortar for plastering a concrete wall. Basically, lime or sand-cement mortar is used for these purposes. You can make it yourself or buy a ready-made dry mix in a specialized store. The mixture is easier to prepare, since it just needs to be mixed with a certain amount of water indicated on a specific package.
Unfortunately, the price of such a mixture is high, so it is not available to everyone. A self-made solution is much cheaper. Cement-lime mortar is made from cement, lime mortar and river sand in the ratio 1:2:7. First you need to dilute lime with water to a doughy state, mix sand and cement separately and add this to the lime solution. If the mixture is too thin or, conversely, thick, you can dilute it with sand or water.
Cement mortar consists of one part of cement and two parts of sand. Due to the fact that sand reduces the plasticity of the mixture, it is not recommended to add more than three parts of it. In the prepared container, it is necessary to alternately pour the constituent ingredients, then mix and fill with water. This mortar hardens quickly, so do not prepare it ahead of time.
Some people also use lime-clay composition in order to plaster concrete surface. First, dilute clay with water and lime with liquid separately to the consistency of dough, then combine the clay mixture (1 part) with lime (0.4 parts) and sand (3-4 parts).
Also from lime, clay and gypsum. First, make a lime-clay mortar, and dilute gypsum with water in another container. Mix these mixtures in proportions of 1:3. But for a concrete surface, it is better not to use an admixture of clay.
Tools
Before you get started, get the tools you'll need. For this you need: steel brushes different sizes, all kinds of scrapers, cogwheel, falcon, flywheel, plumb line, grater, plastering trowels, special ladle, semi-terre, cogwheel. As well as the level and rule, screws and wooden slats, trowel and wedge at 1.5 m.
Of course, dry mix or components of the solution. If you prefer ready mixes, then it should be taken into account that their composition may include synthetic substances and plasticizers that have the ability to slow down or accelerate the hardening process. Focus on this.
First step
After the preparatory work you need to outline the places for the installation of prepared wooden slats. The height of all boards must be equal to the height of the wall, and the thickness cannot exceed 10 mm. With these slats, you need to divide the area into certain sections up to about a meter. you can use screws designed for stone, then check the vertical evenness with a level. All this must be done in order to make it easier for you to remove the rails later.
Without fail, moisten the surface with water and immediately plaster the walls. Start from the corner of the room. When the time comes to level the solution, use force, but keep in mind that this must be done within the two beacons, the role of which is played by the slats. After complete hardening, carefully remove the boards, and cover the resulting grooves.
The first layer when applying plaster
Since it is necessary to plaster a concrete wall strictly in three layers, we suggest that you familiarize yourself with each one separately. The very first layer is called "splash", the solution of which has a creamy consistency. This is the most liquid layer. Considering that the concrete is puttied, the thickness of the “spray” should be a maximum of 5 mm.
With a trowel, it is necessary to draw part of the solution into the falcon, then from it, using a spatula, random order throw on the wall. You need to know that this movement is made only with the hand, and not with a full swing. This is done so that all the voids that exist in the wall must be filled.
In principle, it is possible to apply a plaster solution and spread it, but almost no one uses this method. Try to rinse the tool after each next section that you have plastered.
Second layer
After the final drying of the first layer, knead the soil solution, which should have a pasty structure. When laying a layer of "soil", use the same method of scribing. After filling the entire area, level the surface of the wall with the rule and remove the excess.
Pay attention to emerging voids that should be filled with a mixture. After all this, level the wall with a tool such as a trowel in two main directions: horizontally and vertically. Do not forget all the time to control the evenness of the wall with a level. Layer thickness - up to 10 mm.
third layer
This layer is the final one, which is why it is called “covering”, the consistency of this solution should correspond to the previous one, and the application thickness should not exceed 2 mm. This layer is considered a finishing layer, so it must be done very carefully, without any errors. It should hide all the flaws of the ground.
Before mixing the solution, be sure to sift the ingredients and mix thoroughly so that there are no lumps or large particles. Next, you need to moisten the second layer of plaster and use a trowel to apply a small layer of mortar, then smooth it with a trowel, doing it in a circular motion or in waves.
Video on how to plaster concrete walls:
Lighthouse plastering
In addition to the main method described above, you can do plastering using various types of beacons. This is necessary when the walls are very uneven and convex. Basically, in order to perfectly level the wall, strict control of the horizontal and vertical lines is carried out. This is a very complex process that is best left to an experienced professional.
To make it clearer to you, we will briefly look at how to plaster a concrete wall using beacons. For this type of work, you need to make markings at the top and bottom at the same level and screw self-tapping screws into them, hang a weight that will play the role of a plumb line. Apply a small amount of mortar between two nails. In the same way, you need to hang beacons around the entire perimeter of the room. The beacon is installed on the heaps of the applied solution and pressed into it. This must be done so that the beacons rest against the screws.
Video on how to plaster on lighthouses:
Then you check the evenness of the surface by the beacons, relative to each other and in the plane. After that, they are smeared with a solution and dry. Next, plaster layers are applied according to the generally accepted method.
Grout
After the concrete wall has been plastered with the last layer, immediately proceed to grouting without waiting for drying. Grouting must be done in two stages. First, around, that is, you need to press the canvas of a wooden ironing board to the surface and make circular movements strictly counterclockwise. In this case, the sharp edge of the canvas will cut off all the protrusions, bumps and unnecessary plaster.
The next stage involves grouting in acceleration. To do this, press the grater against the wall and make straight strokes with sharp movements. In this way, traces of grout, made round, are removed. And in order to improve the grout, put on a grater soft tissue(such as felt or felt) and rub the surface.
Finally
In principle, you have already understood how to plaster a concrete wall, so it remains only to supplement and summarize. In order to do it qualitatively and get an impeccable result, do not spare money and buy all the necessary equipment, because it facilitates work and helps in work.
Remember that each layer of the solution is applied only after the previous one has completely dried. A lime-based mortar is considered to be dry when the wall turns white, on cement - within 2-6 hours, on lime-gypsum - within 10-15 minutes. Don't experiment with different solutions- it is unacceptable. Use the same solution for each layer. And do not forget the main condition for high-quality plaster: both the last and every other layer must be done neatly, evenly and cleanly. The quality of further decorative finishes depends on this.
Both in the new house and during the overhaul owners are sure to face the problem of plastering walls. Since plastering works are quite different high cost, then many are interested in the question of how difficult it is to plaster the walls on their own.
The process of plastering, of course, cannot be called a simple event. When carrying out work, a lot of dirt and dust is always generated, in addition, work operations require patience and care. But, with a little experience and certain knowledge, you can plaster the walls with your own hands.
Plastering concrete walls will allow you to qualitatively level their surface in order to further finish it in accordance with your own taste and, without striving to choose a material that will mask the flaws.
For leveling concrete walls, in most cases, a mortar prepared from a lime-gypsum mixture is used. For its preparation, lime and gypsum should be used in a ratio of 1:3 (4). The method of preparation is as follows: gypsum is mixed with water in a special container, after which lime is added to it. The solution should be of medium consistency.
A sand-cement mortar can also be used, it is prepared in a ratio of 1: 3 (cement: sand). When using special dry plaster mixtures, the manufacturer's instructions are binding.
Important! Any solution should be prepared in small quantities and used within half an hour.
Stages of plastering concrete walls
Before proceeding to plastering work the surface of the walls must be cleaned of dust pollution. Care should be taken to remove any existing greasy or other stains from the wall surface. If this is not done, they may appear on the plastered surface and later on the finishing coating.
Concrete walls are characterized by increased smoothness, so it is necessary to make notches on them before plastering, which will improve the adhesion of the wall to the mortar. To do this, use a hammer and gear. On one square meter surfaces should be made approximately 250 pieces.
The dimensions of the notches performed:
- Length 1.5cm;
- Depth 3 mm.
Also, to roughen concrete walls, you can use sandblasting machine. If differences up to 2 mm are observed on concrete walls.
After applying the notches, the surface should be primed special composition. It absorbs excess moisture from concrete surfaces and guarantees good adhesion of the mortar to the wall. Soil formulations with antiseptic, antifungal properties should be used. Plastering of wall surfaces begins after the primer layer has dried.
The process of leveling walls with plaster involves the application of several layers. Be sure to moisten the wall surface before handling the solution.
The first layer is spray applied. Its main purpose is to qualitatively fill all the existing cracks and sinks in the surface. A relatively liquid solution should be used at this stage. It should be remembered that the layer thickness should not exceed 5 mm.
Throwing the mortar onto the wall surface is carried out with the help of a trowel with sharp movements. At first, difficulties may arise, since it is required to choose the sharpness and strength of the throw. In this regard, it will take some time to adapt. If it fails to perform a spray. You can spread the solution on the wall with a special spatula, but this method is less preferable, since it does not provide sufficient adhesion of the solution to the wall surface. The layer obtained by "splashing" is not leveled, only strongly protruding areas are removed.
After the first layer has completely dried, the next layer is applied, which is the main one. For it, a thicker solution is used. First, the mortar is also thrown onto the wall, while it is necessary to fill all the possible recesses left after the spray as much as possible, then it is leveled using the rule. Optimal Thickness the second layer - 5 mm.
Alignment of the main plaster layer is carried out with the help of a semi-trailer, which must be carried out along the wall surface in the horizontal and vertical direction. During the leveling process, the thickness of the plaster layer is periodically controlled using a rule.
After the base layer dries, a final layer is formed, which is called the “cover”. For this, a solution of medium consistency is prepared. The purpose of this layer is to completely hide the slightest defects on the plastered surface. Therefore, when preparing the solution, the sand is sifted through a sieve to eliminate lumps that will not allow creating an ideal surface. The layer thickness should not exceed 2 mm.
The process involves applying a thin layer of mortar to a pre-wetted surface using a special plaster spatula. After that, the process of leveling with a semi-terre in circular motions begins.
Without waiting for the third layer to dry, a fine grout is made with a grater. This is first done in a circle, and then overclocking.
In this case, the grater is pressed tightly against the wall surface, and circular movements are performed. Thus, cutting by its edge is performed various irregularities and smoothing the plastered surface. After that, pressing the grater tightly against the wall, you need to perform direct movements that remove traces of circular grout.
Important! Plaster layers should dry naturally. Do not use additional heating, this will lead to cracking of the plastered surface.
Wall plastering is the basic stage of repair and construction work, both in a new building and in a residential area. Masterfully executed surface plastering will allow you to make any fine finish, without significant structural changes. Despite its apparent simplicity, the plastering process is a complex and responsible undertaking, the implementation of which requires certain knowledge and skills.
Features of plastering concrete walls
Concrete is quite common construction material, found in old buildings and used in the construction of modern structures. Concrete walls are good operational characteristics, but the technology of their finishing is more complicated due to the high density and hardness of the material.
An important stage of many repair and construction works is wall plastering. Preparatory process cannot be bypassed, like painting the surface, laying tiles or wallpapering. Some masters try to simplify the task and "sheath" concrete base drywall. However, such a wall is not able to withstand heavy loads - it will not be possible to hang a TV, a boiler and more on the GKL household equipment. Therefore, plastering is still considered the best way to finish.
Finishing a concrete wall in comparison with plastering a brick surface has a number of features:
- Ceramic bricks have many pores that, like a sponge, absorb the solution. Thanks to this structure, the plaster adheres tightly to the base of the wall.
- On the concrete surface, due to its smoothness and density, the plaster composition is poorly retained.
- Fulfilling Finishing work, it must be borne in mind that plaster dries longer on a concrete wall than on a brick. In addition, it is important to take into account that when leveling the wall, a layer of plaster is applied with a layer that is not uniform in thickness, and this affects the drying time.
- Before applying the plaster mass, the concrete base needs special preparation - applying serifs, using a primer, attaching a reinforcing mesh, etc.
Important! When plastering a smooth concrete wall, each layer must be literally “rubbed” into the base so that it does not subsequently fall off and spoil the new finish.
The choice of mixture for plastering concrete walls
The leveling of the concrete surface inside the building is carried out using cement-lime compounds or polymer-cement mortars with the addition of plasticizers. All plaster mixtures for concrete finishing can be divided into three categories:
- Ordinary mortars based on sand, gypsum or cement. The materials are suitable for leveling surfaces and provide the base with protection from excessive moisture. A significant plus is the affordable price.
- Compounds for special purposes, for example, to increase sound insulation or thermal insulation, antifungal, etc. Mixtures have been developed, the use of which reduces the impact of harmful radiation.
- Decorative plaster for wall finishing. With the help of such compositions, it is possible to create an imitation different surfaces. Textured decorative bulges and hollows give unusual effects and change the visual perception of space. Lack of material - high cost.
The mortar for plaster can be prepared independently or bought already ready composition. When mixing, observe the right proportions which will ensure the strength and durability of the plaster. In purchased mixtures, all components are already dosed.
All plaster compositions have two components: filler and binder. Used as a filler different types sand. Depending on the type of binder, mixtures are classified into the following types:
- calcareous;
- cement;
- plaster;
- cement-lime;
- adhesive solutions.
Plaster mixes are selected depending on the place of use (treatment of internal or external surfaces) and the base material. Each composition has both advantages and disadvantages.
cement mixtures- universal, they are used when carrying out repairs inside the house or finishing the facade. The main advantages of the solution are high strength and affordable price. Additional benefits include:
- practicality - unused bags of dry mix will come in handy when performing subsequent repair and construction work;
- mixed solution can be used long time, without fear that the mixture will harden - this property allows you to immediately prepare a large amount of the mixture with a concrete mixer.
When working with cement plasters, it is necessary to take into account some of the disadvantages of the solution:
- low adhesion with concrete surfaces - this drawback, as a rule, manifests itself with excess sand;
- coat cement plaster physically difficult;
- inability to use the solution in a room with wooden structures- the technology of applying the cement composition requires its periodic moistening during the drying period. At the same time, the humidity in the room rises, and wood elements can be deformed;
- plastering with cement is a very dirty and dusty job;
- long hardening process - subsequent finishing is carried out after two weeks.
lime plaster factory production has a ratio of 1:4 (1 - lime, 4 - sand). Often reinforcing and organic components are introduced into the composition. Features of lime mortar:
- high resistance to cracking;
- environmental friendliness and elasticity of the material;
- it has good vapor permeability, which contributes to moderate humidity and a favorable microclimate of the room;
- ease of mixing and application;
- lime mortar dries for a long time.
Important! To obtain a durable plaster, it is necessary to use compositions with reinforcing components.
Cement-lime compounds have a couple of binding elements. Such plaster retained the advantages of each type of mixture and at the same time lost some of the disadvantages.
Distinctive features of two-component plasters:
- lime increases the plasticity of the solution;
- finished surface for a long time suitable for mashing;
- has antifungal properties;
- the solution does not fall off the wall and does not exfoliate;
- good adhesion to concrete surfaces;
- regulation of indoor humidity;
- The disadvantage of such mixtures is its cost.
Important! Contact with lime on the skin can lead to chemical burns, so work must be done in closed clothing and goggles.
Gypsum compositions suitable for leveling indoor walls. Such plaster is used in rooms with a moderate level of humidity, for a bathroom or pool gypsum mortar won't fit. The advantages of plaster based on gypsum include:
- plasticity of the mixture - the applied solution does not drain;
- compared to cement composition gypsum leaves less dirt in the process of plastering walls;
- relatively low material consumption;
- the speed of drying of the finished solution;
- good heat and sound insulation qualities;
- suitable for "pulling" strongly curved surfaces.
Cons of gypsum compositions:
- instability to mechanical damage;
- tendency to abrasion;
- with an excess of moisture, the plaster layer deteriorates;
- the solution dries very quickly, so it must be kneaded in small portions and quickly consumed within forty minutes.
Plastering of concrete walls: technology and work procedure
Preparatory work
Getting started, you should prepare tools and materials:
- brush and scraper for cleaning the wall;
- jackhammer or hatchet;
- spatula medium and wide;
- rule;
- building level / plumb;
- beacon profiles;
- plaster trowel;
- falcon;
- container for mixing the solution;
- corner equalizer;
- plaster spatula and trowel;
- grater;
- reinforcing mesh;
- dry plaster mix or components for self-mixing;
- primer.
The process of plastering concrete walls with your own hands begins with surface preparation:
- Loose and exfoliated fragments of the wall must be removed. If this is not done, then later they will cause the destruction of a new layer of plaster. Areas that lend themselves to pressure also need to be cleaned off. The substrate to be plastered must be absolutely stable.
- Cleaning of concrete. Remains old paint, whitewash and putty clean off the wall with a spatula.
- Seal the existing potholes with a solution of sand and cement, and after drying, sand with coarse-grained sandpaper. Restoration of cracks and holes with an area of more than 5 sq.cm. requires the use of reinforcing mesh.
- The walls of a new, just rebuilt house must be cleaned of formwork grease and various sagging. Cut off protruding sections.
- With the help of a brush, a broom or a rag, get rid of tar, grease stains and dust. Effective Method cleaning - blowing with compressed air or thorough washing of the surface under the pressure of water.
Advice. To improve grip plaster mortar With smooth surface, it is desirable to make notches on a concrete wall. This work is done with a hatchet, jackhammer or a chisel.
Applying a primer
Some experts claim that the notches on the base are the last century. This complex procedure can be replaced modern materials concrete wall plasters, e.g. primer deep penetration concrete contact.
The basis of the soil is polymers and a cement-sand mixture. The impregnation components create a bonding rough layer, so that any finish can be securely fixed on the concrete surface.
Betonokontakt is applied to a clean base with a brush or a wide roller. The approximate drying time of the soil is up to 4 hours. Subsequent work is recommended to be carried out without waiting for the complete solidification of the primer layer.
The use of concrete contact has a number of additional advantages:
- Possibility of application of impregnation for external and internal works.
- Safety acrylic compounds concrete contact primers.
- The solution does not interfere with the natural circulation of air in the room and allows the walls to "breathe".
- The primer composition is resistant to mold and fungus.
Fixing the reinforcing mesh
To avoid the formation of cracks due to the thermal expansion of the working solution and the wall surface, it is necessary to install a fiberglass mesh between them. Optimal size cells - 5 * 5 mm. Thanks to the reinforcing mesh inside the plaster, an internal frame is formed that increases the strength of the finish.
The mesh is laid out over the primer layer, stretched well and fixed on the wall surface.
surface plastering process
Immediately before plastering the walls, it is necessary to check for evenness, install beacons and prepare a working solution. It is enough to mix the purchased mixture with water in the proportions indicated on the package, and mix thoroughly with a construction mixer.
You can make a cement-lime mortar yourself according to the following instructions:
- Prepare the components of the mixture: 1 part of cement, 2 parts of lime, 7 parts of lath sifted sand.
- Lime combine with water and mix until smooth.
- Add sand to cement and mix them.
- Mix a dry cement-sand mixture with a mushy solution of lime.
- To adjust the density of the composition, you can add water or sand.
The technology of spraying plaster on a concrete surface can be divided into three main stages. Let's consider each of them in detail.
Stage 1. The first plaster layer is applied to the wall using the "spray" method. The consistency of the solution should resemble thick sour cream. The optimal thickness of this layer is no more than 5 mm. The main task of primary plaster is maximum penetration into the pores of concrete and the creation of a reliable adhesion of materials. liquid solution does not smear over the surface, but is thrown onto the wall in small portions.
Stage 2- application of the main layer with a thickness of about 1.5 cm. Re-applying the plaster is carried out after the previous one has set. The order of surface treatment is from top to bottom, starting from the corner of the wall. The solution should be slightly thicker than the first layer. The entire area must be covered with the mixture, and the excess composition should be removed by the rule by running the tool over the beacons.
Stage 3. Finishing layer plaster should have the same consistency as the second. The thickness of the "cover" is 2 mm. Important conditions obtaining a smooth, flawless surface - the absence of lumps in the solution. To prepare the mixture, sand is taken, passed through a sieve with cells of 1.5 * 1.5 mm.
Before the covering layer is completely dry, the plaster should be wiped off. Traces of the movement of the grater can be removed with a felt cloth.
Do-it-yourself plastering of concrete walls: video
Depending on the material from which the walls are made, there are also ways to finish them. So, despite the apparent simplicity, the plastering of concrete walls is a rather complicated undertaking, in the implementation of which it is necessary to adhere to certain rules and recommendations.
Often, concrete walls are curvilinear, so before finishing they need to be plastered.
Today, concrete is a fairly common material, characterized not only by good performance, but also by the curvature of the surface. That is why do-it-yourself wall alignment with plaster is necessary to give the apartment an aesthetically attractive look. In addition, severe tilting and cracks can be eliminated in this way.
Preparatory work for plastering
Before you start applying plaster, you need to thoroughly clean the walls.
The advantages of plastering are difficult to overestimate. The plaster not only protects against moisture, allowing air to pass through and being able to breathe, but also gives the treated surface excellent heat and sound insulation characteristics. Using different kinds plaster, you can get a variety of surface textures.
When starting work on applying plaster to concrete, it is necessary to take into account the importance of these works: a smooth and durable surface is a guarantee of the quality of the coating for the entire period of its operation. If the work is carried out correctly, the plaster layer will last a long time without cracking or crumbling.
Before plastering concrete walls, the following conditions must be met:
- the surface of the walls must be thoroughly cleaned of dirt and dust;
- concrete must be rough.
In order to process the walls with your own hands, you need to prepare the following materials and tools:
- scrapers and brushes;
- putty knife;
- chisel or jackhammer;
- hammer;
- plaster;
- fiberglass mesh;
- level and plumb;
- rule;
- slats to be used as beacons;
- primer.
Wall preparation technology involves the start of work with the removal of the old decorative coating(paint or wallpaper). It is usually done with a spatula. Then the entire surface is carefully tapped with a hammer to identify loose plaster or putty. In those places where the coating should be replaced, the blows will be sonorous. The lagging putty is removed from the concrete walls with a spatula.
This process will create a new base that guarantees a strong adhesion of the plaster layer to the concrete. If work is carried out in new buildings where plastering has not yet been carried out, care must be taken to clean the walls from formwork lubricant. This can be done with brushes and scrapers or plain water supplied under high pressure.
When the surface is cleaned, notches should be made on it, which will allow the concrete to more firmly connect to the plaster layer. Usually notches are applied with a jackhammer, but in case of its absence, a chisel or a scarpel can also be used.
Back to index
Carrying out priming work
Plastering of concrete walls cannot be carried out without preliminary priming of the surface. It is the primer that allows you to increase the reliability of the structure and extend the life of the finish.
The primer significantly improves the adhesion of the plaster layer to concrete, the putty layer to plaster, and the paint layer to putty.
The primer of the walls is necessary to improve the adhesion of the plaster to the concrete.
In addition, the application of a primer composition can improve surface properties. Concrete becomes more moisture resistant, less susceptible to fungus and mold, rotting and other negative factors. It dries faster after applying the finishing layer.
For monolithic concrete walls with a dense structure, a mineral-based primer is usually used, in which cement is a binder. Experts recommend using a primer, which is called concrete contact. This material is able to stabilize concrete walls for the application of gypsum and other plasters.
Back to index
The use of mesh in plastering work
Plaster mesh is used when the plaster layer exceeds 2 cm.
When the layer thickness plaster composition exceeds 2 cm or there is no confidence in its strong adhesion to the base, it is recommended to use a special plaster mesh. Such a fiberglass mesh can have a different cross section, but it is desirable that the cell size does not exceed 5x5 mm.
By applying the grid, an internal frame is formed that holds the layer of plaster on the concrete. It is necessary when finishing concrete walls with your own hands in rooms where there is a high temperature difference and humidity indicators and the risk of mechanical stress.
The mesh laid on the primer layer should be as tight as possible, otherwise the mesh will begin to vibrate and the plaster will soon crack and fall off. To protect the mesh from corrosion, it is recommended to paint it before use. oil paint or cement laitance.
