Despite the rapid development of the construction industry and the emergence of the latest methods of decorating buildings and structures, none of the alternative decorating methods is still able to compete with traditional plastering of walls. This is due to the undoubted advantages of the method and its features, as well as the ability of plaster to create a protective finishing layer on the surface of the treated walls, which helps to smooth the surface and create a decorative cover. Using plaster, you can fill the foundation for a building, erect a wall or finish it, as well as eliminate the existing errors - for all these activities, a solution for plaster is needed. However, for each of these areas, various types of stucco mortar are necessary - in the process of finishing work, lime mortar for plaster will be required, for the masonry of the wall - masonry mortar. And these are far from all existing varieties of plaster mortars. Construction stores offer consumers to purchase a ready-made mixture for the preparation of plaster, surprising consumers with the variety of these products. In order not to doubt the quality of the solution, you can prepare it yourself, while saving a substantial amount of money. To understand the essence of the issue and get acquainted with various types of plaster mortars and methods of their preparation - read our article.

  What is plaster? Main components

Plaster- This is a rough facing material, with the help of which they smooth out surfaces of various purposes - walls, ceilings, foundations. Depending on the style you have chosen for finishing the surface to be treated, various components can be included in the composition of the plaster, however, regardless of the purpose of the plaster, the following components must be included in its composition:

• Binderincreasing the adhesive characteristics of the plaster and its bonding properties;
• Filler,   designed to relieve internal stress between the particles of the binder components, as well as to increase the volume of the solution;
• Waterdesigned for soaking and mixing the components of the solution. Masters who do not have sufficient experience in this field do not have a clear idea of \u200b\u200bthe difference between these or those types of mortar for plastering walls, if they consist of the same fundamental components. In addition, among amateurs, it is often believed that you can start work by mixing cement with sand and water. However, experts assure that this is far from simple and offer you the following recommendations.

Depending on the purpose of the plaster, it is customary to add the following components to its composition, each of which plays a role and gives the solution additional characteristics:

Lime   added in cases where it is necessary to give the solution additional viscosity. The lime used to prepare the solution may be slaked or quicklime, ground or multi-colored. It is a fragile material with a long drying period, as a result of which lime mortars are used for finishing work exclusively in dry rooms;

Gypsum   or alabaster also does not have significant strength, but is characterized by a high solidification rate. This material is advisable to use for the implementation of minor finishing measures and as an additional component to the mortar, which will increase the speed of drying;

Cementit is a high-strength material resistant to atmospheric influences preserving its original characteristics after contact with water. Resistance to mechanical stresses is another important advantage of cement. Plaster based on cement-sand mortar is used for external decoration of walls of buildings, as well as surfaces located in areas of high humidity;

Clay   - Another component used as an additive to the mortar for plaster in order to increase its viscosity. Such compositions are an ideal choice for plastering and masonry furnaces, due to the fact that after firing, the solution, in which clay is present, becomes as strong as possible;

Sand   in the composition of the mortar for plaster is used as a filler, due to which the volume of the mixture increases. For solutions intended for various purposes, various types of sand are used, however, river sand has the highest efficiency, which is sorted and sieved before being added to the solution.

The main varieties of mortar for plaster: proportions of ingredients

In accordance with the predominance of certain components, the following types of plaster solutions are distinguished:

• Lime mortar for plaster, to reduce the hardening time of which, sometimes use gypsum;
• Cement mortar for plaster, with the preparation of which often there are no unnecessary questions;
• Lime-cement mortar for plaster, which includes three components: lime dough, cement and sand;
• Gypsum-gypsum mortar for plaster, combining optimal viscosity and hardening speed;
• A clay mortar for plaster, in which you can add some minor components to give the mixture the necessary qualities.

For each of these mortars, stucco is characterized by its own proportions, observing which, you can create the optimal working mixture.

One of the most popular mixes for decorating is lime mortar consisting of slaked lime, which is soaked in water, and sand. The ratio of mass fractions of these components looks like 1: 2, less often to 5;

Plaster cement mortar   consists of cement and sand, with a mass fraction ratio of 1: 3 (4). To prepare the solution, the resulting dry mixture is poured with water;

For cooking cement-lime mortar   cement and sand taken in a ratio of 1: 3 (4), as well as a lime slurry, which is slaked lime, diluted with water to a milk consistency, will be required;

Gypsum-gypsum mortar   for plastering, it is an ordinary lime mortar consisting of a mixture of sand and slaked lime, as well as gypsum. The ratio of the mixture of lime and sand to gypsum is 1: 0.3;

Clay solutions   For plastering, they are most often prepared with the addition of minor ingredients such as cement, sand, gypsum or lime. The choice of one or another component depends on the subsequent use of the solution. Approximate ratios of components in clay mortar for plaster are as follows:

• Clay and sand in a ratio of 1: 2 (5), which depends on the viscosity of the clay;
• Clay, lime and sand in a ratio of 1: 0.3: 4.

To prepare the solution, you need to add water to the dry mixture, the volume of which depends on the required viscosity of the solution.

Important! Before you start preparing the solution, you need to make sure that you need to use this particular mixture. For the greatest reliability, it is required to evaluate the physicochemical properties of the solution and the place of their use. In the case of the wrong choice of component composition, this can cause a decrease in the operational characteristics of the treated surface.

Thus, the choice of ingredients depends on:

• Type of work (mortar for external plaster should be resistant to high humidity);
• The external conditions under which the operation of the building or premises is carried out. These include: temperature, humidity, the presence of aggressive external factors;
• The material from which the surface to be plastered is made.

Types of plaster depending on the proportion of ingredients:

Given the proportions of the fundamental components, the stucco mortar can be divided into three types:

• Fat solution, the composition of which is dominated by a binder component. After drying, such a solution is prone to cracking;
• Normal solutioncharacterized by the optimal ratio of filler and binder;
• Lean solution, which is characterized by a small amount of filler, and therefore, it is short-lived and fragile.

To determine the type of solution, you only need a trowel and a little observation. Dip it into the solution and see:

• If the solution sticks to the trowel in pieces - the solution is oily;
• If the trowel only got a little dirty - the solution is skinny;
• If the solution lies on the trowel in the form of a thin crust, the ratio of binder to filler is normal.

Important!   You can reduce the fat content of the solution by adding filler to it, while you can increase the viscosity of the lean solution by adding a binder.

  The composition of the mortar for plaster: general requirements

What to look for when choosing the composition of the mortar for plaster? First of all, it is important to follow the provisions below:

• To plaster concrete and stone facades, which are constantly exposed to moisture and precipitation, experts recommend the use of Portland cement and slag Portland cement to prepare a mortar for plaster;
• If stone and concrete facades are not constantly exposed to moisture, it is recommended to use mortars for plastering, which are based on the use of lime and cement, as well as other binders based on lime;
• For the finishing of wooden and gypsum surfaces, lime mortars are used, the composition of which is recommended to include alabaster to increase the speed of the mortar;
• The solution for the internal plastering of rooms with high humidity (the humidity level during operation is above 60%, which is typical for a kitchen, bathroom or bath), the first layer is applied from a cement or cement-lime mortar.

  Decorative characteristics of the mortar for plaster: what to look for?

Often, experts recommend paying attention to decorative mortars for plaster, which can be used both for interior decoration of the walls of the room and for the decoration of facades. In the process of manufacturing decorative solutions, it is recommended to use the following substances as an astringent:

• Traditional, white and colored Portland cement for finishing facades and walls indoors;
• Gypsum and lime, intended for color plastering of walls indoors.
• In the process of manufacturing decorative solutions, the use of marble, granite, dolomite, tuff and various fractions of limestone is widely practiced;

Important!   To enhance the luster of the plaster composition, not more than 10% of ground glass and 1% of mica are added to its composition. The practice of adding dyes - alkali-resistant and light-resistant pigments of natural origin, such as chromium oxide, ultramarine, ocher, red iron and other known substances.

  How to make a mortar for plaster: preparatory measures

First of all, it is necessary to prepare a container for mixing the solution, the volume of which depends on the required amount of solution. Experts recommend giving preference to such a tank, the configuration of which will provide a complete sample of the solution. In the event that the container is characterized by a complex configuration, the solution will solidify in the bottom and in the corners of the vessel, which will subsequently lead to difficulties in subsequent attempts to knead the solution. Experts recommend choosing containers with a large bottom of the pallet, and therefore, it is not recommended to use a bucket as a container for mixing the solution.

In addition to the capacity, it is necessary to prepare the following materials and tools:

• Dispenser, which can be used any capacity of any volume;
• Nozzle for a drill (the so-called mixer), designed to mix the components of the solution. If you do not have a nozzle for a drill, you can manually mix the solution using a trowel or other improvised tool;
• Binder (clay, lime or cement);
• Filler (sawdust or sand);
• Water.

  Preparing the mortar for plaster: a step-by-step guide

Before answering the question: “How to make a solution for wall plastering?”, It is necessary to answer that the solution is prepared in several stages, the first of which involves preparing a dry working mixture, and the second - adding water to it and actually mixing the solution. There are two ways to prepare mortar for plaster: manual and mechanized.

  Manual method of preparing plaster

It involves mixing a dry binder, during which the following rules must be observed:

• The first and most important requirement is the capacity requirement. Its bottom should be even and clean;
• Sand is poured into the bottom of the tank in the form of a continuous layer or in the form of small piles;
• The binder is distributed evenly over a layer of sand;
• The mixture is stirred and leveled with a rake;
• The last two points must be repeated several times.

Important! If the mixture is not sufficiently mixed, its color will be characterized by heterogeneity and the presence of bands, while the uniformity will be the criterion for the quality mixing of the composition.

  Mechanized method of preparing plaster

To save time and effort, for mixing the solution use a nozzle for a drill or, so-called, mixer. For a mechanized method of preparing a mortar for plaster, the consumption of which largely depends on its composition and quality characteristics, you will also need a bucket or any container that replaces it. The necessary components are poured into it in the right proportions depending on the type of solution chosen and, using a mixer, mix it to a homogeneous consistency.

  How to prepare a cement-lime mortar for three-layer plaster?

Most often, on the construction sites, the use of cement-lime mortar is practiced. They are intended for the installation of external and internal three-layer plasters. To properly prepare such a solution, you need to know the requirements for the composition and consistency of each of the three layers, as well as their other specific features.

The first layer of plaster is spray.Its application is carried out on a pre-prepared surface so that all pores of the treated surface are filled. The application of this layer is carried out in order to increase the adhesive characteristics of the treated surface, that is, to increase the adhesion strength of the base with a layer of plaster;

Important!   The solution intended for spraying should be appropriate, creamy consistency. The thickness of the mortar on the ceiling does not exceed 4 mm, on the walls 3-4 mm. The spray solution can be prepared only with cement without adding lime, however, if you are working in rooms with high humidity, it is necessary to prepare a cement-lime mortar.

The second layer of plaster is soil.   The thickness of this layer should not exceed 15 mm, and its application is carried out only after the first layer - the spray will begin to set, but not yet completely harden. The solution intended for soil should be of the appropriate consistency, reminiscent of a steep dough. The middle layer of plaster is leveled with a trowel or lath, but in order to ensure a more comfortable application of the final plaster layer, experts recommend leaving some roughness and unevenness on the ground;

The final finishing layer is a coating. To prepare the solution applied at this stage, fine sand is used. At the same time, lime is added to it, and in larger quantities than at the previous stage. Thanks to this trick, the solution acquires a more plastic consistency. The topcoat is applied with a thin layer (no more than 3 mm), after which it is carefully leveled with a trowel or a smoothing trowel.

Plastering is an integral part of any repair work. Thanks to this process, the consumer properties of the processed surfaces are improved, the reliability and durability of the walls are increased. Qualitatively prepared and correctly applied plaster prevents the spread of mold and fungi, removes all bumps, chips and mechanical defects, and also helps strengthen the base.

  Features of plastering - 3 layers

The solution for plastering walls is easy to do with your own hands. It is necessary for leveling the surface. This operation is required both when conducting external decoration, and internal. The characteristics and requirements depend on the place of application of the essence. So, to carry out repair work inside the premises, a technologically advanced and plastic mass will be needed, while the external mixtures should be primarily resistant to pressure and temperature changes, frost-resistant and resistant to moisture.

Solutions are applied on surfaces of all types and types. Plastering of plywood, chipboard sheets, wooden elements, cinder blocks and foam concrete, masonry, concrete. When manufacturing a suitable composition at home, it is very important to pay attention to the adhesion of the finished product when choosing components and proportions.

The correct technology for applying plaster to the ceiling and walls includes three main steps:

• Spray is the first coat to be applied to a building foundation. It is necessary to fill and align the largest pores and surface defects, as well as to ensure the appropriate level of adhesion and adhesion of subsequent plaster layers. During its formation, additional elements, such as lime and clay, are not used, and the coating thickness should not exceed 4 mm.
• The second level, which was called soil, is significantly larger in volume than the previous one and reaches 20 mm. Unlike liquid spray, this layer with its consistency is more consistent with a thick plastic test. Its task is to maximize the alignment of the base plane, regardless of its roughness.
• The last stage of the work is the application of a coating on the surface, which is required to finish smoothing irregularities and base defects. The thickness of the layer is from 3 to 5 mm, but water is added so much to achieve the maximum level of plasticity and viscosity of the solution. After covering, it remains only to whiten or paint the walls or to glue decorative wallpaper on them.

  What components are needed to prepare the mixture?

Many beginners, trying to make a plaster solution with their own hands, from the very beginning violate the mixing process. This is very important, because the key characteristics of the finished composition depend on the quality and proper mixing. The main components include water, aggregate and astringent. If necessary, additional materials are introduced, including various additives and plasticizers.

Clay and lime can play the role of an astringent. But the most popular and sought after is cement. It is great for preparing a mixture, which is later used for exterior or interior decoration. At the same time, it is the most expensive option, because in terms of quality, reliability and strength, the remaining ingredients are seriously inferior to it.

Choosing among many varieties, it is easiest to stop on cement brand M400. This dry mix is \u200b\u200buniversal because it meets all the requirements of GOST, as well as apartment owners. Great for processing bathrooms, kitchens, hallways and, of course, living rooms. If the budget is limited, and repairs are carried out in less responsible structures, such as basements or socles, then the rational decision is to purchase Portland cement M300.

The strength of the plaster is influenced by many factors, but the most important is the brand of cement. The higher this indicator, the better the solution will be.

Having decided on the binder, it remains only to deal with the filler. Here, the only and indisputable favorite is ordinary sand. It is recommended to take a clean river fine fraction, which will ensure maximum mixing of all the ingredients of the future plaster. Together with cement, it forms the ideal material, characterized by resistance to cracking and a high level of strength.

The simplest and most demanded proportion of the preparation of a cement-based plaster mix includes one share of a binder and three parts of sand. This recipe is suitable for almost any room. Water is added to form the essence of the required level of viscosity. For rooms with a normal level of moisture, a little more can be added. If you want to achieve ductility, then the correct ratio implies the use of one portion of cement and two parts of sand.

There are many plasticizers and additives designed to increase the softness and suppleness of the finished plaster, change the curing time and various characteristics of the solution. Home craftsmen often add detergents, soap, adhesives, like PVA. Thanks to such materials, the adhesion of the essence to the concrete base is improved, and the level of protection against fungal bacteria and mold is also increased.

The big mistake is related to the technology of mixing the mixture. For some "specialists" the order of adding components does not matter. Many first pour water into a container, then pour cement, sand, lime and other materials. The problem is that the dry matter, after getting into the liquid, is converted into small lumps. To stir them to obtain the consistency of the required level will require a lot of effort.

In order for the solution to turn out to be high-quality and uniform, experienced craftsmen advise you to perform the following actions:

1. 1. Initially, it is required to sift the sand using a fine mesh sieve. Otherwise, all garbage and large particles, such as shells, pieces of silt, pebbles, organic residues, will be in solution. During plastering, they will leave furrows on the surface of the wall, clinging to a spatula.
2. 2. After that, pour dry cement into the sand and mix everything thoroughly. If the filler is wet, then it will need to be dried - mixing will be an order of magnitude easier when both components are dehydrated.
3. 3. Only after this is water added, and gradually, while the solution itself is constantly mixed. It is recommended to pour in new portions of liquid at that moment in time when it is almost impossible to interfere.

  Types of plaster mortars - different options

For the preparation of mixtures for the treatment of external and internal walls, many different components are used. So, the solution in which cement and lime acts as an astringent boasts great popularity. This essence perfectly tolerates low temperatures, exposure to direct sunlight, counteracts the appearance of mold and fungi.

Unlike conventional cement plasters, calcareous analogs have a high level of ductility and viscosity. This positively affects their adhesion index, due to which they instantly and firmly grasp the bases of walls and ceilings of any type and type.

In rooms with normal humidity, it is worth using lime plasters, which quickly dry out and absorb excess moisture. In the best way, this composition has proven itself for brick surfaces. The lack of cement affects the strength and reliability of the mixture, in addition, it hardens within three days. But this factor allows you to prepare quite large volumes of essence, because if you want, you can always add water if the substance in the tank begins to solidify.

It is recommended to use additives, such as gypsum, for coating and processing wood, stone and fiberboard. In combination with cement and lime, the plaster is very strong and ductile, but it will not work for wet walls. The presence of this substance leads to a high solidification rate, which makes it impossible to prepare the mixture in large volumes or to “revive” using ordinary clean liquid.

Very popular are decorative cement mortars and glazing plasters, which require additional investment of money and effort. Using these mixtures, you can finish the halls, corridors and hallways. In addition to the main astringent ingredients, many other materials are added, including minerals, mica, slaked lime, marble chips.

If it is necessary to give a certain shade, which is typical for Venetian plaster, it is recommended to pour color pigments. You can buy all of these additives in the same hardware store where bags of cement and lime are sold.

If you plan to apply the decorative mixture in baths or near the stove, you will need to increase the level of resistance and resistance to extremely high temperatures. To do this, it is recommended to add chamotte powders and special refractory clays. As a result of this process, cement with the addition of these materials produces a strong essence that is resistant to heat, so that it can even process the walls of fireplaces.

  What is useful for kneading - let's move on to the tools

Mixing all the components of the solution is carried out in two ways - machine and manual. The easiest way to prepare the mixture is in an ordinary enameled bucket or other similar container. Adding cement and sand and mixing everything thoroughly, it remains only to pour water in small portions and continue to knead the composition with the help of improvised tools.

If you want to make a large volume of the solution, it is recommended to use a special trough or bathtub. Here, for mixing the components, blunt shovels or bayonet shovels are used, as well as choppers with a flat base. To simplify the process a little, experts advise to perform movements on themselves, otherwise the arms and lower back will get tired too quickly.

If there is a construction mixer, then it greatly simplifies the work. The nozzle is any suitable element, whether it is a curved wire or blade. Concrete mixers also make it easier to mix the mortar, but their operation is advisable only if the volume of the plaster is very large.

When choosing plaster, it is worthwhile to find out which solution is suitable for coating and leveling walls. The type of this material depends on the base from which the walls are made, as well as on where the plastering will be performed - from the inside or from the outside.

First you need to determine the features of the indoor microclimate. To cover the walls are often used mixtures of cement or with the addition of lime. If the house or apartment has dry conditions, then it is better to use lime type plaster. These mixtures can also be used to cover interior walls under moderate climatic conditions.

For wall decoration, the following types of mixtures can be used:

• with cement structure. This species is slowly gaining strength. Typically, the solution sets in half a day after introducing the mixture into water. If we compare it with other varieties of plaster, then it is characterized by increased strength;
• with clay composition. Clay mixes are intended for leveling wood walls;
• with lime composition. Mixtures with this composition are suitable for coating internal and external walls of virtually any material. Sometimes gypsum material is added to the composition of this mixture;
• gypsum. This material can be used independently without combining with other types of plaster. But be sure to remember that the hardening of the coating is observed after half an hour. After about 4 minutes, the solution sets;
• combined mixture. Two binders can be used in the composition at once - cement and lime, lime and gypsum, etc .;
• special mixes. The required additives are introduced into them.

Brand of mortar for plaster

The strength level of the future coating is determined by the brand of mortar for plastering the walls. This indicator means temporary compression resistance, it is measured in kilograms per cm2.

Solution components and proportions

Grades of the solution are divided into the following types and proportions:

1. M50. This is an easy composition. It is usually used to grout small defects, bumps. It has low strength, but at the same time it has minimal shrinkage. This quality is important when applying the topcoat. Proportions: when using cement M400, the proportion of proportions should be as follows - 1: 6.3. 6.3 parts of sand must be added to one part of cement;
2. M100. This is a dense composition that is used for the internal coating of wall surfaces. The proportions in the preparation of the solution should be such, one part of cement and 5 parts of sand;
3. M150. The brand of solutions is used for decorating rooms with damp and high humidity, as well as for covering facades, basement floors of buildings. When mixing, 1 part of cement and 3 parts of sand are taken.

If the brand of cement mortar is incorrectly selected, this can lead to premature destruction of the coating. It can quickly crumble, exfoliate, and crack due to shrinkage. It can also cause increased material consumption and high financial costs.

The rate of consumption of cement-sand mortar

In order to understand how much sand and cement to use, it is necessary to look at the marking of cement. Since cement is a bonding component, and sand is a filler, the first should be one part, and the second several.

First of all, it is worth calculating the approximate size of the thickness of the layer of the future wall covering. For example, there is a surface with an area of \u200b\u200b10 square meters, the deviation of which is 5 cm. In these cases, when calculating, it is worth following the following recommendations:

• using a plumb line you need to identify three points with deviations - 1, 3 and 5 cm;
• the received data is added, and it turns out 9;
• further divided by the number of checked points, it should turn out 3.

As a result, a layer thickness of 3 cm is obtained. If the wall has slight deviations, then the layer thickness should be at least 6 mm, because this is how beacons depart from the wall.

After that, we calculate the amount of solution, for example, there is 8.5 kilograms of dry mix. This volume of the mixture is multiplied by the size of the layer thickness, by 3 cm. The result is 25.5 kilograms per 1 square meter. Then for 10 square meters it will take 255 kilograms. Since the mixture is supplied in bags of 50 kilograms, then 255: 50 \u003d 5.1. But it’s better to round up, so you need to buy not 5 bags, but 6.

How to adjust the strength

The rate of consumption of the cement mixture can vary within the same brand.

Therefore, you should not focus solely on the indicators of the binder material and components for filling, because these data cannot reliably determine the strength characteristics of the solution.

There are several reasons that weaken or strengthen the mortar, and they can also change the amount of cement mix consumption:

• fractions of the component for filling. As a rule, the cement material completely envelops the particles of the filling element. The smaller the size of the filler particles, the higher their indicator of the total area of \u200b\u200bcontact with binders. The conclusion follows from this, the smaller the particle size of the filler, the more cement material is required;
• the strength of the filling material affects the quality of the solutions. If rocks are used together with sand in a ground state, then an increase in mass strength by almost 1.25-1.5 times will be observed;
• the plaster has a similar composition, but the mortar strength is higher. Therefore, the amount of water and binder must be taken into account. In order for the normal chemical process to harden the binder component, namely cement, a little fluid is required. In this case, the calculations are performed as follows - the mass of water is divided by the mass of cement, which is added to the solution. The required indicator should be 0.15-20.

Approximately 17-18 liters of water are required per about 30 kilograms of dry mix, if you add more, for example, 20 liters, then a sufficiently liquid solution can come out. And if you pour 25 liters, then the strength properties of the solution are reduced to a minimum. At the same time, indicators of cement and sand do not play an important role.

The main indicators when mixing the solution are the type of binder component, namely cement, the level of strength of the filler (sand) and the volume of liquid used. Liquid solutions are quite convenient to use, but they have low strength and short service life.

How to knead

Kneading a solution is just mixing, but the strength of the further wall coating will depend on how this process is completed. If the batch is made poorly, unevenly, then not all particles of the filler will be covered with cement. Therefore, it is important to strictly follow the step-by-step preparation of the solution:

1. At the initial stage, sand is poured into a prepared container. It is necessary to sift sand through a sieve, this will help get rid of gravel, clay particles, shells and other large elements;

For sifting sand for a primer coating, it is recommended to use a sieve with mesh sizes of 2-3 mm, and for nakryvochny - 1 mm. For sifting, you need to use dry sand.

1. Next, cement is poured into the sand and mixed with it. All components must be completely dry;
2. At a subsequent stage, water is poured. To begin with, pour 2/3 of the water and stir as much as possible, and only then pour the rest of the water. Everything is thoroughly mixed until a homogeneous consistency is obtained.

What affects the strength of the plaster during its hardening

For a quality hardening reaction to take place, there must be a positive temperature of 15 to 25 degrees Celsius.

The drying of the coating can be greatly affected by changes in weather conditions:

• cold. When cooling the plaster slows down the chemical and physical processes. In these cases, a slow hardening of the coating occurs;
• freezing a layer of plaster. When freezing, particles expand inside the plastered wall coating. Expanding ice crystals lead to rupture of already seized components. After thawing, the hardening is repeated again, but this does not apply to already exploded particles;
• exposure to heat, as well as increased evaporation of moisture from the surface of the plaster causes difficulties in the course of the reaction. There is a lack of fluid, solidification does not proceed completely, and sometimes it stops altogether.

Additives

When mixing the mortar for plaster, sand can be added as a filling. The following types of sand are optimal:

1. River sand. This species is considered the most purified. Water flushes out foreign, unnecessary components with an insoluble structure;
2. Quarry sand. It has jagged and sharp edges. These qualities increase its strength characteristics. However, in its composition, a high content of clay can be observed, which can lower the level of rigidity of the final petrification.

To prepare the solution, do not use sand of brown, yellow, red color. These colors indicate that the sand contains an increased level of alumina, which reduces the strength characteristics of the material.

The better to knead

Mixing the solution can be done in different ways, it all depends on its volume. If you need a little mortar, for example, for grouting or for lubricating uneven walls, then it can be kneaded in a bucket. Kneading can be done manually with improvised tools - a spatula or trowel.

To facilitate mixing, you can use special tools - mixers, nozzles on the drill. In the form of nozzles, special blades or a curved part of the wire can be used.

If a larger volume of solution is required, then a large trough or bath will be required to prepare it. Kneading can be done manually with a flat blade chopper.

But the easiest and easiest option would be to use a concrete mixer. If you need to perform a large amount of work, then manual kneading will be very time-consuming, for this reason it is better to purchase a concrete mixer, in which it will be easy to knead the solution.

In any case, if you plan to finish the walls in the house, then study all the features of this process in advance. It is necessary to know all the nuances of its implementation, so that in the future the coating does not quickly crumble and does not crack. The right choice of material, the exact observance of proportions when kneading and the correct application of the solution - this is the key to a high-quality and durable wall coating.

The video describes the process of preparing a mixture for plastering walls indoors. It tells you what materials you need to use, and in what proportions.

Good plaster, like a good bricklayer, has a lot of its own secrets about which walls and in what proportion to prepare a solution for plastering the surface. Most of the good specialists are avid conservatives and are used to using not ready-made building mixtures, but sand and cement mixed in certain proportions.

Kneading solution

For an amateur plasterer, fussing with the preparation of a stucco mortar with your own hands is much more difficult. It’s easier and more reliable to hire a specialist. But still, most of us are ready to take risks and try cement, clay or lime mortar for plaster, for example, for a garage or a summer residence.

Plaster mortar based on the simplest proportions of cement, sand, clay or lime is considered most suitable for private houses and apartments. In this composition, but in different proportions of the components, you can:

• Plaster bare brick or cinder block walls of a freshly built country house, garage, barn;
• Repair a crumbling piece of plaster both inside the building and outside the house;
• Make major repairs in the old (new) apartment with the removal of the old plaster and applying a new one on the wall.

With the right proportions and technology for laying the plaster, a layer with a thickness of 10 to 20 mm should:

• not to lag behind a brick or concrete base, not to crack, burst or to be removed with one "cake";
• provide good vapor permeability, but do not allow moisture to penetrate deep into the walls, be resistant to temperature and moisture.
• If you have ever prepared do-it-yourself mortars for bricklaying with your own hands, then you can also handle the preparation of the composition for wall plastering. The work is almost the same, you just need to select the proportions for each case individually.

Do it yourself do-it-yourself cement-sand batch for home plastering

In a private house or apartment there are three main types of premises, each of which requires its composition and proportions of plaster. All basic options are cement based. Pure clay or lime mortars will not be able to provide the necessary properties of the plaster.

Stucco for living quarters

Any living room according to sanitary standards should be well ventilated, be consistently warm and comfortable. Therefore, the walls and ceilings of any living rooms should be plastered with solutions containing in proportion:

1. For a bedroom, a hall, a nursery, 2 parts of cement of the 500th or 400th grade are taken, coarse sand - 6 parts, lime - 1 part. The first, rough layer can be done with 1 part of good gypsum added, then in the final proportion for plastering, replace coarse sand with fine-grained sand and add 1/10 of the plaster mass of liquid polyacetate glue;
2. For the kitchen, corridor, pantry, bathtub or toilet, proportions are used - 4 parts of sand and an adhesive additive are added to 1 part of cement, plaster is applied in one, as thin layer as possible;
3. For rooms requiring maximum wall insulation, in specified proportions, instead of lime, you can use greasy clay.

Advice! For the plastering of hot surfaces associated with a stove, fireplace or chimney, lime is not used in the proportions of the mortar for plaster; the main batch is made on clay and sand.

If the layer of such plaster turns out to be very thick or fragile, which happens with lean grades of clay, use a solution of sand, clay and cement in a ratio of 4: 8: 1. To increase the strength, sometimes 10% of ground mineral fibers or chopped asbestos are added to the solution. But in this case, it is impossible to use such a mortar for plaster in residential premises, only in the attic, in the boiler room or in similar buildings.

Proportions of plaster mortars for outdoor use

Good, just golden, the rule says - you can not plaster the outer walls at sub-zero temperatures, windy weather or in direct sunlight. The plaster of even the most correct proportions may not immediately fall off, but it will definitely not be held firmly and confidently. With strong drying under the sun, the applied layer of plaster is sprayed with water from a garden sprayer or an ordinary wet broom.

The proportions themselves for the stucco mortar for outdoor work are about the same as for internal work, but with a halved amount of lime.

The technology of work is somewhat different. First of all, we apply plaster in several stages.

At the first stage, wet soil is performed. This means that a thin, a couple of millimeters plaster solution is sprayed onto the cleaned surface. Weight proportions - for 20 kg of 500th cement 4 buckets of washed river sand and two liters of glue base. Sometimes, in the case of plastering a smooth concrete surface, 100 g of detergent is added to the batch for better adhesion to cement.

The next layer of plaster without detergent, with an increased proportion of sand to 5 buckets and a small additive, 10-15 kg, of the smallest mineral fiber. At this stage, a maximum layer of plaster is applied to the walls, finally leveled and prepared for the final operation.

After 10 hours, you can apply the top coat. The proportion of sand can be increased to 6 buckets, but at the same time use the material in the finest fraction possible. After finishing grouting and smoothing, the wall finally dries for at least two days.

Note! In exterior and interior plastering, each new layer reduces the strength of the entire plaster.

The most durable and strong in proportion to the amount of cement laid is the soil, then each new layer should be with an increased content of sand and lime.

In addition to proportions, in the plaster it is very important to correctly apply the material to the surface, often this is done in the form of separate pieces of mortar, with the force of the walls pressed or poured onto the surface.

What cement and sand is better to use

For plastering works, sand that is clean of clay and inclusions is used. If it is not possible to wash the material, it can be sieved several times through building sieves, thereby removing inclusions and selecting the smallest one for the finishing compositions. Coarse and largest sand, as well as gravel, can be used in the appropriate proportion in the stucco mortar.

Portland is taken from cements, brands no lower than the 400th. The higher the grade of cement, the greater the shrinkage and the higher the risk of cracking. Before kneading, cement is always checked for curing and shrinkage after solidification.

If the mortar is not developed during the working day, it is discarded, and can not be used in further plastering work. Specialists do not work with plaster mortars at 30 or more degrees of heat.

Clay and lime mortars for plasters

For internal work, you can use the stucco mass of clay and lime paste, in a ratio of 1: 1, with a small addition of wood dust or shavings. Clay and lime must first be soaked in water in a proportion of 1 part clay or lime in 1.5 parts of water. After absorbing water, both components are thoroughly kneaded and crushed in order to find and remove all the smallest inclusions of stones or foreign inclusions. The components of the plaster are thoroughly mixed and applied to the wall.

If only clay and sand are used for plastering, it is necessary to carefully select their proportions in the composition of the mixture. Clay is a very complex material, its properties strongly depend on the content of hydrated silicon and aluminum compounds. Sometimes masters use pottery techniques to increase clay plasticity. The clay mass is cut with a shovel into ribbons, transferred and mixed. After 5-10 such rifling clay becomes very viscous and durable.

Typically, such solutions close up the walls of the wooden battens, panel structures with insulation and a waterproofing layer. Mixtures of lime, sand and gypsum often plaster walls with gypsum blocks, prefabricated structures of gypsum plasterboard and galvanized profile.

A clay-lime mortar can be stored for several days, dries very slowly, because of this, thick layers of plaster can be deformed, especially in a draft or in cold wet weather. In the most urgent cases, in order to accelerate the drying of the intermediate layer, newspaper sheets are placed on the moist surface of the clay plaster. They slowly take water from the plaster and contribute to its uniform drying without deformation.

Each specialist has his own proven methods of strengthening the plaster layers even with poor proportions or "heavy" walls. Doing such skills with your own hands takes years. Therefore, sometimes you should not waste time imitating the technique of plastering walls, but use the services of masters.

The quality and durability of the entire finish, including the finishing one, which will be carried out on the plaster layer, depends on how correctly selected and prepared the mortar for plaster is used for use indoors or outdoors.

Probably, it doesn’t seem new and everyone knows for a long time that modern stucco mortars using new technologies are made from dry building mixtures, which are closed with the amount of water specified by the manufacturer, l / 1kg of dry mixture.

Yes, such mixtures are popular, because with them you can quickly and efficiently complete the work, but plastering the house with such compounds is not an inexpensive undertaking. The fact is that at a price they are several times, and even tens of times more expensive than traditional formulations due to the presence of all kinds of modifiers, plasticizers and a high-quality, selective filler in them.

So if the construction budget is small, then perhaps it makes sense to use good old cement or lime plaster mortars. Therefore, in this article we will consider traditional mortars, or rather the composition of the mortar for plastering, which contains a list of components:

• astringent;
• filler;
• modifying additives.

The composition of the mortar for plaster may depend on many factors, since each component has certain properties, such as strength, water resistance, frost resistance, setting speed, ductility, and so on.

Among the factors affecting the selection of components for the stucco solution, there are both the type of surface, the purpose of the room and the amount of funds for the plaster, in the end.

Types of binders included in the mortar for plaster, the proportions of the mortar for plaster

A binder for a stucco mortar is a component on which almost everything depends: strength, water resistance, setting speed and, in part, plasticity.

So, for example, the composition of the mortar for cement-based plaster has the highest degree of strength and water resistance compared to the mortar, which, unlike the first, is used only for wall plastering inside residential premises. But the lime mortar is more plastic, therefore, easy to use.

There are also solutions that contain two binders, for example cement-lime or lime-gypsum solutions, which are called complex solutions. To clarify, make a list of binders that are part of the mortar for plaster:

• cement;
• lime;
• gypsum.

In this case, the list of binders is small, it is all of its types that are used in the preparation of modern dry building mixes for plaster mortars, and in the preparation of traditional compositions, the proportions of which we will discuss below for each individual binder.

Cement binder   It is considered the most durable and waterproof.

It is used in the manufacture of cement-sand and cement-lime plaster mortars, which are used for wall decoration inside and out.

There are varieties of cements, such as Portland cement and slag Portland cement, which are most often used in mortar for plaster; There are also pozzolanic varieties of them, including quick-hardening ones.

What is important is the brand of cement used, for example, if you take cement of the M400 brand, then 1 such bag will have four bags of sand for stucco mortars (or other appropriate fine-grained aggregate) so that the grade of mortar leaves M100.

If you take the M500 brand, then it will have five parts of the corresponding filler for the brand of M100 solution. A corresponding proportion is observed in the manufacture of cement-lime mortars.

  It has special properties, the main of which is bactericidal.

Lime inhibits the development of microorganisms even decades after application.

Lime-based solutions are plastic, stick well to the wall and are easily leveled, as well as groutable.

There are two of its main varieties - hydraulic and air. Hydraulic lime is less plastic, therefore, it is harder to work with such a solution, however, it is stronger after setting, and it sets faster than lime.

As for the proportion of mortar for plaster, it depends on the type of lime (there are only three of them), as well as its condition (ground water or lime dough). Today, to a greater extent, the finished packaged lime dough is used for the manufacture of lime, lime-gypsum and cement-lime mortars for plaster.

More often you can find ready-made lime mortars packaged in plastic bags, due to the ability of such a solution not to seize for a very long time.

  It has the best ductility and differs from the previous ones by almost lightning fast setting speed.

There are a lot of varieties of it according to TU (technical specifications), but when it comes to the use of gypsum binder for plastering, then this is a grade of gypsum G-2, G-3, G-4, G-5 with a thin, medium or coarse grinding (grain size), which is called gypsum.

These brands of building gypsum belong to the groups of first and second gypsum binders. The first group is produced by heat treatment of gypsum raw materials of low, medium and high degree of firing.

The second includes materials that are produced using technology that does not contain firing. The calcined gypsum binder used to make the mortar for plaster is marked PG.

Types of fillers that make up the stucco mortar

The filler for the plaster mortar determines in it such qualities as weight, strength, thermal conductivity and decorativeness.

Fillers with different properties and grain sizes are used for ordinary, special and decorative plasters.

For ordinary plaster, as a rule, this is sand, for a special range of fillers is much wider, for decorative use ground fractions of semiprecious stones. In addition, they may contain impurities; grains themselves can be of various shapes and have different densities and much more. Consider the types of fillers for stucco mortar, their list is as follows:

• sand for ordinary plasters;
• sand for special plasters;
• sand for decorative plasters;
• active mineral fillers.

As a rule, fillers for stucco mortars are prepared in advance, sieved at the factory or directly at the construction site, where the preparation of the stucco mixture takes place. Let us consider in more detail each of the data in the list of fillers.

Sand for ordinary plasters   - This is a fine-grained (fine-grained) stone material, which with the help of a binder material forms an integral artificial rock with similar properties.

For the stucco mortar, take ravine or quarry sand with a fraction of up to 5 mm, which contains a minimal admixture of clay or none at all; the grains themselves have an acute shape, which provides better dressing.

However, there are cases when ravine sand is not acceptable - when plastering facades, when the absence of clay impurities is required at all. At the same time, the composition of the mortar for facade plaster contains a filler - river sand, and modern additives are used to improve ductility. Plaster with such a filler has no special qualities, neither decorative nor special.

Sand for special plasters   has special properties. So, serpentite and baritic sands with a grain fraction of more than 1.25 mm and a density of 2400 kg / m3 are used as fillers for X-ray protective plasters.

Quartz sand, as well as diabase flour, are fillers for plasters with resistance to the effects of acids. Metal chips and dust are used as fillers for impact-resistant plaster.

There are also fillers that have a high heat-insulating effect, like perlite sand, which is part of the solution for heat-insulating plaster.

Sand for decorative plasters   happens to be very different. It can be a mineral filler of a fraction of 1.5-4 mm for modern so-called "facade" decorative plasters.

There is a filler thinner than sand - granite and marble flour, as well as other frayed decorative and semiprecious stones.

The composition of the mortar for decorative plaster can contain several different fillers, including decorative and ordinary fillers. There may also be pigments that give the solution one color or another, for example, building black, is also considered a filler for solutions.

Active Mineral Fillers   are substances of natural origin, which not only create the volume of the solution, but also participate in the formation of the crystal lattice, which occurs when the solution sets.

These substances act like an astringent component, enhancing its action, respectively, increasing the brand of the solution.

They can be of natural origin (sedimentary and volcanic) and artificial. Natural sedimentary are diatomites, tripoli, flasks, gliezhy; natural volcanic - routes, tuffs, ashes, pumice; artificial - siliceous waste, burnt clay fuel waste.

Types of modifying additives that are part of the mortar for plaster

Modifying additives for plaster mortar are used to improve its quality. There are universal and narrowly targeted modifiers.

The method of their action is mainly reduced to the interaction with a binder (cement) and the strengthening of one or another of its properties.

But there is another type of additives - filler additives, which in themselves are not chemically active, but having a certain shape, strength and other geometric and mechanical qualities, improve the strength of the plaster itself, respectively. Regarding their functions in solution, modifiers for plasters are divided into such varieties:

• setting accelerators / retarders;
• additives to improve frost resistance;
• additives to improve ductility;
• strength / grade additives.

This list contains supplements of both the old and the new sample. They can be presented in the form of loose or liquid materials that are mixed in advance with water, or are poured directly into the container when preparing the composition for the plaster. Next, we consider these components in more detail and describe their principle of operation.

Set accelerators / retarders   - these are substances that by chemical action slow down (or accelerate) the ability of the binder component in the plaster to form a crystalline network (the ability to set).

So, for example, the composition of the gypsum mortar for plaster takes place by the presence of a setting retarder in it, in this case bone or casein glue acts as a classic moderator.

It is clear that today these additives are presented as complex chemicals that have complex mechanisms of action on an astringent, which allow achieving the desired result.

Additives to improve frost resistance   were before, and now exist.

Along with ferric chloride in the market in the vast majority you can find modern, harmless additives based on special salts. These additives dissolve in water, which shut off a dry mixture of binder with filler.

Their essence is to prevent the water itself from freezing under the influence of freezing temperatures. It is difficult to tell the principle of action, but everyone knows that salt water freezes much more difficult than fresh, therefore the most elementary types of these additives are presented as salts.

Plasticity Additives   very desirable for use in plaster mortars made by traditional technologies.

This is especially true of a simple cement-sand mortar for plaster, which is very difficult to work because of the very rapid loss of water from it, as well as its stratification into water and other components.

The essence of such additives is to retain most of the water in the solution and prevent its delamination. Getting into the water and shaking with all the components of the solution, this additive creates a lot of small bubbles in which water is held for some time.

Strength Supplements / brands of solution can act both in interaction with a binder, and separately. In the second case, from a technical point of view, they themselves are binders, however, their properties are not enough for independent use without the main binder.

In addition, there are separate additives that are not chemically active (do not participate in the formation of the crystal network), but are used as a strong filler (reinforcing additives).

This is the so-called - waste metal, glass or cellulose production, presented in the form of small shavings or threads, which, when ingested, are intertwined, reinforcing (strengthening) the structure of the layer of finished plaster.