How to make a plaster solution correctly? How to make a solution for plastering walls? How to mix cement mortar for plaster

Plastering is the most basic and mandatory way to prepare walls for further finishing work. In the distant past, such work was carried out using the same technology and the same materials.

But now the construction market has changed so much and is so diverse that it is necessary to take a more careful approach to the selection of building materials and correctly observe the proportional relationship of all components.

The quality and lifespan of the entire finished surface depends on how correctly the solution for plastering walls is prepared.

Plaster is a kind of base, and the success of all subsequent work depends on the strength and quality of its composition.

Next, we will talk in more detail about how to prepare a solution for plaster, what proportions must be observed when preparing the composition, and what types of plaster solutions are used for interior work, so that subsequent processing is carried out easily.

Classification of types of solutions

There are 2 types of mortar for plastering walls: thin and greasy.

The composition of the lean mixture is characterized by a low content of binding components. Although it does not burst, it is not particularly strong.

Fatty mortar, on the contrary, is distinguished by a high content of binder, is easily covered with cracks and is susceptible to large shrinkage.

That is why pay special attention to what proportions of the binder component and sand are maintained in the mixture.

Here are the approximate proportions of how to prepare the most suitable solution for plaster:

1. Lime based mortar

To prepare such a composition, you need sand, the amount of which depends on the fat content of the lime. It should be mixed exactly on the day when the work is planned.

1. Clay mortar

Its preparation is similar to the previous type of solution, but to increase the strength it is customary to add lime, gypsum or cement to it.

1. A mixture of clay and lime

To prepare it, the following proportions are used: 1 part clay, 0.3 parts lime and ≈4.5 parts sand.

1. A mixture of lime and gypsum

This composition has a low level of hardening, so it is better to add alabaster, cement or gypsum to it and immediately use it for finishing work.

1. Gypsum-clay mortar

Here it is better to adhere to the following proportions: 1 part clay, 4 parts sand, part gypsum (the amount of sand is also affected by the fat content of the clay).

1. Cement-clay mixture

To prepare it, you need to mix 1 part clay with 0.2 cement and add sand from 3 to 5 parts.

1. Cement mortar

To work with such a solution, you need to take 1 part cement, 2 to 5 parts sand, 0.1 part lime. A similar composition sets after 35-40 minutes.

1. Cement-lime mixture

This mortar is mixed using the same technology as cement mortar, only milk of lime is mixed in instead of water.

As you can see, there are a lot of varieties of various plaster mixtures, so each of them is used for specific jobs.

For exterior finishing, cement with various admixtures is most often used, which is resistant to natural disasters and has a high level of strength.

If you need a composition for sealing cracks, it is better to choose gypsum-based plaster. It is white and almost invisible on light-colored surfaces, can be easily and evenly laid with your own hands, and can be covered with paint without any problems.

What are the features of the plaster solution?

Before you start mixing the solution, you need to sift all the components with your own hands through a construction sieve. If all proportions are observed correctly, the plaster mass should have a uniform consistency, fit well on the surface and not burst after drying.

As we have already said, plaster mixtures come in several types of fat content, which can be determined using a paddle when mixing the ingredients:

• if the mixture is mixed too oily, it will stick well to the mixer, and this can be corrected by adding fillers;
• if the proportions were maintained correctly and the mass does not stick very much, the fat content of such a solution is normal;
• if the mass does not linger on the mixer at all, we have a lean mixture to which we need to add additional binders or sand.

Why is a plasticizer needed?

A plasticizer is a substance that is added to building mixtures to give them elasticity. Plasticizers help increase fluidity levels without using excess liquid.

To prepare such a plaster solution, a plasticizer, filler and water are used. All these components are thoroughly kneaded until smooth.

A substance based on a plasticizer suitable for further work is considered to be a mixture that sticks with a thin film to the spatula with which it is kneaded.

Depending on the amount of plasticizer added, the plaster can harden and turn to stone in a few minutes or hours.

Plasticizers come in 2 states: liquid or powder. Both options are easy to use and can be diluted with plain water.

Each manufacturer indicates different proportions of the plasticizer, and they depend on the amount of other components that are included in the mixture. Its proportions, as a rule, are about 1%, that is, ≈1 kg of plasticizer is required per 100 kg of cement.

How to determine the concentration of plaster?

When you combine all the components in the required proportions and mix the plaster solution with your own hands, you will need to make sure that it has the correct consistency.

If the mixture is very thick, the walls may crack over time, but if, on the contrary, it is liquid, the walls will get dirty.

If the consistency is too thick, you can dilute it with water and achieve the required density with your own hands, and you can put dry brick into the liquid mass, which will absorb excess moisture.

Please note that all plaster mixture must be used in a timely manner, and only make a new batch if necessary. The mixture must be applied mechanically in an even layer or with your own hands using a medium-sized spatula.

When the plastering process is completed, the surface must be thoroughly dried and only after complete drying should grouting begin. Here it is important to guess the exact period of time so that the solution does not harden too much, but also no longer clings.

If one applied layer does not seem enough for you, you can repeat the coating, but wait 24 hours until the layer “rests”.

When the grouting is done, you can proceed to puttying the structures, which will give them the necessary smoothness.

Proportional ratios when mixing the solution

Preparing plaster for application to the wall

As mentioned earlier, the whole point of how to make a mortar for plaster with your own hands correctly lies in the proportions of the components. These ratios are shown in the tables below.

Composition of cement mortar

Cement brand	Cement/lime/sand ratio
	Produced brand of mixture
	150	100	75	30	25	10
400	1:0,2:3	1:0,4:4,5	1:0,5:5,5	1:0,9:8	—	—
	1:0:3	1:0:4,5	1:0:5,5	—	—	—
300	1:0,1:2,5	1:0,2:3,5	1:0,3:4	1:0,6:6	1:1:10	—
	1:0:2,5	1:0:3	1:0:4	1:0:6	1:1:9	—
200	—	—	1:0,1:2,5	1:0,3:4	1:0,8:7	1:0,8:7
	—	—	1:0,2:2,5	1:0:4	—	1:1:9

Composition of lime mortar

Composition of the gypsum mixture

Material	Plaster layer thickness (mm)
	15	20	25	30	35	40	50	60
Lime (l)	12	16	20	24	28	32	40	48
Gypsum (kg)	6,4	8,5	10,6	12,1	13	13,4	15	17
Water (l)	7	9	11	13	13	14	15	17

What factors influence material consumption?

Before you start plastering, you need to determine exactly how much mixture you will need to finish a certain area. Such knowledge will help you use building materials economically and avoid unnecessary waste.

Plaster is the basis before the final decoration of the walls. Today, there is a wide variety of materials from which you can prepare a solution for plastering walls. And here it’s worth choosing which composition is better to make with your own hands? In order to avoid unevenness and lumps in the preparation of mortar for the wall, you need to follow some rules and proportions, which will be presented in this article.

Solutions options

When preparing to level the walls with plaster, you should prepare a special solution, which should basically contain two main components: binder and filler. Each of them includes various materials that are freely available in markets and hardware stores. If one of the components is not used, the solution will either be weak, or will not stick to the wall, or it will be impossible to level it. And if the proportion is incorrect, you can initially make an even coating, but later, after complete drying, cracks will appear on the wall. The main types of plaster for leveling walls, which you can do yourself, are:

The first is a solution, which in most cases is used for plastering external, facade walls and plinths. That is, the presented type of plastering and its composition is mainly used in places of constant humidity. Inside an apartment or house, it is great for bathrooms and toilets. If you cook a lot and often enough, then it will also be a good choice for the kitchen.

The second type presented in the list is mostly used for external plastering of walls that are not exposed to moisture and humid air.

The third type is suitable for interior walls in all rooms, except those in which the air humidity level is quite high.

Quality of wall solutions

To get a smooth wall, you need to prepare the right plaster. To get rid of unnecessary lumps, it is recommended to sift all components through a construction sieve. If this is not done, then after cooking, you can find a heterogeneous mass, and you will have to strain the entire composition with your own hands, such work is not easy and takes a lot of time, so you should not go through this process. This process is one of the points of creating high-quality mortar for walls. Among other points it is worth highlighting:

Additionally, solutions for plastering walls are distributed according to fat content. You can meet with high fat content, with normal and so-called skinny ones.

Plastering process

The normal fat content of the plaster will ultimately lead to an ideal result, that is, the correct selection of all components and consistency. If there is increased fat content after drying, the process of cracking of the plastered wall surface will occur. Additional defects will include shrinkage and the appearance of cracks. In the presence of skinny, a process of lack of strength occurs, which leads to its falling off when leveled.

It is quite easy to determine whether the wall mortar has been prepared correctly, because all you need is a spatula. The difference is determined by the degree of adhesion of the plaster to the spatula:

Characteristics and composition

Now we choose which composition is suitable for specific purposes.

Lime. Lime dough and sand are used, composition ratio 1:3. The dry mixture is mixed with water. With the right consistency, the end result should be like a thick dough.

Lime-cement. To give greater strength, you need to add a tenth of cement and mix. All lime-based solutions must be prepared and used within 2 days.

Lime-gypsum. The composition ratio is 5:1, add water and mix. It is necessary to take into account the fact of rapid drying - in half an hour you won't be able to work with it. But if everything is done correctly, the plaster on the wall will be super durable.

Lime-clay. The ratio is 1:1, an additional fifth of sand is added. Also has high strength.

Clay. First you need to prepare dough from clay. This is done by adding water. When receiving clay dough, it is mixed with sawdust in a ratio of 1:3. Adding water and stirring is present in every solution. It has disadvantages in the form of fragility and instability to moisture.

Clay-gypsum. The proportion and subsequent actions are identical to the lime-gypsum composition. Only here the basis is clay dough.

Cement. Used to treat walls that are constantly exposed to moisture or steam, regardless of external or internal use. The proportion is either 1:3 or 1:4 with sand. The property of quick drying allows you to work with it only for 1 hour.

Cement-lime. To prepare it correctly, you should carefully monitor the balance of the composition. Materials used:

You can prepare such plaster for walls with your own hands in two ways:

Modern materials

Today, people have begun to give preference to special dry mixes that are produced on the basis of Portland cement and are considered to be of high quality. In addition to the direct base, they also have special additives that provide the solution with additional characteristics in the form of increased strength and ductility. There are a number of advantages that come with such a dry mixture, which is not difficult to make. Among them are:

• Easy application to the wall without the use of reinforced mesh, which significantly reduces material consumption.
• greater elasticity. After drying, it tolerates temperature differences and rapid climate change very well.
• allows air to pass through itself and has a fairly strong resistance to moisture.

There are also modified wall mixtures that were prepared separately in laboratories. This process was carried out to ensure that the ratios of all components were perfectly observed, which ultimately led to a perfectly prepared solution. As an addition, it can be noted that plaster can be produced in different volumes, that is, as much as is required at the moment without excesses, residues or shortages. Sometimes they even write on the packaging the words “pour water and get started.”

Now you know the basics, all that remains is to choose high-quality materials for preparing a plaster solution for walls with your own hands and enjoy the work. Watch the video to reinforce:

Plastering walls and ceilings is an important stage of finishing work. The facing coating performs the functions of protection, decoration and additional insulation, perfectly hides seam joints and corrects minor defects in masonry. Strength and durability depend on the correct ratio of the components of the solution.

The basic composition of any plaster always remains the same: binder, filler and water. The choice of binder depends on the nature of the finishing work (external/internal) and operating conditions (wet/dry microclimate). It can be cement, clay, lime, gypsum. Quarry or river sand is most often used as a filler. Sawdust, perlite, fine slag, and granulated polystyrene are less common. The filler ensures the strength and smoothness of the layer.

In practice, cement mortars are most often chosen for finishing external and internal walls; they are characterized by increased strength and durability. The technological feature is slow (about 12 hours) setting. To change the quality characteristics, it is combined with other binders. The proportions of the main elements in the composition of the plaster determine its performance indicators.

• Pour in pre-sifted dry sand. To clear it of pebbles and shells, you need to use a sieve with small cells. For priming walls, a diameter of 2-3 mm is suitable, for finishing – no more than 1 mm.
• Add cement and mix everything thoroughly. It is very important that the sand is well dried, then it combines evenly with the cement, does not burden it and prevents the formation of lumps.
• Pour in water. First add no more than 2/3 of the total volume. Add the rest gradually, achieving homogeneity of the mass.

The prepared solution must be used within an hour. Left unspent, it begins to harden. If you add more water, you can restore elasticity, but the quality will be worse.

2. Cement-lime plaster.

Can be prepared in two ways:

• Mix lime paste with sand and add cement to it. Stirring constantly, add water little by little to the desired consistency.
• Cement and dry sand. Prepare lime milk by combining water with lime dough in a 1:1 ratio. Dilute the sand-cement mixture with milk.

3. Cement-clay.

• Wet the lumps of clay with water and cover them with a thick rag.
• Mix the swollen clay with sawdust in a ratio of 1:3.
• Adding water little by little, bring to the required density.
• To enhance the strength, add dry cement to the composition and mix thoroughly.

Solution consumption

The smaller the building elements, the more joints there are in the masonry. This directly affects the unevenness of the walls. Deviations from the level can be both vertical and horizontal. Leveling highly curved surfaces will require a lot of compound. To calculate its consumption per 1 square meter, you need to multiply the thickness of the layer and the area of ​​the walls.

To obtain curvature data, it is convenient to use a beacon. In this case, the minimum thickness of the plaster will be 6 mm. This slightly increases consumption, but all surfaces reach an ideal level.

To find out the maximum value of curvature, it is necessary to hang the walls in several places. The more measurements, the more accurate the calculations will be. For example, deviations of 10, 15 and 40 mm were found. These parameters need to be added up and the sum divided by the number of measurements: (10+15+40)/3=22 mm. The result is an average thickness of the plaster. Now all that remains is to multiply it by the area of ​​the working surface.

For those developers who prefer to use ready-made mortar in dry form, it is easier to make calculations. On the back of the packaging, manufacturers themselves indicate the exact material consumption. With a layer thickness of 10 mm, approximately 10 kg of mixture per square wall is required.

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 the plaster solution is selected and prepared for use indoors or outdoors.

It probably doesn’t seem new and everyone has long known that modern plaster mortars using new technologies are made from dry building mixtures, which are mixed with the amount of water specified by the manufacturer, l/1 kg of dry mixture.

Yes, such mixtures are popular, since they can be used to get the job done quickly and efficiently, but plastering a house with such compositions is not a cheap undertaking. The fact is that in terms of price, they are several times, or even tens of times, more expensive than traditional compositions due to the presence of all kinds of modifiers, plasticizers and high-quality, selected fillers.

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 solutions, or rather the composition of a solution for plastering work, which contains a list of components:

• astringent;
• filler;
• modifying additives.

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

Among the factors influencing the selection of components for the plaster mortar are the type of surface, the purpose of the room and the amount of money for plaster, in the end.

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

The binder for a plaster mortar is a component on which almost everything depends: strength, water resistance, setting speed and, partly, plasticity.

For example, the composition of a cement-based plaster mortar has the highest degree of strength and water resistance compared to lime mortar, which, unlike the first, is used only for plastering walls inside residential premises. But lime mortar is more plastic and therefore easier to work with.

There are also solutions that contain two binders, for example cement-lime or lime-gypsum mortars, which are called complex mortars. To clarify, let’s make a list of binder components that are included in the plaster solution:

• cement;
• lime;
• gypsum.

In this case, the list of binders is small; these are all its types, which are used in the preparation of modern dry construction mixtures for plaster mortars, and in the preparation of traditional compositions, the proportions of which we will consider below for each individual binder.

Cement binder considered the most durable and waterproof.

It is used in the production of cement-sand and cement-lime plaster mortars, which are used for finishing walls inside and outside.

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

It is important what brand of cement is used, for example, if you take cement of the M400 brand, then for 1 such bag you will need four bags of sand for plaster mortars (or other appropriate fine-grained filler) in order for the mortar grade to be M100.

Cement brand	The ratio of cement: lime: sand and the grade of mortar produced

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

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

Lime prevents the development of microorganisms even decades after application.

Lime-based solutions are plastic, adhere well to the wall and are easy to level, and can also be grouted.

There are two main types of it - hydraulic and air. Hydraulic lime is less plastic, therefore, it is more difficult to work with such a solution, but it is stronger after setting, and it sets faster than air lime.

As for the proportion of the plaster solution, it depends on the type of lime (there are only three), as well as its condition (ground boiling water or lime paste). Today, ready-packed lime dough is mostly used for the production of lime, lime-gypsum and cement-lime mortars for plaster.

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

has the best plasticity and differs from the previous ones in its almost lightning fast setting speed.

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

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

Material	Plaster thickness, cm
Lime mortar, l

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

Types of fillers included in the mortar for plaster

The filler for the plaster mortar determines its qualities such 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, it is sand; for special plaster, the range of fillers is much wider; for decorative plaster, ground types of semi-precious stones are used. In addition, they may contain impurities; The grains themselves can be of different shapes and have different densities and much more. Let's look at the types of fillers for plaster mortars, 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 plaster mortars are prepared in advance, sifted in production or directly at the construction site, where the work on preparing the plaster mixture takes place. Let's take a closer look at each of the data in the list of fillers.

Sand for ordinary plasters is a fine-grained stone material that, with the help of a binding material, forms a solid artificial stone with similar properties.

For the plaster mortar, take gully or quarry sand with a fraction of up to 5 mm, which contains a minimal admixture of clay or no clay at all; The grains themselves have a sharp shape, which provides better dressing.

However, there are cases when gully sand is not acceptable - when plastering facades, when the absence of clay impurities is required. At the same time, the composition of the solution for facade plaster contains a filler - river sand, and modern additives are used to improve plasticity. Plaster with such a filler does not have any special qualities, neither decorative nor special.

Sand for special plasters has special properties. Thus, serpenite and barite 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 and diabase flour are fillers for acid-resistant plasters. Metal shavings and dust are used as fillers for impact-resistant plaster.

There are also fillers that have a high thermal insulation effect, such as perlite sand, which is part of the solution for thermal insulation plaster.

Sand for decorative plasters can be very different. This can be a mineral filler of a fraction of 1.5-4 mm for modern so-called “facade” decorative plasters.

There is a finer filler than sand - granite and marble flour, as well as other ground decorative and semi-precious stones.

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

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

These substances act like an astringent component, enhancing its effect and, accordingly, increasing the grade of the solution.

They can be of natural origin (sedimentary and volcanic) and artificial. Natural sedimentary rocks are diatomites, tripoli, opoka, gliezhi; natural volcanic - trails, tuffs, ash, pumice; artificial - siliceous waste, burnt clay, fuel waste.

Types of modifying additives included in the mortar for plaster

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

Their method of action mainly comes down to interaction with the binder (cement) and the enhancement of certain of its properties.

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

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

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

Set accelerators/retarders - these are substances that, through 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 a gypsum mortar for plaster depends on the presence of a set retarder; in this case, bone or casein glue acts as a classic retarder.

It is clear that today these additives are presented as complex chemical substances that have complex mechanisms of action on the binder, allowing them to achieve the desired result.

Additives to improve frost resistance existed before and still exist.

Along with ferric chloride, the overwhelming majority of the market offers modern, harmless additives based on special salts. These additives dissolve in water, which is used to mix the dry mixture of binder with filler.

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

Additives to improve plasticity very desirable for use in plaster mortars made using traditional technologies.

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

The essence of such additives is to retain most of the water in the solution and prevent it from separating. Getting into the water and shaking with all the components of the solution, this additive creates many small bubbles in which the water is retained for some time.

Strength Additives /brands of mortar can act both in interaction with the 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 individual additives that are not chemically active (do not participate in the formation of the crystalline network), but are used as a durable filler (reinforcing additives).

This is the so-called waste from metal, glass or cellulose production, presented in the form of small shavings or threads, which, when added to the mixture, intertwine with each other, reinforcing (strengthening) the structure of the finished plaster layer.

Plaster is a rough finishing of walls and ceilings, as well as the facade of a building. After its application, all other work begins. You can do it yourself or invite specialists to do it.

This stage of repair is important because plastering provides protection to the surfaces. You especially shouldn’t hesitate to finish the façade, as it is more vulnerable to external influences.

Despite the labor-intensive work and the long drying time of the coating, plastering is a classic method of finishing premises.

Peculiarities

With the help of plaster, you can implement a variety of design solutions and create surfaces that imitate various textures and materials. It is suitable for all types of surfaces - from brick to wood.

For interior work, plaster is divided into:

• structural – characterized by heterogeneity and gives relief;
• textured - characterized by the graininess of the materials, giving a different texture, for example, like stone, wood or sand;
• decorative – gives the effect of painting, improves the appearance of the surface;
• stone - creates an original design;
• latex artificial plaster – resistant to mechanical damage.

Exterior plaster can also create an attractive appearance for a building, but its main function is to strengthen the walls and protect them from destruction. Most often it is applied in several layers.

The features of this type of finishing also include increased thermal insulation and noise insulation, imparting evenness and eliminating surface defects, water and fire resistance of the surface.

Most often, cement and gypsum mortars are used for plastering. They are characterized by relatively low cost and quick drying.

To facilitate the work, you can use special plastering stations, since plastering is a rather complex process that requires effort. This saves not only time, but also materials. The plastering station allows you to process a large area at a time, which does not require further processing.

Primary requirements

Due to the fact that plaster is the basis for subsequent work, many requirements are placed on it. The quality of the solution is determined by its strength, plasticity, good adhesion and optimal density.

It is necessary to pay attention to the composition and proportions of materials. The scope of application of plaster solutions and their functions depends on this. Also important indicators are water resistance and fire resistance.

The strength and durability of the coating is affected not only by the composition of the solution, but also by the quality of surface preparation. Protrusions and holes on concrete surfaces are sealed and cleaned with special brushes. If necessary, lay a metal mesh, and before applying the plaster, the surface is slightly moistened with water.

Brick walls also need to be cleaned and leveled. Before finishing metal surfaces, you must ensure that there is no rust. It is recommended to finish wooden surfaces with shingles or special panels. Shingles are thin wooden boards made in the form of a grid.

Types of mixtures

There are basic types of solutions and combined ones.

The main ones include:

• cement (the most durable);
• clay (reusable);
• limestone (increase plasticity and adhesion);
• gypsum (quick drying).

Almost always, to prepare solutions, river sand is added to the base material, which has a positive effect on the strength of the finished composition and does not require purification.

Combined solutions consist of several basic materials and thereby improve the properties of the plaster.

Cement plaster is heavy, making it a little difficult to work with. Despite this drawback, the cement mixture provides long service life, strength and water resistance. Cement plaster consists of natural materials, therefore it is considered safe and environmentally friendly.

The long drying time of the material is both an advantage and a disadvantage. In the first case, it is possible to immediately prepare a large amount of mortar, but in the second, it becomes necessary to wait a long time for the plaster to completely dry (approximately 10-14 days) before carrying out subsequent work.

It is important to monitor the amount of sand added to the solution, as it may reduce the adhesion ability of the mixture.

Cement-lime plaster is used if it is necessary to obtain a more durable composition. However, the main thing is not to overdo it, since a large amount of lime will have the opposite effect - the plaster may become covered with cracks. The ideal ratio of lime to cement mixture is 1:3.

Cement-lime mortar is used for interior finishing of the building and for facade finishing.

Lime-gypsum plaster is used for finishing rooms with average humidity (not suitable for a bathroom) with walls made of stone, wood and other materials.

It is important to take into account the fact that gypsum hardens very quickly.(approximately 10-15 minutes), so the solution is prepared in small portions. You should not dilute the solution into hardened plaster - this, on the contrary, will lead to a loss of strength and adhesion. It is also advisable to divide the surfaces into small sections and plaster them one by one.

Clay plaster is the oldest finishing material. Working with it can take a long time because the clay must first be prepared. This type of plaster is used for rooms with very low humidity. Lime (for greater plasticity), cement (for increased strength) or gypsum (for faster drying) are often added to the clay mixture.

The main distinguishing feature of clay plaster from other types is the ability to be diluted with water when completely hardened. Thus, if too much solution has been prepared and it has hardened, then water can be added to it again and used for finishing surfaces. At the same time, the quality of work will not suffer.

Gypsum plaster, with such advantages as light weight, ease of application and high strength, has one drawback - the lack of water resistance. For a short hardening time, you can change the recipe of the gypsum mortar by adding tile or PVA glue to it.

Decorative (terrasite) plaster is mainly used to decorate facades, sometimes for corridors. The possible composition of such plaster is very extensive, but cement and color pigments are almost always used. To obtain various imitations, special additives and the use of the necessary finishing tools are required.

Terrasite plaster is distinguished by the level of granularity, which depends on the filler fraction:

• fine-grained – fraction up to 2 mm;
• medium-grained – 2-4 mm;
• coarse-grained – 4-6 mm.

Any plaster includes filler, water and a binder.

The proportions of these elements in the solution also depend on the type of work:

• spray;
• primer layer;
• finishing layer.

The least amount of binder is used for spraying, and more for the finishing layer. This is the reason for the high strength of the finishing material.

Plastering can be carried out in all three layers, as well as in only one. For each method, individual proportions are selected. Compositions that contain clay always contain less of this material.

If you want to improve certain properties of the plaster, you can purchase special additives. For example, plasticizers increase the plasticity of the mixture and provide an even coating and prevent delamination. They can also reduce the amount of water required.

In the cold season, additives with antifreeze properties will help to carry out finishing work by preventing the solution from freezing. Quartz sand increases resistance to acids, mica protects against ultraviolet radiation. Metal shavings are rarely used due to their corrosive properties, but they enhance the strength of the coating.

If it is necessary to increase adhesion or reduce curing time, then you can easily find the appropriate additive.

There is also a wide range of decorative additives:

• marble chips are used to create a Venetian style;
• flocks (colored pieces of acrylic) give the effect of a suede coating;
• wax and resin additives are used to imitate stone and silk.

The main rule when using additives is their amount, which in the solution should not exceed 10% of the main volume. Some additives can be added to the solution using a syringe.

The difference between plaster and ordinary putty is that putty is a finishing touch and hides defects that were made during plastering.

How to cook?

To prepare the plaster solution, you need to use the following tools:

• container for materials;
• concrete mixer (can be replaced with a mixer or shovel);
• binder, aggregate and water;
• dispenser

To prepare cement plaster, you first need to sift the sand and clear it of debris and lumps. Then thoroughly mix the dry cement and sand. To do this, use a concrete mixer or mixer. Once the elements become a homogeneous mass, you can gradually add water, gently continuing to stir. The finished composition should acquire the state of thick sour cream.

Based on fat content, mixtures are divided into:

• fatty (has strong stickiness);
• normal;
• skinny (no stickiness).

A high-quality mixture should have a homogeneous composition and normal fat content.

To prepare a clay solution, you need to soak the alumina in water for several hours, and then knead it so that there are no lumps. After this, add sawdust to the clay. The alumina should ultimately be quite thick. To achieve this result, you need to constantly stir the mixture and add a little water.

To completely get rid of lumps and debris, you can wipe the solution using a sieve. After these steps, sifted sand is added. But such a mixture will not have sufficient strength, so cement, lime or gypsum are also added to it.

To prepare lime-based plaster, you must use only the slaked substance. First, this material is mixed with water, and then sand is gradually added.

You can tell when the plaster has dried by its color changing from grayish to white. The finished mixture can be stored in a container for about three days, but it is not recommended to delay its application, because over time the solution begins to lose its plasticity.

If the lime is quicklime, then it is necessary to slak it. To do this, dry lime is diluted with cold water. It is important to use a large capacity container, since quenching is a violent reaction. Safety glasses and clothing may be required. Lime in this state should last for about two weeks.

To create a lime-gypsum solution, add gypsum to water and mix until smooth. Then lime is added. It is advisable to perform all preparation steps quickly, since the plaster dries quickly.

Cement-lime plaster can be prepared with your own hands in two ways:

• Cement and sand are mixed dry, then you can dilute them with milk of lime, purified using a sieve. All elements are thoroughly mixed.
• First, lime, sand and water are mixed, and only then cement is added. The resulting mass is also mixed.

Decorative plaster can be made from any binding materials, but with the obligatory addition of decorative additives and color pigment.

The recipes for preparing solutions are not very different, but the characteristics of the materials used are taken into account.

To prepare the solution yourself, you must follow these steps:

• all dry materials for plastering must first be sifted and completely cleaned;
• to be sure of the homogeneity of the resulting composition, it is advisable to strain it;
• the proportions of materials in the composition are regulated by the type of work (spraying, priming or finishing).

Currently, you can purchase ready-made dry mixtures that only need to be diluted with water. They are good because they have a professional and specialized composition and contain various additives to enhance strength and ductility.

Possible mistakes

The quality of the final plaster depends on the correct preparation of the composition and compliance with the proportions of materials. Errors can result in cracks on the surface, peeling, and swelling.

Poor mixing of the solution leads to cracks due to the high concentration of binder or aggregate in one area. Cracks also appear from exposure to too low or high temperatures or drafts. Therefore, after applying the plaster, it is best to close all windows and doors.

A new layer can be applied only after the previous one has completely dried.

There is a misconception that if you add more cement, the strength of the mortar will increase. But this is not true. Of course, the solution will become denser, but when it dries, cracks will quickly form on the surface.

Before applying the plaster, you must ensure that the surface is completely dry. Otherwise, the coating will not adhere well and will quickly peel off. But an overdried surface will not retain the coating. It is also not recommended to make layers that are too thin or thick.

For better fixation of the plaster mixture, you should make sure that the surface is sufficiently rough. If you apply layers of different thicknesses, then after drying this will be noticeable by the uneven color of the surface due to different drying times.

The strength is affected by the amount of binder and the absence of contamination in the materials. Gypsum plaster cannot be used on concrete surfaces; this can lead to destruction of the surface. It is also not recommended to apply lime mixture to plaster.

Before plastering the brick, it is better to moisten the surface, since this material has good moisture absorption. Before finishing work, it is necessary to completely clean the surface of any contaminants so that the solution exhibits better adhesion. Do not forget about preparing for plastering the facade - if there are reinforced concrete beams, they are covered with clay baked in a kiln.

It is not advisable to use gypsum plaster for exterior finishing, since it becomes deformed when exposed to rain or snow. To obtain a perfectly even coating, beacons can be installed on the surface. To do this, you first need to check the verticality of the wall, and then drive the dowels in the right places and stretch the fishing line along them. To avoid a break, it is necessary to tighten the fishing line between the outer beacons.

To correct uneven corners, apply an additional layer of plaster. If the unevenness is too large, then first completely knock down the layer of plaster and reapply it.

It is best to carry out plastering in spring or autumn, when there is no hot sun or severe frost. You can cover surfaces from the sun with a special protective canopy.

A thick layer of mortar may crack, but if it is necessary, then it is necessary to stretch a metal reinforcing mesh before applying it. It is advisable to carry out all installation work before plastering, so as not to damage the coating or pipes (wires). Communication elements are placed in special recesses in the wall and covered with plaster. Heating pipes should not be left close to the plaster, as when heated they expand and the coating is destroyed; rust spots may also appear due to the ability of gypsum to absorb moisture.