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 inside or outside the premises.

Probably, it does not seem new and everyone has long known that modern plaster solutions using new technologies are made from dry building mixes, which are mixed with the amount of water specified by the manufacturer, l / 1 kg of dry mix.

Yes, such mixtures are popular, because with the help of them you can quickly and efficiently do the job, but plastering a house with such compositions is not a cheap undertaking. The fact is that at a 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 in them.

So if the construction budget is small, then it may make sense to use good old cement or lime plasters. Therefore, in this article we will consider traditional solutions, 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 can 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, there are also the type of surface, the purpose of the room and the amount of funds for the plaster, in the end.

Types of binders that make up the mortar for plaster, the proportions of the mortar for plaster

A binder for a plaster 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 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 the lime mortar is more plastic, therefore, easy to work with.

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

• cement;
• lime;
• gypsum.

In this case, the list of binders is small, these are all of its types that are used in the preparation of both modern dry building mixes 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 water resistant.

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

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 of them, including fast-hardening ones.

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

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

If we take the M500 brand, then it will have five parts of the corresponding filler for the M100 mortar brand. The corresponding proportion is also observed in the manufacture of cement-lime mortars.

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

Lime prevents the development of microorganisms even decades after application.

Lime-based mortars are plastic, stick well to the wall and are easily leveled, and also amenable to grouting.

There are two main varieties - hydraulic and air. Hydraulic lime is less plastic, therefore, it is harder 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 mortar for plaster, it depends on the type of lime (there are only three of them), as well as its condition (ground boiling water or lime paste). Today, ready-made packaged lime dough is used to a greater extent for the manufacture of lime, lime-gypsum and cement-lime mortars for plaster.

Even more often you can find ready-made lime mortars packed 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 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, it is a brand of gypsum G-2, G-3, G-4, G-5 with fine, medium or coarse grinding (grain size), which is called building gypsum.

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

Material	Plaster thickness, cm
Lime mortar, l

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

Types of fillers included in the mortar for plaster

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

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 a special one, the range of fillers is much wider, for decorative, ground rocks of semiprecious stones are used. In addition, they may contain impurities; the grains themselves can be of various shapes and have different densities and much more. Consider 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, sieved at the factory or directly at the construction site, where the preparation of the plaster 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, forms a solid artificial rock with similar properties.

For plaster mortar, ravine or quarry sand is taken 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 ravine sand is unacceptable - 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 mortar for thermal insulation plaster.

Sand for decorative plasters is the most varied. It can be a mineral filler with 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 semi-precious stones.

The composition of the 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, 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 during the setting of the solution.

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

They can be of natural origin (sedimentary and volcanic) and artificial. Natural sedimentary ones are diatomites, tripoli, flasks, gliezhs; natural volcanic - trails, tuffs, ash, pumice; artificial - silica 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 qualities. There are universal and narrowly targeted modifiers.

The mode of their action is mainly reduced to the interaction with the binder (cement) and the strengthening of certain 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, respectively, improve the strength of the plaster itself. Regarding their functions in the solution, modifiers for plasters are divided into the following varieties:

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

This list contains additives of both the old and the new sample. They can be presented in the form of bulk or liquid materials that are pre-mixed with water, or they can be poured directly into a container when preparing a plaster composition. Next, we will 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 crystal network (the ability to set).

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

It is clear that today these additives are presented as complex chemicals with complex mechanisms of action on the binder to achieve the desired result.

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

Along with ferric chloride, the majority of modern, harmless additives based on special salts can be found on the market. These additives are dissolved in water, which is mixed with a dry mixture of binder and filler.

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

Additives to improve ductility highly desirable for use in plaster mortars made using traditional technologies.

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

The essence of such additives is to keep 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 many small bubbles in which water is retained for some time.

Strength Additives /marks of the solution 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 separate additives that are not chemically active (do not participate in the formation of a crystal network), but are used as a durable filler (reinforcing additives).

This is the so-called waste of metal, glass or cellulose production, presented in the form of small chips or threads, which, when they enter the mixture, are intertwined with each other, reinforcing (strengthening) the structure of the finished plaster layer.

Plastering walls is no easy task. The quality of the finishing of the walls directly depends on it. If you decide to do this work with your own hands, then we will tell you how to prepare a mortar for plaster, the proportions in which must be strictly observed. Otherwise, you can get not a smooth, even and durable surface, but a loose, porous layer of mortar, ready to fall off at any moment.

In the article we will answer questions about the composition and proportions of the mixture based on various components, we will talk about the requirements for mortars for plaster, as well as about the types of various modifying additives.

Buy ready mix or make your own

In this matter, the main role is played by the finishing area, as well as the physical and financial capabilities of the owners.

• Ready plaster mix.

The composition, in addition to the main selected and high-quality components (cement, sand), includes many special additives - modifiers, plasticizers that improve the working and operational qualities of the plaster.

But the price of such a mixture is much higher than that of a do-it-yourself solution. Therefore, it is unprofitable to use ready-made plaster on a large area. But if you need to finish a small surface, then it is better to purchase a ready-made composition. You don’t have to buy all the components separately, charge the mortar mixer, and it will take less time.

• Do-it-yourself plaster mixture.

When you have to finish a large brick or foam block house, then to reduce the cost of work, the owners usually prefer to prepare the plaster mixture on their own. Cement, sand are bought, a small mortar mixer is installed, and little by little, in portions, a solution is prepared.

In this case, you have to work with your hands and spend some amount of personal time. But as they say, "your work does not count."

When working independently, it is necessary to strictly observe the proportions of the mortar for wall plastering, otherwise there is a risk of reworking all the work already at the application stage. Even worse, if a low-quality solution begins to fall off at the stage of finishing, fine finishing.

It is possible to correct such a marriage only with the complete removal of the applied plaster and replacing it with a new layer. And this, as you know, additional and considerable expenses.

Types of cement mortar, requirements, proportions

There are few types of mixtures, but each requires separate consideration, as it has its own unique characteristics. They differ in the presence of various additional components in the solution.

So, the plaster mixture can be:

Used for leveling and finishing. Such a mixture is compatible with any rough surfaces, except for concrete, due to weak adhesion to the latter.

This mixture is mainly used for rough plaster; for finishing, sand of a very fine fraction is needed. The mixture remains "alive" for an hour, after which the technical parameters deteriorate.

• Lime-cement.

Used for finishing brick or concrete surfaces. Lime gives the solution plasticity, which facilitates its application and stretching. It also increases the vapor permeability and strength of the solution, extends the "survivability" of the mixture up to 3 hours.

In addition, lime has bactericidal properties, on walls covered with lime mortar, mold will never form, fungus and microorganisms will not appear. But the proportions of lime mortar for plaster must be observed in order to avoid lime stains on the walls.

Lime "efflorescence" will bring a lot of trouble when finishing, since not all paints or putties are compatible with this material.

• Gypsum-cement.

It is applied to the improved plaster of walls. Gives an even, durable layer that can be easily sanded. It sets quickly, so it is not recommended to prepare a large amount of solution at once.

If it is necessary to prepare a lot of mortar, then setting retarders are used to extend the "life" of the plaster mixture. They are already present in ready-made mixtures.

Important! In mixtures prepared independently, depending on the air temperature, the type and quality of the surface, the type of room, it is necessary to add special components. Properly selected mineral fillers, polymeric additives or plasticizers will make the solution more plastic, frost- or heat-resistant, enhance adhesive and astringent properties.

Cement-sand and lime mortars are used for interior or exterior walls (see How exterior walls are plastered) exposed to moisture, gypsum-cement mixtures are used only for interior work in dry rooms.

Requirements for the components of the solution

The composition of any plaster solution includes three main components: cement, sand and water. The strength and durability of the applied layer, as well as the quality of grinding and subsequent finishing, directly depend on their quality.

So:

1. Cement.

• This is a binder component that plays a major role in the formation and hardening of the solution, giving the mixture strength and water resistance.
• The proportions for the preparation of the plaster mortar are standard. it is recommended to use Portland cement or Portland slag cement at least M300.
• It depends on the brand what proportions of cement and sand for plastering will need to be taken: the higher the brand, the more parts of sand need to be added per unit of cement.
• This material also has a shelf life, the fresher the cement, the better the performance. It is advisable to purchase it in paper bags and store it in a dry place.

Cement is not afraid of frost, but from high humidity, the hardening process can begin right in the package.

1. Sand.

This material is the filler of the plaster mixture, it determines the strength, weight, thermal conductivity and density of the solution.

• When interacting with cement, sand creates a monolithic layer with the properties of solid rock.
• For rough plaster, fine-grained ravine sand is taken, in which a small presence of clay is allowed.
• If there is a lot of impurities, then the solution is able to settle and delaminate. It will have to be constantly mixed, and it is still difficult to work with it, as the ability of the mixture to stick and level is reduced.

For an improved layer, river sand is best - or ordinary, but clean, sifted through a fine sieve, washed from impurities. And again, we must not forget about the proportions - cement-lime plaster will turn out to be of higher quality if the sand in it does not contain clay impurities, and the amount of filler does not exceed the required volume.

1. Water.

• The liquid for the solution must be clean, free of oil impurities, various organic and chemical contaminants, debris.
• All impurities after evaporation of the liquid will remain in solution and can significantly affect the quality of further finishing.
• Oil stains will show through the plaster or wallpaper, the paint will peel off in this place. The same can happen from the presence of chemical impurities. Therefore, experts recommend using clean, better drinking water.
• When mixing with water, the cement setting process begins in the plaster mixture, therefore, after kneading, the solution must be worked out within 1 hour.

Longer storage of the mixture reduces the technical characteristics of the material, and complicates the work.

Proportions of components for different types of solution

Any instruction requires strictly observing the proportions of cement and sand for wall plastering, so that the work is quick and pleasant, and the result is pleasing with strength and reliability.

If there are no plasticizing additives, then to improve the plastic properties of the solution, the masters advise adding a little neutral liquid soap or soap solution:

• In the cement-sand mixture, the composition of the main components should be as follows:

Grade of cement	Cement/sand, parts	Produced brand of mortar
M300	1/3,5	M100
	1/2,5	M150
M400	1/4,5	M100
	1/3	M150
M500	1/5,5	M100
	1/4	M150

Water is added to the mixture gradually, with constant stirring. The solution is brought to the consistency of thick sour cream.

Important! Too plastic mortar will lie unevenly on the wall, drain, and when leveled, it will reach for the tool. A hard mixture will stick to the trowel, making it difficult to throw it on, and when it dries, it will shrink and crack. You can recognize a normal solution by immersing a trowel, the mixture should leave a thin layer on it without adhering lumps.

• Lime mortar for plaster, proportions:

Grade of cement	Cement/lime/sand, parts	Produced brand of mortar
	1/0,3/4	M75
	1/0,2/3,5	M100
	1/0,1/2,5	M150
	1/0,5/5,5	M75
	1/0,4/4,5	M100
	1/0,2/3	M150
	1/0,8/7	M75
	1/0,5/5,5	M100
	1/0,3/4	M150

When cement-lime plaster is used in the decoration, the proportions of lime in the composition of the solution are small, so it is better to purchase ready-made lime paste at a hardware store. It is rather problematic to prepare the necessary component with your own hands, the term for slaking and aging lime is about a month using a special technology.

An improperly prepared or unripened mass can destroy the plaster mortar and nullify all work.

Modifying additives

Separately, it is necessary to talk about additives in the plaster mortar, with them the mixture will acquire some important properties necessary both for applying and treating surfaces, and for their further operation.

Here, too, it is important to maintain the proportions for wall plaster: each package contains detailed instructions for using the additive, and it must be strictly followed:

• Setting accelerators or retarders.

These are components that act on the crystal lattice of the binder and regulate the time of its formation (setting).

It is desirable to make them, for example, in a gypsum-cement mixture to extend its "survivability". In this case, casein or bone glue serves as such an additive.

• Additives to increase plasticity.

These substances, getting into the solution with water, form a lot of bubbles, due to which the liquid evaporates less and is absorbed into the surface, which means it stays in the mixture much longer. They are recommended for simple, traditional cement-sand mortars that quickly lose water and delaminate.

• Antifreeze additives.

Basically, it includes various special salts that slow down and even exclude for some time the freezing of water in the solution, which means that they reduce the risk of losing the positive qualities of the mixture when the air temperature drops.

I must say that they operate mainly up to -5 degrees. At a lower temperature, plastering work cannot be carried out, here no additives will save the mixture from freezing.

• Strength additives.

They can be of two types: some work in tandem with a binder, by means of chemical action they increase its properties; others act independently, personally perform a reinforcing function.

The second type is called fiber, which may consist of waste glass, pulp or metal production. Fiber is sold in the form of small chips or polymer threads, which, getting into the solution, intertwine and give the plaster additional strength.

Conclusion

If the surface of the walls turned out to be not too smooth, do not be upset - all the small irregularities will be hidden by the finishing putty. The main thing is that the plaster itself is strong, does not crumble, does not crack and does not fall off.

By correctly determining the composition and calculating the proportions of the plaster, you will get a high-quality and durable coating that will not require repairs for many years. And after looking at the photos and videos in this article, you will get answers to other questions that concern you.

But if you are still not confident in your abilities, and do not risk plastering the walls yourself, then we recommend inviting specialists who will do this work quickly, beautifully and efficiently.

When carrying out measures for the repair and improvement of the home, one of the most important operations is the application of the plaster composition, as well as the elimination of irregularities on the surface of the walls. The plaster mixture can be purchased at the store or prepared independently from various ingredients. Giving preference to the second option, figure out how to prepare a solution for plastering walls. You need to know which components to use, as well as in what proportions to mix them. We will deal with the recipe options and cooking technology.

Wall plaster mortar

What composition of the solution for interior wall plaster to choose

When deciding which solution for plastering surfaces it is preferable to use, we will evaluate the features of the ingredients used for binding, and also consider the types of plaster compositions.

Varieties of binders and aggregates

Used as a binder:

Along with binders, various fillers are used.:

• sand;
• sawdust;
• slags;
• shavings.

The most common is quartz sand mined in rivers. The technology provides for washing, due to which salts and clay particles are removed. River sand is superior in quality to similar material mined in quarries. Screened fine, medium and coarse sand is used, the particle size of which ranges from 0.2 to 4 mm.

Types of compositions for plastering

Proportions of mortar for wall plaster

When choosing a composition for plastering, it is necessary to take into account a number of factors:

• the binder used;
• surface material;
• temperature conditions;
• humidity level.

When choosing the best option for plastering material, pay attention to the following points:

• plasters containing building lime and cement are used for facade decoration, when it is necessary to provide protection from the negative effects of high humidity. If high humidity is expected in the interior, such a composition is also used for interior decoration;
• the introduction of clay, slaked lime and gypsum into the plaster composition allows it to be used at an increased concentration of moisture in the air. Such mixtures are mainly used for plastering dry heated and unheated premises located inside the building;
• cement-gypsum plaster composition, to which clay is added, is used for interior decoration of premises with a normal moisture concentration. It is possible to use these binders when plastering the facade surfaces of buildings operated in a dry climate.

How to prepare a mortar for plaster

Preparation of mortar for plaster

The technology for preparing each type of plaster mortar has its own characteristics. Let us consider in more detail the recipe and the sequence of actions for the preparation of various mixtures for plastering walls.

How to prepare cement mortar for plaster walls

Consider how to dilute cement for plastering interior and exterior surfaces.

Procedure:

1. Carefully sift the sand through a sieve.
2. Mix sand with cement brand M400 in a ratio of 4:1 or M500 in a ratio of 5:1.
3. Gradually add water and mix until working consistency.

The finished mass must be used within half an hour, until solidification begins. The kneading can be done manually using a trough. However, when performing large volumes of finishing work, it is necessary to use a construction mixer.

Preparation of mortar for wall plastering based on lime

In this variant, lime is used as a binder instead of cement. It is necessary to use slaked lime that does not contain foreign inclusions.

Do-it-yourself lime mortar for wall plastering

The cooking process is quite simple:

1. Prepare milk of lime and strain it through a sieve.
2. Pour milk from lime into a container.
3. Gradually add fine sand and mix with a mixer.
4. Strain the finished material again through a sieve.
5. Add water when thick.

The lime composition has a long setting period, which allows it to be prepared in larger portions. It is important to use the prepared finishing material for 72 hours until it has completely thickened.

How to make a mortar for plastering walls using clay

Clay has traditionally been used for centuries for wall cladding indoors as well as outside buildings. The preparation process requires a long time, since it is necessary to pre-soak the dry material.

Sequencing:

1. Fill the cleaned dry clay with water.
2. Stir wet material.
3. Let her rest throughout the day.
4. Break up the clay mass.
5. Add water to a viscous consistency and rub through a sieve.
6. Pour sand in an amount exceeding the volume of clay by 2-4 times.

Clay mortar for plaster

The proportion of sand introduced is determined depending on the fat content of the clay. Modern technology provides for the possibility of adding Portland cement, slaked lime and gypsum powder to improve the strength properties of the clay composition.

How to prepare plaster for interior work based on gypsum

Accelerated drying of the gypsum composition requires quick preparation and prompt application. Gypsum-based mixtures are used to seal local irregularities and finish leveling walls. Cooking according to various recipes is possible.

First option:

1. Mix chalk with plaster in a ratio of 3:1.
2. Stir the mixture with wood glue.

The use of glue instead of water allows you to extend the use time.

The second option is designed for processing chipboard or leveling painted surfaces:

1. Mix gypsum with drying oil in a ratio of 2: 1.
2. Add 3% hardener to the total volume of the mixture.

Due to the accelerated drying, it is necessary to prepare the gypsum mass in small volumes.

The complex composition of the mixture for wall plaster

Mixing plaster mix

To improve operational properties, increase strength and reduce the drying time, several binder ingredients mixed with aggregate are introduced into the mixture. Consider the most popular recipes.

Cement mortar for plaster with the addition of lime

Prepare the cement-lime mixture in the following sequence:

1. Prepare cement, fine sand and lime paste.
2. Prepare lime milk.
3. Mix sand with cement in a ratio of 3:1.
4. Add lime milk in a volume of 12–25%.

The consistency depends on the amount of lime milk.

Another option is possible:

1. Mix sand with lime paste.
2. Add cement and mix.
3. Pour in the water.

The viscosity required for operation is determined by the volume of water added.

Lime mortar for plastering walls with the introduction of gypsum

Lime mortar for wall plastering with the addition of gypsum

Gypsum-lime kneading is fast:

1. Prepare liquid lime mass.
2. Pour gypsum in an amount of 20-30% of the total volume.
3. Mix the ingredients thoroughly.

A feature of the lime-gypsum mixture is accelerated drying time and increased strength.

How to make cement mortar for plaster with clay

The recipe provides for the introduction of cement in a volume of up to 20% of the total amount of clay. Fine river sand is used as a filler, which is mixed with clay before the introduction of Portland cement. This makes it easier to knead and allows you to achieve the desired consistency.

Clay-lime mortar for walls

Perform lime-clay kneading in the following order:

1. Mix diluted lime and clay in a 1:1 ratio.
2. Pour 5-6 parts of the sifted sand.
3. Stir evenly until smooth.

This formulation provides an acceptable margin of safety.

Preparation of plaster mortar based on clay and gypsum

Plaster mortar made of clay and gypsum

To ensure an accelerated setting, adhere to the following recipe:

1. Mix clay with powdered gypsum in a ratio of 4:1.
2. Add 8 parts fine sand.
3. Mix with water until even.

The use of gypsum allows you to speed up the drying process.

Plaster mortar for walls - the main requirements

To ensure reliable adhesion and strength of the plaster, it is important to observe the following recommendations:

• use high quality raw materials;
• sift components;
• strain the finishing mixture before use;
• adhere to the requirements of technology;
• take into account the operating conditions.

If necessary, you can enter plasticizers.

What is the consistency of the plaster mix?

In the process of preparation, it is important to pay attention to the consistency of the plaster mass, which affects the degree of adhesion and mobility of the plaster.

Preparation of plaster mortar with a mixer with a nozzle

By sticking the finishing mass to the surface of the tool, you can determine its fat content.:

• with increased adhesion of the fatty mass, it is necessary to add a filler;
• in a lean solution that lags behind the surface, an astringent should be introduced;
• the mass retains its shape with medium fat content, which ensures normal adhesion.

Along with the introduction of filler and binder, the consistency can be adjusted by gradually adding water.

Summing up

Owning the technology of self-preparation of the plaster mix, you can prepare high-quality material for plastering walls made from various building materials on your own. The strength characteristics and degree of adhesion are affected by the quality and preparation of the raw materials used, compliance with proportions, as well as the implementation of technological recommendations.

A mortar for wall plaster always consists of two or more components, of which one is a binder, the second is a filler. There may be several of these components depending on the place of application, the thickness of the plaster, the base on which it needs to be laid, and other features, but the binders in all plaster solutions are: cement, lime, gypsum, clay.

There are several basic compositions based on these binders that most developers use, but there are no absolutely universal recipes. And yet, first of all, we will talk about them, because they are the basis for the manufacture of more specialized mixtures.

Cement-sand mortar

Such a solution is considered the most versatile, with well-established proportions with slight deviations in the ratios depending on the initial conditions. The main ratio of 1 × 3, where the first is cement M400, the second is sand, is used for most brick walls and walls made of heavy blocks: cinder blocks, expanded clay concrete, sawdust concrete. Moreover, it is used for both internal and external work.

The final quality of the solution is affected by several points, incl. the amount of water and the characteristics of the sand. A more liquid solution will flow down the wall, a thick one will stick worse. The density of the solution is selected experimentally, first of all, depending on the thickness of the applied layer.

There are also such types of plaster mortar:

• bold - when there is more astringent than necessary;
• normal - when the ratio of binder and filler is chosen correctly;
• skinny - when the amount of aggregate is above the norm.

In practice, this is quite easy to check. If the solution is greasy, it is difficult to separate from the tool, while the thin one, on the contrary, does not adhere well to it. If the layer of plaster is 3 - 4 cm, then it is better to use a thick solution of slightly increased fat content, if thin, then leaner mixtures can be recommended for use, they crack less. With layers of plaster more than 2 cm, it is also desirable to use various plaster meshes. In this case, the whole process can be divided into two stages and, accordingly, two different compositions can be prepared: first, thicker and fatter, for finishing, thinner and less thick.

Specialized mortar additives for plaster

Although this is rarely done in practice, some methods are used to improve the physical and technical characteristics, first of all, it is the cement plaster mortar by adding various chemical additives and introducing additional reinforcing elements into its composition. More often, these methods are resorted to when preparing a solution for plastering exterior walls. To increase elasticity, frost resistance, and prevent cracking, the following is introduced into the CPS (cement-sand mixture):

• plasticizers of the C-3 type or the like, even liquid soap can also play this role;
• dispersed PVA glue, in most types of dry mixes it is introduced in the form of a powder;
• non-metallic fibers - thin fibers of various origins: polypropylene, basalt, carbon, fiberglass.

Now how much. Plasticizer 2 - 3% of the total mass of the solution, PVA dispersion from 10 to 20% of the mass of cement, fibers - in a fist for 1 batch of a 140 liter concrete mixer. Well, you won’t measure more precisely how to drink in the process of work. Yes, and these figures will definitely undergo a correction, as they say, "under the working hand." Such compositions, by adjusting the amount of water, can even be pressed with polyurethane or silicone stamps, resulting in the so-called press concrete. Although many people prefer to use ready-made plaster mixtures for this, such as Ceresit CT 29, in which the right amount has already been measured out of all of the above, we are used to doing everything ourselves.

Yes, as a bonus: if you take M500 cement and fine river sand in a ratio of 1x1, add all of the above, introduce a little sifted garnet seed as a filler - you will get the best of polymer concrete compositions. This I mean that by plasticizing and reinforcing the solution, you can very seriously vary the ratio of its main components.

And it would be great if you share your experiments in this area with the readers of our site in the comments.

But if we take white cement, use marble chips as a filler instead of sand, and add an acrylic copolymer as a plasticizer, we get the well-known bark beetle. As you can see, everything is simple.

Option with two binders

It is not for nothing that we paid so much attention to DSP - this is the main composition for plastering the walls of most houses built from materials traditional for our country, and variations on its theme allow you to create a real building symphony. But its possibilities are not limited to this, because the introduction of the so-called. the second binder allows you to further expand the scope of its application.

Namely:

• if a little lime is introduced into the cement-sand mortar, it will become more elastic, it will behave better in rooms with high humidity;
• if a little clay is introduced into the cement-sand mortar, then such a mortar, bringing the composition closer to the characteristics of a brick, will be less prone to cracking, but will soften the plaster, it is mainly used for plastering wooden walls.

That's what you absolutely cannot do, so it's to introduce gypsum into the composition of the DSP. Works great, especially in areas with a thick layer. The speed of work production can be increased significantly. But such plaster will not last long even indoors.

Lime-sand mortar

At home, such a mixture is rarely used, as a result of plaster is too soft. The ratio is usually taken: 1 part lime to 2-4 parts sand. It was used (yes, it is often used now) for plastering large areas in public buildings and structures. You can make a large amount and, under certain conditions, keep it ready for weeks, spending gradually. The solution is easy to use, probably the best for machine plastering, elastic and pliable.

As a rule, a strengthening finish was provided for walls plastered with lime-sand mortar:

• coloring in several layers;
• panel arrangement;
• facing corners or chamfering them, etc.

For a home in its purest form, I would not use, but experiment with using two binders, as described in the previous section.

But if we take slaked lime as a binder, and use the same quartz flour or various smallest particles of stones (practically dust) for filling: onyx, granite, quartz, etc., then we will get classic Venetian plaster. But only certain ways of working with it and materials for finishing will make it uniquely beautiful.

Plaster mortars based on gypsum

For interior work - one of the best options, but requires great skill of the plasterer, due to the speed of drying. Does not allow processing large areas in one go. Such plaster is more expensive than cement-sand, but it is much easier to work with.

But making gypsum plaster mortar yourself today is simply unprofitable, although the principle is quite simple. We take dry building gypsum - alabaster, mix it with sand, add dry slaked lime to slow down the setting and you can work, but still the quality of this solution will be lower than the quality of the finished gypsum mixture, and it is unlikely to be inferior in price to it. Yes, and the sand in such mixtures is calibrated, in isogypsum - larger, in satengypsum - smaller, and some kind of "super secret" chemistry that improves performance. And gypsum-based adhesives such as Perlfix or Rotbant are hardly worth repeating at home.

But to add a little lime to further slow down the setting, in principle, it is possible, but without getting carried away - gypsum plaster is not among the superhard anyway.

A large number of decorative plasters have been created on the basis of gypsum, and even more can be done by yourself, just using a certain tool and special working methods.

Clay-sand solutions

In its pure form, clay-sand mortar in our time is mainly used for laying stoves and fireplaces in a ratio of 1x2 (3), although even here it is gradually pushed into the shade by special masonry mortars. But for plastering, it is necessary to introduce into it, except for sand, sawdust, chaff, sunflower husks, etc. Of course, now you can use fiber.

For a long time I have not heard of someone using such a composition for plastering the walls of their house - only when repairing stoves. But in my house the walls of the hall are plastered by him and rather roughly - antique.

This was also done for additional regulation of humidity in the room, which, although through double doors, had two through exits to the street.

Dear readers, if you still have questions, ask them using the form below. We will be glad to communicate with you;)

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 masonry defects. Strength and durability depend on the correct ratio of the components of the solution.

1. Varieties of cement mixtures
2. Ingredients and their proportions
3. Special dry formulations
4. DIY kneading
5. Plaster consumption

Types of cement mortars

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

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

There are such types:

1. Cement-sand - consisting of cement, sand and water. It is applied to front plaster of walls and a socle in the conditions of the increased humidity. Inside the house is well suited for the bathroom, bathroom, kitchen.

2. Cement-lime - prepared in the same way as the first, only liquid diluted lime is added instead of water. It is used for fine finishing outside and inside the building.

3. Cement Clay - This is an excellent mortar for indoor walls with moderate humidity. Outside, it can only be used in dry climates.

Brand is a conditional concept that depends on many factors. Determine it on a test stand for 28 days. A small cube of hardened plaster is taken as a sample, which is checked for compression. The permissible degree is regulated by changing the ratios of the binder and filler.

Such a complex procedure is more applicable on an industrial scale of construction. In everyday life, the finishing mortar is prepared, focusing on the brand of cement. So for one part of the M400, 4 parts of sand are taken, for the M500 - 5 parts. This simple rule gives average ratios of constituent elements.

By changing the proportions, you can increase or decrease the strength. If, when using the M500 brand, you choose a ratio of 1: 4, you get a strong mixture that is suitable even for laying walls. Strengthening the strength entails an increase in the density of the plaster layer, and this completely changes the technical performance of the cladding.

In heavy dense plasters, thermal conductivity and water resistance increase. They are best used for facade cladding of buildings. Light solutions (M500 1:6 and above) have a decrease in frost resistance, so they are suitable for interior work.

Features of the use of dry mortars for plaster

In the building materials market, multi-component mixtures for wall decoration are often found. They are produced on the basis of Portland cement grade M400 or M500. Contains polymer additives that increase plasticity, improve adhesion (sticking to the working surface) and increase strength.

Advantages:

• Reducing the mass of the structure - when finishing the facade, reinforcement with steel mesh is not required.
• Profitability - for kneading the master spends a minimum of effort and time. In addition, the consumption of the finished mixture is much less than a solution prepared independently.
• Durability - gently reacts to changing weather conditions. Thanks to plasticizers, it does not crack under sudden temperature changes.
• Moisture and vapor permeability - a normal microclimate is maintained inside the plastered premises.

Dry building mixes are developed in laboratory conditions, therefore they differ in the exact proportions of the components, uniformity and readiness for use.

How to prepare a cement mortar with your own hands?

Inexperienced people often make the mistake of first pouring water, then adding the rest of the components. The mixture is mixed with great difficulty and the result is poor quality. Cement, falling into the water, clumps into lumps, which are then overgrown with sand particles. On the walls, a fragile and uneven coating is formed.

1. How to prepare a cement mortar.

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

The prepared solution must be used within an hour. Left unused, 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. Whisking constantly, add water little by little to the desired consistency.
• Cement and dry sand. Prepare milk of lime by combining water with lime paste in a ratio of 1:1. Dilute the sand-cement mixture with milk.

3. Cement-clay.

• Wet clods of clay with water and cover them with a dense rag.
• Mix the swollen clay with sawdust in a ratio of 1:3.
• By adding a little water, bring to the desired density.
• To enhance the strength, add dry cement to the composition and mix thoroughly.

Solution consumption

The smaller the building elements, the more seam joints in the masonry. This directly affects the unevenness of the walls. Deviations from the level can be both vertically and horizontally. It will take a lot of composition to level highly curved surfaces. To calculate its consumption per 1 sq.m., you need to multiply the thickness of the layer and the area of ​​\u200b\u200bthe walls.

To obtain data on curvature, 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 acquire an ideal level.

To find out the maximum value of the 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 must be added, and the sum divided by the number of measurements: (10 + 15 + 40) / 3 = 22 mm. The result is an average plaster thickness. Now it remains to multiply it by the area of ​​\u200b\u200bthe working surface.

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

Cement binder based plaster is one of the strongest and most durable. However, dry ready mixes are quite expensive.

How to make a mortar for cement plaster with your own hands, what other materials will be needed, their proportions? What are the varieties and where is it better to apply them, application methods? You will find answers to these and other questions that arise during the repair in this article.

Varieties and recipe

At the moment, two types of cement binder plasters are most widely used. Their technical and operational characteristics are somewhat different from each other, which determines the optimal scope of their application and application methods.

Cement-sand mixtures

The binder is mainly Portland cement grades M150-500. As a rule, grades up to M300 are used for interior work in dry rooms, M350 and higher are used in compositions for facade work and rooms with high humidity - bathroom, kitchen, etc.

The ratio of sand and cement for plaster depends on the fraction, the required final strength or the application. For example, to apply the middle (ground) layer, sand of medium fractions of 0.5-1 mm is required with a minimum content of clay or silt deposits. Fine-grained sand is used for covering (finishing plastering).

Cement mortar for wall plastering, proportions depending on the brand

Special additives give the cement-sand mixture for plaster additional properties:

• Quartz sand and diabase flour - resistance to acids;

Quartz sand

• Barite and serpentite sands with a fraction of at least 1.25 mm - protection from x-rays;
• Metal shavings or dust added to the cement mortar gives it additional strength and increased impact strength;
• Marble flour and coarse sands 1.5-4 mm - decorative facade coatings.

Colored coarse sand for decorating facades

Various types of sand-cement plaster

Coating type	Type of plaster
	Cement-sand		Cement-lime
	Cement	Sand	Lime	Sand
splatter	1	2,5-4	0,3-0,5	-
Priming	1	2-3	0,7-1	2,5-4
Nakryvka	1	1,1,5	1-1,5	1,5-2

1. Simple - only 2 types of work are performed, spraying and soil without the use of beacons. It is used in internal technical rooms: garages, basements, attics, where aesthetics are not important. The main purpose of sealing bare brick walls.
2. Improved - a covering is added to the previous layers, which must be rubbed with a special iron or grater. Most common when decorating residential premises or exterior walls .;
3. High quality - produced by lighthouses. At least 5 layers are applied (2-3 layers of primer). For coating, ironing with cement is used, which significantly increases the moisture resistance of the surface.

Instructions for the preparation of sand-cement mixture

1. First we sift the sand. For wet, a sieve with holes up to 4 mm is used; for dry, 2 mm;
2. 2-3 liters of water are poured into the container cleaned from the remnants of previous batches;
3. Cement is added and thoroughly mixed until there are no lumps;
4. Based on the proportions given in the tables, the required amount of sand and other fillers and modifiers is added;
5. The mixture is thoroughly mixed until a homogeneous mass is obtained, if necessary, water or a little sand is added.

Important: in order to increase the plasticity of the plaster, 30-50 ml of detergent is added to the water before cement, which is thoroughly mixed in water.

The solution has the correct density if after the elongated mixer there is a hole of 2-3 cm.

Cement-lime mixtures composition and features

To reduce the weight of cement-sand plaster, slaked lime was added to its composition. If the quenching is done independently, then the minimum period of exposure to lump lime is 2 weeks. Otherwise, there is a risk of swelling and peeling of the finish. Properly prepared solution has high strength and vapor permeability.

Important: when preparing the lime mass yourself, do not use plastic containers. The quenching reaction occurs with the release of a large amount of heat.

Advantages and disadvantages

The main advantages include:

• Good adhesion to most materials: concrete, brick, foam block, wood;
• Antibacterial properties - prevents the formation of fungus and mold;
• Good plasticity of the mixture during the entire life cycle;
• High vapor permeability creates a comfortable indoor climate;
• The plastered surface is resistant to mechanical abrasion.

The disadvantages include:

• Decreased resistance to impact and stretching / compression;
• The cost is slightly higher than that of simple one-component mixtures.

Table of proportions of cement-lime plaster ingredients

Application technologies

There are several ways to apply cement-based plaster. Their choice depends on several factors:

• type of base material;
• type of plaster mortar;
• skill of the performer of works;
• availability of special equipment (machine application method)
• Finishing end goal:
  • preparatory;
  • finishing;
  • for painting.

Do-it-yourself plastering of walls with cement mortar, leveling the ceiling on the video:

Lighthouse plastering

1. The walls are carefully examined, all irregularities are noted - bumps and depressions;
2. Two extreme beacons are installed, indented from the corners by 30 cm.
3. Distances between beacons are marked. If a 2 m rule is used, then it is advisable to take 1.6 m.
4. With the help of colored twine, a horizontal line is beaten off on the surface of the base. In the places where it intersects with vertical marks, we drill holes and drive in a lubel. The distance from the floor and ceiling must be at least 15 cm.
5. The surface of the base is primed with compounds that increase adhesion. For concrete walls and smooth surfaces, special mixtures are used - concrete contact.

Plastering walls with cement mortar on beacons, video using plastic beacons:

Foundation primer

1. The extreme (corner) screws are screwed in on both sides and are set strictly vertically along the caps. Between them, twine is stretched over the surface of the hats.
2. The trimming of the beacon checks its placement under the twine, it must pass back to back. The twine is removed.
3. A mixture for fastening beacons is placed along the marking line. The lighthouse is pressed into it so that the surface is flush with the hat.
4. The verticality of the placement is checked using a rule.
5. The walls are plastered with cement mortar along the lighthouses, using the method of capping with a spatula or grouting with a trowel.
6. After filling the space between the two beacons with a layer slightly higher than the upper level, using the 2nd rule, relying on the beacons, we draw the layer from the bottom up.
7. After the plaster has dried, the beacons can be removed from the wall, and the strobes can be sealed. Mortgage plastic models can be left.
8. Grouting is carried out until the plaster is completely dry. A solution is prepared with a more liquid consistency than the main one.
9. The cement surface is pre-wetted, and then grouting at an angle of 45 °, the grout mixture is applied under pressure.

It is important if cement plaster for the bathroom is applied under the tiles, the minimum layer should be 10 mm.

Do-it-yourself plastering of walls with cement mortar, video of work without the use of beacons:

slopes

Plastering slopes with cement mortar is carried out in the following sequence:

1. Slopes are checked for verticality;
2. If the difference is large and a large amount of the mixture is to be applied To strengthen the finishing layer, a mesh is attached to the slopes;
3. The surface is cleaned and treated with a primer;
4. A restrictive rail is installed on the wall bordering the slope, the thickness of the facing layer will be oriented along it;
5. The solution is applied with a spatula to the bevel and carried out along the slope from the bottom up;
6. After the solution has dried up a little, the restrictive strips are removed and the corners are corrected.
7. The plastered surface is rubbed clean with a grater dipped in water.

Plaster door slopes video:

Finishing the slopes after installing the window, video:

Cement-sand VS plaster

In order to find out which plaster is better than gypsum or cement, we will make a comparison according to the main operational and technical characteristics:

Vapor permeability

Cement-sand plaster has a vapor permeability index of 0.09-0.1 mg / mchPa, and gypsum plaster 0.11-0.14 mg / mchPa. The difference is so negligible that it will practically not be displayed in the indoor microclimate. However, this indicator is important for the effect of moisture condensation in the room. For example, the vapor permeability of shell rock is 0.10-0.12 mg / mchPa, and foam concrete and aerated concrete is 0.14-0.17 mg / mchPa, it is recommended to use materials with similar indicators. Therefore, the use of gypsum or cement plaster for wall decoration in interior spaces also depends on the base material.

Consumption and cost

It is a big mistake to compare the cost of gypsum or cement plaster, which is better at a price per pack of 25 or 30 kg. This is fundamentally wrong, starting with the fact that perfect plasters have different specific gravity and ending with different consumption for plastering 1m2 of surface. For 1 cm of the thickness of the plaster layer, the consumption of gypsum mixture is 9-10 kg, and cement-sand - 12-20 kg. Considering that a dry gypsum mix costs, on average, 1.5 times more expensive, but it is used almost 2 times less, the cost of plastering 1m2 of a wall will cost approximately the same.

Pot life of the finished solution

Cement plaster is suitable for use 2 hours, gypsum plaster with additives 1-1.5 hours without additives 30-40 minutes.

moisture resistance

The possibility of using in rooms with high humidity and in facade work has only a cement mixture.

Thermal conductivity and heat resistance

In terms of thermal conductivity, gypsum plaster is ahead, with 0.35 W / m * K versus 0.9 W / m * K. However, cement-lime and with the addition of perlite can withstand heating up to 150 ° C and open fire for a long time.

Plaster or a layer of finishing material applied to the surface during construction work is a mandatory step prior to finishing.

This is a specially prepared building mixture (mortar), which, after drying, hardens, forming a solid, even surface, ready for final processing.

In most cases, it is used to level the walls, correct any defects, as well as seal the technological channels formed during the repair process, for example, when laying new wiring. The surface becomes even, smooth and aesthetic.

The exact proportions of the mortar for wall plastering allow the prepared mixture to perform its function after drying and not crumble over time. To choose it correctly, you need to have a general idea of ​​the types of building mixtures and their purpose. Knowledge of their main components and application possibilities will allow you to easily navigate the existing range and correctly apply the solution for their use.

Types of plaster and their features

Wall decoration can be used outside or inside the room and is divided into three main types:

• standard, as protection against environmental influences (external walls) or correction of surface defects, including leveling, sealing cracks, technological channels and preparation for final finishing with finishing decorative coatings, as a rule, thin-layer;
• protective, acting as an insulator or screen, for example, suppressing noise, retaining heat, or preventing the penetration of radiation;
• decorative, used during the finishing coating (color, stone, Venetian, graphite).

Each type is characterized by a certain composition, the preparation of which requires the exact proportion of mortar for wall plastering.

What is building mix

To prepare a wall plaster mortar, the proportions must include the binder (cement, lime or gypsum), the aggregate, usually sand and water.

Depending on the amount of binder component, they are:

• skinny, characterized by the absence of cracks, but poor strength;
• greasy, able to crumble and shrink.

Skinny mixtures easily slide off the trowel, while greasy ones, on the contrary, stick to it. The task of any builder is to prepare a solution for plastering walls, the proportions of which will be optimal.

In addition, a plasticizer is necessarily added to the finished solution, which makes it easier to work with the mixture. The simplest option is ordinary liquid soap or laundry detergent, but there are also special industrial additives.

Number of layers

The application usually takes place in three layers, which have individual proportions of the wall plaster solution:

• the first (spray) is applied with a layer of at least 5 and no more than 9 mm when filling all the irregularities and looks like sour cream;
• the second (ground) is the main layer, which can be applied several times and has the density of the dough;
• the third (covering), is applied with a layer of no more than 4 mm, always on a damp surface, similar in consistency to a spray.

When preparing a mortar for wall plastering, the proportions differ in the amount of binder, most often cement. In the first layer there is very little of it, in the second the amount increases and in the third it becomes maximum.

Types of mixtures

When decorating walls, several basic types of compositions are used. Today, three mixtures are mainly used:

• cement, the most common and popular, is characterized by the greatest strength, but a long solidification period;
• clay, used during internal and external work in the processing of wooden surfaces;
• lime, an inexpensive analogue of a cement mixture, often used with gypsum, accelerating the setting period and increasing strength.

In addition, depending on the situation, other options may also apply:

• gypsum - the most rarely used due to the rapid (within a few minutes) initial solidification and complete fixation after half an hour;
• mixed - characterized by the use of several special components at the same time;
• special - used with a certain additive, depending on the goal.

One of the important indicators that determine the type of solution you need is the level of humidity. Depending on the microclimate, the desired composition is selected. The most versatile and common is the cement mortar for plastering walls, the proportions of which are known even to an amateur, and allow it to be successfully used both outside and inside the room.

cement mortar

The most reliable, simple and ubiquitous way. To do it, you must strictly follow the order.

Work begins with the preparation of all components and, first of all, sand. It must be dried, and then be sure to sift. Then carefully clean all lumps, especially clay ones. It is not advisable to use red or red sand, this lowers the quality of the finished mixture and its performance properties, and it is generally impossible to use unsifted and uncleaned sand.

After sifting, you can begin to prepare a cement mortar for plastering walls. The proportions vary depending on the type of cement used. For example, using the M400 brand, 4 sand components are enough for 1 part of cement. If an M500 is used, the number of parts increases to five. Violation leads to loss of quality finish and is not allowed. Dry components are thoroughly mixed in a pre-prepared container. This can be done using a mixer inserted into a hammer drill, shovel or concrete mixer.

The choice of method depends on the required volume. If you have to work independently, it is enough to use a large construction bucket of 15 or 20 liters, in which you can prepare a solution for plastering walls with your own hands, the proportions remain the same. If the work is done by several people, it makes sense to use a large trough or a concrete mixer.

Water is gradually added to the thoroughly mixed mixture, bringing the composition to a state of thick sour cream.

Features of lime mortar

In order to reduce costs, cement is sometimes replaced with slaked lime, which has almost no effect on quality. Moreover, the proportions of lime and cement mortar for wall plastering are almost the same.

Its peculiarity is the use of only slaked lime. It is quite easy to make at home without much cost.

The acquired lime is poured with warm, but not hot water in a large container, and after the reaction is completed, it is filtered, usually through gauze. It can be used no earlier than a day later.

lime mixture

Preparing the solution also involves following the sequence.

First, lime is cleaned of lumps by stirring. The use of water or sand in small quantities is allowed. Having received a homogeneous composition, you can proceed to the preparation of the mixture.

The required composition is obtained if three sands, previously sifted and cleaned, are put on one part of the lime mass. Along with the sand, water is gradually introduced. This continues until the solution resembles a thick homogeneous mass. After that, it can be used for 12 hours.

Features of lime mortar during outdoor work

Usually lime mixture is used only in dry climates. If the processing time of the facade is limited, the proportions of the mortar for plastering the exterior walls include a small amount of gypsum.

This allows it to begin to harden within a few minutes, completely hardening in half an hour.

To make a solution, 1 kg of gypsum is added to 3 liters of ready-made lime mixture. But it is necessary to take into account the hardening period and the amount of work, otherwise it will harden ahead of time.

clay mortar

The use of clay is still quite common in wooden houses. To prepare a strong clay mortar for wall plastering, the proportions should include cement, lime or gypsum.

You will need alumina, preferably fatty, which is soaked for several hours. It is important to constantly stir the mixture and add water until it becomes thick.

The easiest way to prepare it is to add sifted sand in a ratio of one to three. But it is not particularly durable. This is corrected by adding 1/5 parts of cement to these components. At the same time, cement and clay, that is, binders, are first mixed, and only then sand.

Sometimes cement is replaced by lime, but with a mandatory increase in the part to 1/2. You can also add gypsum, but not more than 1/4.

Component ratio

The proportions of different components in the finished solution always differ, depending on the task and the type of layer. Typical ratios are shown in the table below.

The specified proportions are not constant and can be adjusted in each individual case.

Ready dry mixes

Today, almost all manufacturers provide a wide range of ready-made dry mixes. All that is needed before starting work is to take the required volume of water and the finished dry solution, after which everything is thoroughly mixed, usually twice. The mixture is ready to use. As a rule, they are always slightly more expensive than the cost of the included components if purchased separately.

Their main advantage is that there is no need to mix several different elements in the right proportions. In addition, bulk materials are sold in large quantities, which is not always convenient. For example, it makes no sense to buy a bag of cement weighing 25 kg if you need to patch up a small hole in the wall. Therefore, with a small amount of work, a ready-made dry mix will be a good alternative.

Working with plaster

Properly selected proportions of mortar for plastering interior or exterior walls are one of the key points of any repair. But even the ideal ratio will be useless if the plastering is carried out in violation of the rules for applying to the surface. Therefore, it is necessary to pay attention to all stages without exception. Only in this case can a positive effect be expected.

The sequence, thickness and number of layers is as important as the composition. A mistake can lead to the most unpleasant consequences. The application is carried out with a special tool, with a mandatory time interval provided for each type of mixture.

With minimal experience in carrying out such work, it is recommended that a mandatory number of trial attempts be made in small areas in order to assess one's own capabilities.

Tools and specifics of individual surfaces

If the work is done by hand, you will need a certain construction tool:

• rule;
• Master OK;
• level;
• spatulas of different sizes;
• cord;
• grater for grouting.

The application of the first and second layers is carried out with a trowel, the third - with a spatula. Typically, the first layers are applied to an auxiliary mesh for reinforcement. When applying the finish coating, a gypsum mixture is used.

Surfaces with large differences are processed using special building beacons, which facilitate the process of applying and leveling the plaster.

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

1 Features of plastering - 3 layers

It is easy to make a solution for plastering walls with your own hands. It is necessary to level the surface. This operation is required both when carrying out external finishing, and internal. From the place of application of the essence depends on the characteristics and requirements. So, to carry out repair work indoors, a technological and plastic mass will be needed, while outdoor mixtures must first of all be resistant to pressure and temperature changes, frost-resistant and resist moisture.

Solutions are applied on surfaces of all types and types. Plastering of plywood, chipboard sheets, wooden elements, cinder blocks and foam concrete, brickwork, concrete is carried out. When making 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 layer that needs to be applied to the building substrate. It is necessary to fill and level the largest pores and surface defects, as well as to ensure an appropriate level of adhesion and adhesion of subsequent plaster layers. When forming it, additional elements, such as lime and clay, are not used, and the thickness of the coating should not exceed 4 mm.
• The second level, which was called the soil, significantly exceeds the previous one in volume and reaches 20 mm. Unlike liquid spray, this layer is more consistent with a thick plastic dough with its consistency. Its task is to maximize the leveling of the base plane, regardless of its roughness.
• The last stage of work is the application of a coating to the surface, which is required for the final smoothing of irregularities and defects in the base. The formation thickness is from 3 to 5 mm, and so much water is added 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.

2 What ingredients are needed to prepare the mixture?

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

Clay and lime can play the role of a binder. But the most popular and in demand 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, since the rest of the ingredients are seriously inferior to it in terms of quality, reliability and strength.

Choosing among the many varieties, the easiest way is to stop at M400 brand cement. This dry mix is ​​universal, as it meets all the requirements of GOST, as well as apartment owners. Great for bathrooms, kitchens, hallways and naturally living rooms. If the budget is limited, and repairs are carried out in low-responsibility structures, such as basements or plinths, then the purchase of Portland cement M300 would be a rational solution.

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 turn out.

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 pure river fine fraction, which will ensure maximum mixing of all the ingredients of the future plaster. Together with cement, it forms an ideal material that is resistant to cracking and has a high level of strength.

The simplest and most popular proportion of the preparation of a cement-based plaster mixture includes one share of a binder and three parts of sand. This recipe is suitable for almost any room. Water is added until the essence of the required viscosity level is formed. For rooms with a normal level of filler moisture, you can add a little more. If plasticity is required, then the correct ratio involves the use of one portion of cement and two parts of sand.

There are many plasticizers and additives designed to increase the softness and pliability of the finished plaster, change the setting time and various characteristics of the mortar. Home craftsmen often add detergents, soaps, adhesives, like PVA. Thanks to such materials, the adhesion of the essence to the concrete base improves, and the level of protection against fungal bacteria and mold increases.

A big misconception is associated with the technology of mixing the mixture. For some "specialists" the order in which components are added does not matter. Many first pour water into a container, then pour in cement, sand, lime and other materials. The problem is that the dry matter, after entering the liquid, is converted into small lumps. It will take a lot of effort to stir them until the consistency of the required level is obtained.

In order for the solution to turn out to be of high quality and homogeneous, experienced craftsmen advise doing the following:

1. 1. Initially, it is required to sift the sand using a sieve with small cells. Otherwise, all debris and large particles, such as shells, pieces of silt, pebbles, organic residues, will be in solution. During plastering, they will leave grooves on the surface of the wall, clinging to the spatula.
2. 2. After that, it is necessary to 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 that water is added, and gradually, while the solution itself is constantly mixed. It is recommended to pour in new portions of the liquid at a time when it is almost impossible to interfere.

3 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, a solution boasts great popularity, an astringent in which cement and lime act. Such an essence perfectly tolerates low temperatures, exposure to direct sunlight, counteracts the appearance of mold and fungi.

Unlike conventional cement plaster, lime analogues are characterized by a high level of plasticity and viscosity. This has a positive effect on their adhesion index, due to which they instantly and firmly seize with the bases of walls and ceilings of any type and type.

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

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

Decorative cement mortars and glazing plasters, which require additional investments of money and effort, are very popular. With the help of such mixtures, you can finish the finishing of halls, corridors and hallways. In addition to the main binders, 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 in color pigments. You can buy all these additives in the same hardware store where bags of cement and lime are sold.

If you plan to apply a decorative mixture in baths or near the stove, then you will need to increase the level of resistance and resistance to extremely high temperatures. To do this, it is recommended to pour fireclay 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 even the walls of fireplaces can be treated with it.

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

Mixing of all components of the solution is carried out in two ways - machine and manual. The easiest way is to prepare the mixture in an ordinary enameled bucket or other similar container. Having added cement and sand and thoroughly mixed everything, it remains only to pour in 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 solution, it is recommended to use a special trough or bath. Here, blunt shovels or bayonet shovels, as well as choppers with a flat base, are used to mix the components. To simplify the process somewhat, experts advise performing movements on yourself, otherwise the arms and lower back will get tired too quickly.

If there is a construction mixer, then it greatly simplifies the work. Any suitable element acts as a nozzle, be it a curved wire or a blade. Concrete mixers also make it easier to mix the mortar, but their operation is only advisable if the volumes of plaster are very large.