Recipes for preparing the main types of mortars for plastering walls. Plaster mortar: proportions for preparation The ratio of cement mortar for plastering walls

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.

Probably, it does not seem new and everyone has long known that modern plaster mortars using new technologies are produced 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 the solution for plastering works, 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 plaster mortar, the type of surface, the purpose of the room and the amount of money for plastering, in the end, take place.

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 both 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.

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 in to a greater extent Ready-made packaged lime dough is 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, this is the grade of gypsum G-2, G-3, G-4, G-5 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 degree firing

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 rocks are used semi-precious stones. In addition, they may contain impurities; the grains themselves can be various 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 on construction site where the cooking work takes place plaster mixture. 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. In this case, 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 formation process 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 plaster solution

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 are poured directly into the container when preparing the composition for plaster. Next, we will consider these components in more detail and describe their operating principle.

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).

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 supplements are presented as complex chemical substances, having complex mechanisms of influence on the binder, allowing 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’s difficult to explain the principle of operation, but everyone knows that salty 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 water in the solution and preventing its delamination. 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 conjunction 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 mortar is an indispensable material for repairs, insulation, leveling and even decorative finishing various surfaces inside and outside the building. But for each type of work a certain composition is used.

For example, to align interior walls Lime mortar is excellent for plaster (see how to make it correctly) - the proportions and ratio of all its components can be different. What do they depend on and how are they selected?

First, let's find out what components can be included in protective and leveling mixtures, and what they are. The required ingredients are water and sand, which acts as a filler.

And the basic properties depend on the binders, which can be cement, gypsum, lime or clay. Their proportion for plaster relative to water and filler determines the quality of the solution.

Component Specifications

To understand why one solution is used for plastering the plinth, another for facades, and a third for interior walls, you need to know the properties of the materials from which it is made:

• Sand. It differs in the size of the fractions and the place of extraction. Pure river sand is considered the best for plaster, but it is also sifted before use to remove foreign matter and large particles.
• Cement. After hardening, it acquires high strength, resistance to water and weathering, and can withstand serious mechanical loads.

For reference. Cement happens different brands: 50, 100, 200, 300, 400, 500, 600, 800. These numbers indicate the resistance of the material to compressive force, expressed in kg/cm2.

• Lime. It can be slaked, quicklime, white, gray, etc. Durable, slow-hardening material that shows good performance in dry rooms. But it is not waterproof and does not withstand weather conditions well.

• Gypsum. A fast-hardening material with low strength and poor resistance to moisture - it quickly absorbs it, losing its properties. Can be added to lime to speed up setting, but is incompatible with cement.

Types of solutions

The composition of the plaster is selected depending on where and on what surfaces it will be used.

In this case, the above properties of the components are taken into account:

• Lime (see Prepare your own lime mortar for plaster). The proportions for the plaster solution depend on the fat content of the lime paste: add from two to five parts of sand to one part of it. First, mix these components in equal parts, then add water and mix until lumps are eliminated, after which, if necessary, add sand in portions to obtain a solution whose consistency resembles a viscous and thick dough.
• Lime-gypsum. In addition to sand and lime, it contains gypsum, which speeds up the hardening of the solution and complicates working with it, but the surface also gains greater strength. Gypsum is usually taken one part to five parts lime.

Advice. If you are going to plaster with your own hands, remember that this solution begins to harden within 5-6 minutes, so you need to prepare it in small portions and use it quickly.

• Lime-cement. Adding lime to cement mortar increases its heat-saving properties. The ratio of cement-lime plaster can be different depending on its purpose. These are listed in the table below along with the proportions for other plasters. But you should know that lime absorbs moisture from the solution, so to prevent it from drying out quickly, the finished surface must be covered plastic film, otherwise cracks will appear on it.

Note. Lime significantly extends the setting time of cement mortar; it can remain viable for up to two days.

• Cement. This is the most commonly used plaster solution with a wide range of applications. It is used to decorate the facades and plinths of buildings, walls in utility rooms, as well as in residential buildings characterized by high or unstable air humidity (see Let's look at how to plaster with cement-sand mortar). It is worth talking about it in more detail.

What you need to know about cement plaster

The main thing to remember: the proportions of water-cement-sand in plaster depend primarily on the brand of cement. The higher it is, the less binder is required to prepare a solution of one brand.

As a rule, instructions for performing a particular type of work contain information about what brand of plaster mortar is required in a particular case. The highest M100 is obtained by mixing one part M400 cement and three parts sand. The amount of sand decreases with increasing grade of cement and increases with its decrease.

Since the price of high grade cement is higher than low grade, and sand is cheap or even mined independently on river banks, to reduce costs while maintaining the required quality of plaster, it makes sense to buy binder of the most popular grades M300 and M400, rather than spend money on expensive material.

Failure to comply with the proportions leads to changes in the properties of the plaster:

• If there is too much cement in it (greasy mortar), then when it dries it will shrink greatly with the formation of cracks;
• If you transfer sand (a thin solution), then most likely there will be no cracks, but the coating will not have sufficient strength.

How to properly prepare plaster mortar

Preparing plaster mortar is also not an easy task; it must be done according to the rules. If everything is clear with ready-made mixtures: they are simply filled with the required amount of water and mixed, then when self-production all wrong.

First you need to prepare the dry mixture itself, determining the proportions for plastering brick, concrete or other surfaces, taking into account their location (inside or outside, in a dry or wet room).

So:

• Dry ingredients are poured into a mixing container. It can be plastic, metal or wooden box with a flat, smooth bottom. Moreover, sand is poured first, and binders are placed on it in an even layer.
• All ingredients are thoroughly mixed using a shovel or trowel if the volume is small.
• Then the mixture is leveled and its color is observed. It should be uniform, without streaks or stains of binder.
• If this is not the case, continue stirring until an even color is obtained.
• Then the dry mixture is poured with water or lime milk, let it absorb and mix well. This can be done manually or using a construction mixer.

It is important that there are no lumps left in the solution, and no unmixed dry matter in the corners of the container. The viability of a solution depends on its composition. Cement-lime ones last the longest, while gypsum ones should be used as quickly as possible.

Conclusion

No renovation or construction project is complete without building mixtures, and the most popular is plaster. If you know how to prepare it correctly, then you will not have problems either with its application or with the quality of the finished surface. To learn more about this topic useful information, we recommend watching the video in this article.

Plaster is an integral part of almost any renovation; it performs different functions, and therefore is used quite often. Sometimes it is simply impossible to do without it - this applies to certain stages of both internal and external work. And today we will tell you how to make a plaster solution yourself.

Before we learn how to prepare plaster ourselves, we should take a closer look at this type of finishing material. Yes, plaster is a mortar widely used in construction and repair work. It consists of water, sand and a mixture of some binders - fillers (the composition will be discussed in more detail later).

Plaster performs the following important functions:

• decorative(that is, using plaster you can decorate walls and other surfaces);
• restoration(using it, you can level crumbled walls);
• sanitary and technical(that is, a surface covered with plaster will be cleaned better than, for example, ordinary concrete. And dust will settle on it in smaller quantities);
• protective and constructive(plaster protects the surface from negative external influences).

It is interesting that plaster, or rather its analogue as finishing material used many centuries ago in the Roman Empire. It was there that cement and concrete were invented, and soon plaster appeared, which quickly gained recognition among the nobility. Although the walls were plastered in those days even by far from wealthy townspeople.

Decorative plaster also appeared during Ancient Rome. After the sculptural work, the Romans had a large number of marble dust, which they added to ordinary plaster and obtained material for decorative finishing.

Important! Nowadays, plaster has become more improved, received additional qualities, and improved its properties. Now on the market you can buy the most different materials for finishing, differing in structure, purpose, composition, etc.

Types of plaster

Plaster now has a huge variety, which allows you to choose a material that is ideal for a particular case. For ease of selection, experts have created a certain classification of this material.

Plaster can be polymer and mineral. The first type is made using acrylic and silicone and is practical, durable, and strong. But mineral plaster is environmentally friendly pure material, which not only does not harm human health, but also normalizes the microclimate in the house (if we are talking about interior decoration) due to the fact that the composition includes natural fillers - chalk, lime or cement.

Also, all types of plasters can be divided into several types according to the purpose of their use and purpose - from this point of view they are:

• decorative, that is, they are used to give the surface being finished a finished look. Apply after the normal plastering process;
• ordinary, thanks to which the walls are leveled, their surface condition is brought to ideal smoothness. Also ordinary plasters used for finishing external walls and protecting them from negative external influences;
• special, which are used for the purpose of sound or heat insulation.

On a note! Decorative plaster, in turn, can have a lot of subspecies. For example, there are stone, colored, Venetian plaster, as well as silk, sgraffito, terrazite. They all differ from each other in the purpose of use, the end result, and the method of application.

Table. Types of plaster by composition.

On a note! There is also magnesium plaster, intended exclusively for interior work. This is a non-flammable, non-dusting composition. It is highly durable and suitable for preparing walls for painting, laying tiles, and wallpapering walls.

There are also combined formulations. One composition may contain several different components that give the solution viscosity - this could be, for example, lime and cement, as well as gypsum and lime, and other variations and combinations.

What should the plaster be like?

The plaster mortar, like any other building mortar, if it is ready for work, must have a homogeneous state without lumps, optimal fat content, and adhere well when applied to work surface, and also not to shrink too much when drying, that is, not to become covered with cracks.

Plaster solutions are:

• skinny;
• normal fat content;
• fatty.

The first solutions have a liquid consistency, since too few binders are added to them. But the latter, on the contrary, contain an excess of such components, which is why during the drying process such plaster becomes covered with cracks and the whole work in progress down the drain. The first type of solution, on the contrary, has a small amount of astringent components, but an excess of filler substances. Because of this, the layer of plaster applied to the wall will have low strength.

The best option is a solution of medium fat content. It is in it that the content of the components included in the composition is optimally balanced.

On a note! Depending on the purposes for which the plaster solution is used, mixtures of different fat content are prepared.

Determining the fat content of the mixture before applying it to the wall is quite simple - you just need to mix the solution and pay attention to its “behavior”. If the mixture sticks excessively to the paddle used to stir it, the solution is too greasy. If it does not stick at all, it will be considered skinny. In the first case, filler is added to correct the situation, in the second - a binder.

Recipes

In order to prepare the working plaster solution as needed, it is important to know the recipes that are suitable for each case. The main ones are presented in the table.

Table. Recipes for preparing plaster solutions.

There are plasters that, in addition to their main functions, perform other tasks: they increase heat and sound insulation, protect against harmful radiation, give the base fire-resistant properties and so on. Special ones include those used for finishing surfaces exposed to increased moisture.

Construction dry mixtures

Often, builders do not want to bother with preparing homemade solutions for plastering walls. It is much easier for them to buy a ready-made mixture based on Portland cement, which is called dry construction mixture and has been actively sold in the markets for many years. This product contains various additives that make the finished plaster plastic, durable, and more sticky relative to the working surface.

Advantages of dry construction mixtures:

• they are elastic, which makes them resistant to temperature changes and changes in weather conditions;
• practically not deformed;
• do not need reinforcing mesh;
• economical, as they allow you to cook required quantity solution without excess;
• diverse, which makes it possible to select a specific mixture for each type of work;
• “breathe”, allowing air to pass through, and are not destroyed by moisture.

The recipes for these mixtures are developed in special laboratories, thanks to which the proportions of the components included in them are verified very accurately. Due to this, the compositions in a diluted state are as uniform in consistency as possible. Having thinned this plaster, you can immediately begin work.

How to prepare plaster

At home, you can prepare any type of plaster mixture yourself. Let's make the simplest one on a cement base.

Step 1. First of all, let's prepare everything necessary tools and components: sifted river sand, cement, water, detergent, container in which we will mix the mixture, as well as a mixer with which we will mix.

Attention! Detergent is used to prevent the mixture from shrinking too much during drying.

Step 2. Add a couple of caps to a bucket of water detergent. Stir with a mixer.

Step 3. Pour the prepared liquid evenly into the sand placed on a wooden stretcher.

Step 4. Using a construction mixer again, mix the sand and the soap mixture poured into it. The solution should reach a mushy state.

Attention! We add water gradually - there is no need to pour out the whole bucket at once, so as not to make the mixture too liquid.

Step 5. Spread the cement evenly over the surface of the mixture in a stretcher.

Step 6. Mix the mixture with a mixer and add a little water again. Mix the mixture again with a mixer. Using a spatula, remove dried pieces of mortar from the walls of the stretcher and mix them in a “common cauldron.”

The plaster solution is ready and can be used for finishing.

Advice! It is advisable to sift all materials that will be used to prepare plaster through a sieve. This procedure will achieve a more uniform consistency.

Video - Preparation of plaster solution

Rules for preparing mortar for plaster

So that the solution for finishing the walls turns out best quality, certain rules must be followed.

The main thing is to adhere to the basic rules, and then the plaster will turn out to be of the highest quality and will last in its applied form for many years.

Sand and cement plaster remains the most popular finishing material used to level surfaces. The low price of the material, its resistance to moisture and frost, as well as sufficient strength and durability have determined the popularity of this coating among builders.

We will tell you in what proportions the mixture for plaster should be prepared, and give a series useful recommendations for those who intend to work with their own hands.

Cement-sand plaster

Composition and features

The photo shows the process of plastering the facade with a cement-sand composition.

Cement-sand composition refers to simple (ordinary, classic) plasters and is used for leveling walls outside and inside premises.

The solution for applying to the wall consists of three main components:

1. Cement. To prepare plaster mixtures, as a rule, Portland cement of grades M200 - M500 is used; the plaster does not require special strength, so for interior work it is enough to use grade 200, but for this purpose material of grades 400 or 500 is better suited. wet areas, kitchens, plinths and slopes, you should also use cement grade M400 - M500;
2. Sand, what sand is best for plastering? Almost any purified sand will do, but it is better to use quarry or “hog sand” ( yellow color) with an average fraction (20 – 40 µm). It is undesirable to use material with impurities of silt, dust particles and clay, as well as unsifted and littered material; in addition, do not buy sand that is too fine or coarse;
3. Water. To prepare the solution, water is added to the dry mixture of sand and cement. Any will do pure water, technical, river, drinking, water or well.

Thanks to such a simple composition and natural ingredients, the solution hardens when dried and creates a durable and even coating, which, if the correct proportions and application technique are observed, can last for decades and even centuries.

The material is not afraid of moisture and frost, so it can be used both inside and outside the house, as well as in utility rooms, basements, technical and unheated rooms.

To improve some properties of the material, various impurities are added to the plaster mixture:

• Lime. As a rule, a small amount is enough - about half of the cement - to improve the rubability and reduce the mass of the solution, as well as to increase the moisture resistance and ductility of the material;
• Gypsum. A small amount of gypsum accelerates the hardening period of the solution, which is important when applying it to the ceiling or in hard to reach places. It should be remembered that you simply will not have time to apply a large amount of such a solution on the wall, since it will harden right in the trough;
• Liquid soap. Increases the plasticity and stickiness of the solution, allows you to create more even and smooth surfaces, and prevents the material from cracking;
• PVA glue. Is in a simple way polymerization of the solution, creating simplest option polymer cement plaster. Increases ductility, adhesion, strength and quality of the coating, extends service life and prevents the material from cracking.

Important!
When choosing components for the mixture, be careful and do not neglect their quality, since the ease of working with the material and its service life will depend on this.

Proportions and consumption

The ratio of sand and cement for plaster depends on the brand of cement used and the area of ​​application of the material. The classic cement/sand ratio is 1:4 or 1:5. This is for the base layer.

For spraying, thicker mixtures are used - 1:3 or 1:2.5, and for the coating layer you can use the most durable compositions - 1:2 or 1:1.

The proportion also depends on the place of application of the material: for interior work in dry heated rooms, 1 part of sand to 4 - 5 parts of M400 cement is sufficient. For facade works and plastering bathrooms and basements, it is better to use 2 - 3 parts of sand to one part of M400 cement, or 3 - 4 parts of sand to one part of M500 cement.

Lime is added only after it has been completely slaked with water for several days. The maximum amount of this additive should not exceed the amount of cement, and most often a smaller proportion of lime (0.5 - 0.7 of the volume of cement) is sufficient.

The consumption of sand and cement for plaster with a ratio of 1:4 and a layer thickness of 2 cm will be approximately 5 - 6 kg of cement per square meter of surface, and about 18 - 20 kg of sand. In other words, one bag of cement and about 60 shovels full of sand is enough to plaster 8 square meters flat surface layer 2 cm.

To create relief surfaces such as “Grotto” or “Venetian”, decorative mixtures are used, which include quartz sand of various fractions. As a rule, to prepare such mixtures, material of five or more different fractions is used, as well as many additives and polymer additives.

Important!
Having chosen a specific recipe for preparing the solution, adhere to this ratio of components throughout the entire work, otherwise parts with different proportions of components will not combine well and crack at the boundaries of contact.

Installation

For your convenience, we have compiled step-by-step instruction for applying leveling plaster mortar to the wall:

1. We clean the wall from dust and prime it with a universal deep penetration compound;

The durability of the plaster both inside and outside the building depends on the quality of the prepared mortar, no matter what type it is. All modern plaster solutions are made from dry mixtures. They are mixed with water in a certain amount of proportions, which is indicated on the packaging. These mixtures are convenient to use, but work with their use is not cheap. This is explained by the presence of modifiers, plasticizers and fillers in their composition. Regular solution, prepared with your own hands, is much cheaper, and its quality is no worse than store-bought.

Proportions for preparing the solution yourself

The main component is a binder. This role is played by cement, lime, gypsum or clay. The latter material is rarely used. To the selected binder you need to add a filler - sand. And these two ingredients are diluted with water to the desired consistency. Their ratio depends on the characteristics that need to be obtained.

The fat content of the solution plays an important role. It must be especially maintained when dealing with clay and lime compounds. Based on its indicator, you can determine whether there is enough binder in the mixture or not.. Depending on this, solutions are divided into fatty and lean. For facing work, it is better that the mixture is normal. This is determined by its fluidity and setting.

If the composition sticks when stirred, then it is fatty; otherwise, it is thin. Bring it to normal condition Adding a binder or diluting with water will help.

Finishing with thin plaster at speed can lead to cracking of the base. In addition, it does not adhere well to surfaces. Its oily consistency can cause excessive shrinkage and, when drying, deep cracks will appear on its surface.

The video shows the preparation of plaster mortar:

Kneading:

1. the prepared materials are sifted through a sieve. It can be with cells 3x3 and 5x5 mm;
2. It is better to prepare the solution in a special box, up to 20 mm high;
3. All components are mixed one by one in the indicated proportions using a wooden paddle, the length of which is about a meter. The resulting mixture must be homogeneous, otherwise it will affect its adhesion;
4. After receiving the solution, it should be checked for fat content. This is done simply: the paddle is inserted into the resulting mixture; if, when it is removed, a little mixture remains on it, then it is prepared correctly. If there is strong sticking, filler must be added, and if the mixture does not stick to the surface of the oar, then a binder is added to it.

The video shows the proportions for the plaster mortar:

When choosing a type of composition for plaster, it is necessary to take into account the material of the surface on which it will be applied:

• external stone and concrete facades require the use of Portland cement and Portland slag cement as binders;
• wood and plaster surfaces they are forced to use combined lime mixtures, which contain, in addition to the main binder, clay or gypsum;
• cement and stone walls indoors they interact well with solutions based on lime and cement; they can also consist of different types of binders.

Types of mixture and classification

Maintaining the correct ratios of the components included in the mixture is the main requirement for plaster solutions. Their meaning depends on the selected material. All solutions are divided into types and are called the main binder component. :

Lime plaster

It differs from all other compositions in its bactericidal properties; even many years after use, it will prevent the development of microorganisms on its surface.

There are two types of such a solution: air and hydraulic. They both have good plasticity, are perfectly applied to the surface and leveled. After their application, you can fine-tune the surface in the form of grinding, either manually or using special device. The main difference between these two types of lime composition is the degree of plasticity and setting time. Hydraulic lime mortar adheres stronger and faster to the surface than air mortar, but the latter is easier to work with, since it is the most plastic.

The proportions of the lime composition depend on the type of lime and its condition (loose or compacted). The most commonly used portions of building materials are:

• 1 part cement;
• 3-5 parts of sifted sand;
• a little liquid detergent;
• one part of the lime mixture, or rather dough.

In the video - lime plaster mortar:

The last component is prepared from lime and water in proportions 1:3. The liquid should be slightly warmed before use to cause it to react with the lime component. All the lime is poured into the prepared container for the solution and filled with half the specified volume of water. After the reaction has passed, the rest of it is added, the components are mixed, and left to mature for a day. It is better to choose a container with a lid for these purposes.

After 24 hours of exposure, the composition is diluted to a liquid state and poured into a previously prepared hole, into which sifted sand is then added, and earth is poured on top of it. The total height of the earth-sand mixture is half a meter.

The resulting composition is aged in a pit for 15-20 days. After this, the resulting lime paste is ready for use, and it is added to the solution to create plaster.

How to cook:

1. lime paste is poured into the prepared box;
2. then cement and a small part of water are introduced into it. The mass is kneaded until smooth; there should be no lumps in it;
3. sand and the rest of the water and a little liquid soap are added. It acts as a plasticizer and serves to give the composition even greater plasticity.
4. the resulting mass is checked for fat content, if it is the desired type, then you can apply plaster.

Lime mortars must be used within 24 hours after their preparation.

Sand-cement composition

This solution is the most used, it is strong and waterproof. It can be used as for internal surfaces Houses.

There are several types of cement, the most commonly used are fast-hardening types. The ratio of components included in the solution depends on the brand and selected cement. If you use an M 400 bag, then you need to take 4 bags of sand to get the desired grade of M 100. If you use M 500, you need to take five times more filler.

Due to these features of this material, on average one part of cement takes:

• 3-5 servings of sifted sand;
• water, how much the composition will absorb until the desired mass is obtained;
• a little detergent.

It is worth considering that plasticity depends on the sand content. Solutions with less of it are labor-intensive to work with, as they do not spread well.

Step-by-step preparation:

1. First, sand is poured into the box;
2. then it is sprinkled with cement and the components are thoroughly mixed together;
3. Water is added with constant stirring. It must be added until a creamy solution is obtained;
4. The last step is to introduce liquid soap and PVA glue, which will ensure rapid adhesion of the material to the surface.

The video shows a plastering station for sand-cement mortar:

The prepared composition must be used within an hour, after this time it will lose its properties and subsequently will not hold up well. Based on this, it is advisable to mix cement mixture in small portions so that you can use it completely in one go.

Lime-gypsum

Gypsum differs from other binders in its ultra-fast setting ability. For plastering work, its grades G3-5 are used, which can be of three different grinding sizes:

Their division depends on the grain size; the limits of the values ​​of each of the subgroups are specified in the technical specifications for this material. For plastering, building gypsum with any grain structure is used.

The grades of gypsum material used can be produced in two ways:

1. using heat treatment followed by annealing;
2. without annealing, they are produced using new technologies.

Before diluting such a solution, it is necessary to carry out all preparatory work and use it immediately after kneading.

Step-by-step preparation:

1. prepare one share of gypsum (alabaster) and three times as much lime paste;
2. combine gypsum with water to form thick sour cream;
3. add the lime component to the resulting mixture and mix.

The resulting composition sets very quickly, so it must be used quickly, only five minutes are allotted for this. Complete hardening of the solution occurs after half an hour. You can read which gypsum plaster is considered the best.

In the video - “build not rebuild” about plaster mortars:

Features of using plasticizer

To improve the quality of the solution, various modifiers and plasticizers are used. Their effect is reduced to enhancing the properties of the binder component.

Plasticizers improve the elasticity and plasticity of the main component of the plaster solution. With their help, laying the material is easier and you can achieve a more even surface. In cement mortars they prevent shrinkage. In addition, they do not allow water to escape from the fresh solution, and thus extend the period of its application, and after the material dries, they prevent cracking.

Sometimes it is used instead of building lime; it performs well when added to a cement-sand mixture, and does not have the disadvantages of the lime component. Thanks to the plasticizer, the cement mortar adheres better to the surface being treated. You can work with the finished composition longer than with its analogue without a plasticizer.

The video shows a plasticizer for plaster mortar:

Wall cladding is an important stage construction work. If you choose the wrong solution or do not maintain its proportions, then over time cracks will form on the surface, which will soon become noticeable on the decorative layer. It turns out that the strength and durability of the plaster depends entirely on the quality of the solution. Special additives - plasticizers - are responsible for its uniform application; at home they are replaced with liquid soap or PVA glue. It is popular for interior decoration, for exterior finishing– . Also about the difference between plaster and putty.