Plaster is an integral part of almost any repair, 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 works. And today we will tell you how to make a mortar for plaster yourself.

Before we learn how to prepare plaster on our own, we should get to know more about this type of finishing material. Yes, plaster is a solution that is widely used in construction and repair work. It consists of water, sand and a mixture of any binders - fillers (more about the composition will go further).

Plaster performs the following important functions:

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

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

Decorative plaster also appeared in ancient Rome. After the sculptural work, the Romans left a large amount of marble dust, which they added to ordinary plaster and received material for decorative decoration.

Important! In our time, plaster has become more advanced, has received additional qualities, improved its properties. Now on the market you can buy a variety of materials for decoration, differing in structure, purpose, composition, etc.

Prices for various types of decorative plaster

Decorative plaster

Types of plaster

Plaster is now very diverse, which allows you to choose the material that is ideally suited in a particular case. For ease of selection, specialists have created a certain classification of this material.

Plaster can be polymer and mineral. The first type is made using acrylic and silicone, characterized by practicality, durability, strength. But mineral plaster is an environmentally friendly material that not only does not harm human health, but also normalizes the microclimate in the house (when it comes to interior decoration) due to the fact that the composition includes natural fillers - this is 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 finished surface a finished look. Apply after the usual plastering process;
• ordinarydue to which the walls are aligned, bringing the state of their surface to perfect smoothness. Also, conventional plasters are used to decorate external walls and protect them from negative external influences;
• specialwhich are used for the purpose of sound or thermal insulation.

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

Table. Types of plaster composition.

View	Description
	It consists of cement, coarse sand, slaked lime (the last two components are mixed in a ratio of 4: 1). This material can be worked quickly, it is applied well. At the same time, the finish is environmentally friendly. The disadvantage is low strength.
	The result of wall decoration with such a material is a perfectly smooth white surface. Such plaster is used only for indoor work. The cost of the material is quite high, in addition, it is afraid of moisture and has a low strength. Unfortunately, asbestos or other chemical additives can often be added to the gypsum plaster, which makes the plastered surface as white as possible, which saves on the purchase of finishing putty, but negatively affects the state of health.
	Such plaster can be used both outdoors and indoors. This is one of the cheapest types of finishing material, but at the same time it is highly durable (the service life is more than one decade), but it is applied quite hard. But such a plaster allows you to close up serious flaws. Composition - sand, cement (4: 1 ratio), to which PVA glue or lime is mixed.
	This type of putty is used for leveling wood surfaces, as well as for decorating stoves, fireplaces, chimneys and other stone products.

On a note! There is also magnesia plaster, intended exclusively for internal work. This is a non-combustible, non-dusting composition. It is characterized by high strength and is suitable for preparing walls for painting, laying tiles, wallpapering the walls.

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

What should be the plaster?

Plaster mortar, like any other mortar, if it is ready for use, should have a uniform state without lumps, optimal fat content, hold well when applied to the work surface, and also not too shrink when dried, that is, not be covered with cracks.

Plaster solutions are:

• skinny;
• normal fat content;
• greasy.

The first solutions have a liquid consistency, since too few binders have been added to them. But the latter, on the contrary, have an excess of such components in their composition, which is why during the drying process such plaster becomes cracked and all the work goes down the drain. The first type of solution, on the contrary, has a small amount of binders, but in excess - filler substances. Because of this, the plaster layer 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 - just mix the solution and pay attention to its "behavior". If the mixture sticks excessively to the oar, which interfered with it, then the solution turned out to be too greasy. If she does not stick at all, then she will be considered skinny. In the first case, to fill the situation, the filler is added, in the second - an astringent.

Construction Mixer Price

Construction mixer

Recipes

To prepare the working solution of the plaster as needed, it is important to know the recipes that are appropriate in each case. The main ones are presented in the table.

Table. Recipes for preparing stucco mortars.

Base component	Recipe
Cement	To prepare such a composition, cement and river washed, good quality sand are combined in a ratio of 1: 2.5-1: 3 for spraying, 1: 3-1: 4 for applying a primer layer, and in a ratio of 1: 2 for a finishing layer . The mixed components are diluted with regular water with constant stirring. You need to use the finished solution for an hour, so you should not dilute a lot of plaster at once. Exceeding this time limit entails a loss of material quality.
Lime	To create a mixture, sand is used as a filler and lime dough, as well as water. For spraying, combine 1 part of lime with 2.5-4 parts of sand, to create a primer layer - with 2-3 parts of sand, and for a mixture for finishing - with 1-2 parts of filler. Typically, this plaster resembles a viscous white dough. It freezes quite slowly, so you can immediately cook it in large quantities. But if you add a little gypsum to the mixture (5: 1), the solution will become stronger, but it will harden in just a few minutes. In this way, lime-gypsum plaster is obtained. To make the mixture stronger, you can add a little cement to the finished one (about 1/10 of the resulting volume).
Clay	This plaster is prepared according to a special recipe and a certain technology. First, the astringent component, that is, clay, is moistened with water and covered with a piece of fabric. When the clay swells, it is mixed with fine sawdust (1: 3) and clean water, pouring the latter until the mixture reaches a certain condition. The clay-based composition is not particularly strong, but its quality can be improved by adding a little cement (10 l of mortar - 1 l of cement). It turns out a cement-clay mortar. You can also create a gypsum mortar, but clay dough is used instead of clay. The main rule for preparing a clay-based mixture is to add so much filler to it that its amount is 3-5 times higher than the volumes of the binder component.
Cement and lime	By mixing 0.5 parts of the lime test and 2 parts of coarse sand with 1 part of Portland cement, this is the solution for wall plastering.
Lime and clay	In this case, mix 1: 1 lime and clay dough, adding 5 parts of sand to them. You can also mix 1 part clay, 3-5 parts sand and 0.2 parts lime.
Cement and clay	This solution is prepared equally regardless of the purpose of use. Cement, clay and sand are mixed in a ratio of 1: 4: 6.
Lime and gypsum	For 1 part of lime for spraying use 0.6-1 part of clay, 2-3 - of sand. For the primer layer - 2 parts of sand and 1.5 parts of gypsum, for the finishing layer do not use sand, but add 1-1.5 parts of gypsum.

There are such plasters which, in addition to the main functions, perform other tasks: increase heat and sound insulation, protect against harmful radiation, give the base refractory properties, and so on. It also refers to special ones, which is used for finishing surfaces exposed to increased exposure to moisture.

Construction dry mixes

Often, builders do not want to mess with the preparation of home-made mortars for plastering walls. It is much easier for them to buy a ready-made mixture based on Portland cement, which is called dry construction and has been actively marketed for many years. The composition of this tool includes various additives that make the finished plaster plastic, durable, more sticky relative to the working surface.

Advantages of dry building mixes:

• they are elastic, due to which they tolerate temperature extremes and changes in weather conditions;
• practically do not deform;
• do not need a reinforcing mesh;
• economical, as they allow you to prepare the right amount of solution without excess;
• diverse, which makes it possible to select a specific mixture for each type of work;
• "Breathe", letting in air, and do not collapse under the influence of moisture.

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

How to make plaster

At home, you can independently cook any type of mixture for plaster. Let's make the simplest one on a cement basis.

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

Attention! Detergent is used so that the mixture does not give strong shrinkage during drying.

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

Step 3   Pour the finished liquid evenly into sand laid in a wooden stretcher.

Step 4   Again with the help of a construction mixer we mix the sand and the soap mixture poured into it. The solution should reach a mushy state.

Attention! Add water gradually - you don’t need to pour the whole bucket at once, so as not to make the mixture too liquid.

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

Step 6   We mix the workpiece with a mixer and again add some water. Again, stir the mixture with a mixer. Using a spatula, remove dried pieces of mortar from the walls of the stretcher and knead them in a “common boiler”.

The mortar for plaster is ready, it can be used for decoration.

Advice! All materials that will be used to prepare the plaster, it is advisable to sift through a sieve. This procedure will achieve a more uniform consistency.

Video - Preparation of a plaster mortar

Rules for the preparation of mortar for plaster

To get the best quality wallcovering solution, 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 for many years in the applied form.

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

Mortar for wall plaster

What is the composition of the mortar for internal wall plaster?

When deciding which mortar for plastering surfaces is preferable to use, we will evaluate the characteristics of the ingredients used for bonding, and also consider the types of plaster compositions.

Types of binders and fillers

As a binder use:

Along with binders, various fillers are used.:

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

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

Types of plastering compounds

  Proportions of mortar for wall plaster

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

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

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 increased humidity is expected in the interior, this composition is also used for interior decoration;
• the introduction of clay, slaked lime and gypsum into the plaster composition allows you to use it with an increased concentration of moisture in the air. Such mixtures are mainly used for plastering dry heated and unheated rooms located inside the building;
• cement-gypsum plaster composition, in which clay is added, is used for interior decoration with normal moisture concentration. It is possible to use these binders for plastering the facade surfaces of buildings operated in dry climates.

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 steps for preparing various mixtures for plastering walls.

How to prepare a cement mortar for plastering walls

Let's consider how to dilute cement for plastering internal and front surfaces.

Procedure:

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

The finished mass must be used within half an hour, until solidification has begun. 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 lime-based wall plaster

In this embodiment, as an astringent, lime is used instead of cement. It is necessary to use slaked lime that does not contain foreign inclusions.

  Do-it-yourself mortar for plastering walls

The cooking process is quite simple.:

1. Prepare the 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. Re-filter the finished material through a sieve.
5. Add water with a thick consistency.

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

How to make a mortar for wall plaster using clay

Clay has traditionally been used for centuries to decorate walls indoors and outdoors. The cooking process requires a long time, since it is necessary to pre-soak dry material.

Sequencing:

1. Pour the cleaned dry clay with water.
2. Stir wet material.
3. Let her stand for a day.
4. Mash clay mass.
5. Add water to a viscous consistency and wipe through a sieve.
6. Pour sand in an amount exceeding the clay volume by 2–4 times.

  Clay mortar for plaster

The proportion of input sand is determined depending on the clay content. Modern technology provides the ability to add Portland cement, slaked lime and gypsum powder to increase the strength properties of the clay composition.

How to prepare plaster for interior work on the basis of gypsum

The accelerated drying of the gypsum composition requires quick preparation and rapid application. Gypsum-based mixtures are used to seal local irregularities and finish alignment of walls. It is possible to cook according to various recipes.

First option:

1. Mix chalk with gypsum in a 3: 1 ratio.
2. Mix the mixture with wood glue.

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

The second option is intended for processing chipboards or for leveling painted surfaces:

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

In connection with accelerated drying, it is necessary to prepare gypsum mass in small volumes.

The complex composition of the mixture for plastering walls

  Mixing the plaster

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

Cement mortar for stucco with lime

Prepare the cement-lime mixture in this order:

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

The consistency depends on the amount of milk of lime.

Another option is possible.:

1. Mix sand with lime dough.
2. Fill cement and mix.
3. Pour in water.

The viscosity required for work is determined by the amount of water added.

Lime mortar for plastering walls with the introduction of gypsum

  Lime mortar for plastering walls with the addition of gypsum

Gypsum-lime mixing is fast:

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

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

How to make a cement mortar for stucco with clay

The recipe provides for the introduction of cement in a volume of up to 20% of the total amount of clay. As a filler, fine river sand is used, which is mixed with clay before the introduction of Portland cement. This makes kneading easier and ensures the right consistency.

Clay-lime mortar for walls

Perform the lime-clay batch in the following order.:

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

This formulation provides an acceptable margin of safety.

Preparation of a stucco mortar based on clay and gypsum

  Clay and gypsum plaster

Use the following recipe for faster setting.:

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

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

Wall plaster mortar - basic requirements

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

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

If necessary, you can enter plasticizers.

What consistency should the stucco mixture have?

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 the mobility of the plaster.

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

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

To summarize

Possessing the technology of self-preparation of a stucco mixture, one can prepare on their own high-quality material for plastering walls made of various building materials. The strength characteristics and the degree of adhesion are affected by the quality and preparation of the raw materials used, respect for proportions, and the implementation of technological recommendations.

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

  Features of plastering - 3 layers

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

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

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

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

  What components are needed to prepare the mixture?

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

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

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

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

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

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

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

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

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

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

  Types of plaster mortars - different options

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

• astringent;
• filler;
• modifying additives.

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

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

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

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

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

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

• cement;
• lime;
• gypsum.

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

Cement binder   It is considered the most durable and waterproof.

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

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

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

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

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

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

Lime inhibits the development of microorganisms even decades after application.

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

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

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

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

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

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

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

Material	Plaster thickness, cm
Lime solution, l

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

Types of fillers that make up the stucco mortar

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Having decided to plaster the walls, you can purchase a ready-made dry mix in the store, which can easily turn into plaster after adding water. However, in this article we will go the other way and tell you about how to cook various stucco with your own hands.

Before starting the preparation of the mortar, pay attention to its correspondence to the base, on which the plaster will subsequently be applied.

• Cement and cement-lime mortars are used for the exterior walls of buildings, for facade work, as well as for rooms with a high level of humidity.
• Lime and lime-gypsum mortars are ideal for finishing wall and ceiling surfaces in rooms with a normal level of humidity.
• Mortar, the main binder in which clay acts, will be an excellent choice for plastering wooden and stone surfaces under the condition of a dry climate.

• All materials must be sieved through a sieve with mesh 3 × 3 (5 × 5) mm
• To prepare the solution, a box is used, the depth of which is 10-20 mm.
• Any solution should be thoroughly mixed until a homogeneous mass is obtained using a wooden oar 1 m long. The heterogeneity of the structure will prevent the high-quality setting of the finishing material from the base.
• After mixing the solution, make sure that it is oily by poking it with a paddle: a good composition should stick slightly to the paddle. If the solution sticks too much - add filler to reduce the fat content; if the solution does not stick at all - add weight to the binder.

Structure:   1 part cement and 2-3 parts sand

Theoretically, the proportions of the solution can be brought to 1: 6, however, the compositions in which more than 3 parts of sand account for 1 part of cement are characterized by low plasticity, and therefore are very laborious to work with.

1. Pour sand in a box to dilute the mixture.
2. Cover the sand with several layers of cement.
3. Mix dry ingredients thoroughly.
4. Add water gradually, constantly stirring the composition.
5. Finish adding water to a creamy mass.
6. If desired, you can add a little PVA glue or building gypsum to the solution - this will speed up the setting of the plaster. To slow down the setting, add a small amount of detergent to the drawer.

Please note that you need to use the solution within an hour after manufacture, so for large volumes of work it will be logical to mix the components in stages, in small portions. Long-term storage of the composition will lead to the loss of good strength characteristics.

Cement-lime mortar

Structure:   1 part cement, 3-5 parts sand, 0.7-1 part lime mortar

1. Take quicklime lime and place it in a non-plastic bucket.
2. Add warm water to the bucket (the liquid should completely cover the lime layer).
3. Quickly cover the bucket with a lid and press it down with a heavy load - when boiling, lime tends to "come off the coast."
4. Wait for the end of the chemical reaction and carefully strain the resulting turbid substance through cheesecloth.
5. After a day, you can use the mortar to create the plaster.
6. Next, prepare a dry mixture of sand and cement (1: 3 ratio).
7. Pour the milk of lime into the box with the dry mixture and mix until smooth.

Mortar

Structure:   1 part lime mortar and 3 parts sand

1. “Quench” lime with water to produce a lime mortar.
2. Add a little water and sand to the box with lime, which will facilitate the grinding of the composition.
3. Stir the mass, carefully getting rid of the lumps.
4. Throw the remaining sand in small portions while adding water.
5. The readiness of the composition will confirm the appearance of the solution: normal fat content and average density.

Lime mortars can only be used on the day of manufacture.

Gypsum-gypsum mortar

Structure:   1 part dry gypsum (alabaster) and 3 parts lime paste

1. Dilute the gypsum with water until a paste is obtained.
2. Add lime mortar to the gypsum and mix.

Use the solution immediately after manufacture, since it sets in record time - within 3-4 minutes, and complete hardening occurs within half an hour.

Clay solutions

You can prepare a clay solution using a technology similar to the creation of lime. However, keep in mind that the prepared clay solution is fragile, and therefore it is most often used with additives of gypsum, lime or cement.

• Clay gypsum mortar

Structure:   1 part clay dough (clay mixed with water until liquid), 0.25 parts of gypsum and 3-5 parts of sand.

• Clay cement mortar

Structure:   1 part clay dough, 0.2 parts cement, 3-5 parts sand.

• Clay-lime solution

Structure:   1 part clay dough, 0.3-0.5 parts of lime dough and 3-6 parts of sand.

To obtain all solutions, it is necessary to mix binders with each other, and then gradually add sand.

Please note that only specialists can produce solutions containing various chemical additives (for example, sodium nitrite or chlorinated water).

Preparation of plaster mortar (video):