Plaster is a good finishing material that has been used in construction technology for a long time.

The composition of the mixture for plaster includes the following components:

1. Binder. For example, lime, clay, cement or gypsum.
2. Filler. It can be slag, sawdust, shavings or sand.
3. Water.

The consistency of the mortar for plaster should be like dough. For plastering, both ordinary and decorative mixtures can be used.

There are a number of rules when choosing a solution for wall treatment:

• If the concrete or stone surface is under the constant influence of precipitation, it is necessary to choose solutions based on Portland slag cement or Portland cement.
• If the concrete or stone surface is not exposed to precipitation, then solutions should be chosen that include cement, lime, various types of lime-based binders.
• If you need to plaster a gypsum or wooden surface, you need to choose solutions that consist of lime, clay (gypsum binders).
• If internal plastering of the walls of the room with a high degree of humidity (above 60%) is supposed, the first layer of the plaster mixture should be applied from simple cement or cement-lime mortars. Such premises include a laundry room, a bathroom, a bathhouse.

Features of choosing a decorative solution for finishing

Decorative mixtures are used for plastering walls both outside and inside buildings. For the manufacture of a decorative mortar, the following are used as a binder: gypsum and lime (for colored interior decoration of a room), ordinary, white, colored Portland cements (for finishing facades, interior walls of a room). Different fractions of granite, dolomite, tuff, limestone and marble are also used. To make the finishing layer more brilliant, 1% mica or 10% crushed glass is added to the solution. And dyes in decorative mixtures for plaster are alkali-resistant and light-resistant pigments of artificial and natural origin. It can be chromium oxide, ocher, ultramarine, iron minium, etc.

Preparation of mortar for plastering: the main principles

Prepare a solution for plaster from carefully sifted materials. They are mixed until a homogeneous consistency. You can use one or more binders in one solution. It is important to check the fat content of the solution. Do this with a trowel. If the mixture is oily, then it will stick strongly. To reduce fat content, filler should be added. The use of fatty mixtures leads to the fact that after drying the layer will crack. In addition, there is an overexpenditure of the binder component. If the mortar is skinny, it will not stick. An astringent must be added to such a mixture. Skinny mixtures are fragile, it is difficult to work with them. Only a solution with a normal fat content is reliable, easy to use and has a long service life.

How is the treatment solution created?

The mixture for plaster is prepared in boxes with a depth of 15 cm or more. As for the volume of the box, it can be anything. Sand and cement must be mixed in certain proportions. The resulting dry mixture is introduced into the lime dough. First, the dough is diluted with water to the consistency of sour cream. Everything is thoroughly mixed. It is necessary to dilute the plaster, taking into account which layer it will be used for. As a rule, only three layers are applied to the surface of the wall. Layers are applied in stages. For all layers, a plaster mortar is used. They differ only in texture.

Types of solutions for plaster

There are six recipes for plaster mortars:

1. Lime paste. It is prepared from water and quicklime in a ratio of 3:1. Pour lime with water (warm). After the chemical reaction begins, water is added again. Stir. Close the container with the solution. And leave the solution for a day.
2. lime mixture. Prepare a solution of lime dough, sand. Proportion 1:1-5 (everything depends on the fat content of the dough). Sand and water are gradually added to the lime dough to the required density, stirring.
3. Lime-clay mixture. Prepared from clay dough, lime dough, sand in a ratio of 1: 0.4: 1-6 and water. The more sand, the stronger the solution will be. Clay is diluted with water. The consistency should be liquid Clay dough is mixed with lime. Stir. Add sand until the desired consistency is reached.
4. Lime-gypsum mortar. Made from lime mortar, gypsum in a ratio of 3:1 (or 4:1) and water. Gypsum is diluted with water. Gypsum mortar is added to the gypsum dough. Stir. Start using immediately.
5. cement mixture. Prepared from cement, sand in a ratio of 1:2 (1:3) and water. Mix cement and sand. Dilute the mixture with water to the desired consistency.
6. Cement-lime mixture. Prepared from cement, sand, lime paste in a ratio of 1: 3: 1 and water. Lime milk is diluted with water. The consistency is liquid. Prepare a mixture of sand, cement. And added to lime milk. Stir thoroughly.

Video

How to prepare a cement mortar: proportions for foundation, masonry, screed, plaster

Cement mortar is widely used in construction. It is used for laying stone and brick, interior wall decoration, pouring the foundation, and plastering. Naturally, depending on the application, this building material will have a different composition.

For example, for the construction of the foundation, in addition to sand and cement, crushed stone will also be required. The preparation of the mortar is a very important stage, because the strength of the masonry, the strength and durability of the structure under construction depend on the quality of the mixture.

1. Varieties of solutions
2. How to choose the right type of cement
3. DIY kneading technology

In order to properly mix the cement mortar, you need to know what grades exist, consistency requirements, mixing sequence and proportions of the base materials.

Usually use:

• sand;
• water;
• cement;
• less often: plasticizers and other additives.

Types of cement mixtures

Depending on the composition and purpose of use, the solution is divided into grades:

• M150 and M200 - for screeds;
• M50, M100, M150, M75, M200 and M125 - for masonry;
• M10, M50 and M25 - for plaster.

All varieties differ in quantitative sand content and proportions.

Changing the ratio of the main components allows the use of such a building material for various works.

The grade of the solution is an indicator of the strength of the structure built using it. The proportions of the ingredients depend, as a rule, on which brand of cement mortar is needed. Often, cooking instructions are printed on the packaging by the manufacturer.

Of course, you can order the finished mass of the desired brand (at present, dry ready-made mixtures for foundations, plasters or screeds are being sold, to which you just need to add the right amount of water).

But doing it yourself can save you money.

Rules for determining the desired grade of sand-cement mass

According to the technology, it is required that the grade of the mortar correspond to the grade of the material used (brick, blocks).

How to prepare a solution for plastering walls yourself

For example, if the masonry is being built from brick grade 100, then the cement mass should be M100. Subject to this rule, as a result, you will get a solid homogeneous brick structure.

In the event that the brand of the material used is high, for example 350, then it is not worth striving for a match, as this will significantly increase the cost of construction. The generally accepted proportions are 1 part (for example, a bucket) of cement and 3 of sand (1 to 3). When preparing concrete for pouring the foundation, 3-5 parts of crushed stone are added to this proportion.

On sale there is a huge range of different types of cement, differing in brand, manufacturer, properties and shelf life.

Portland cement is especially popular among professional builders, which is characterized by a high level of water resistance, frost resistance and strength. It hardens well in almost any weather.

Methods for preparing cement mixtures

When choosing this building material, be sure to pay attention to its shelf life, since the best mixture will be obtained if fresh cement is used.

Currently, the preparation of cement at home is carried out in two ways: mechanical and manual.

The first method involves the use of a concrete mixer.

Do-it-yourself kneading will require significant physical effort. In this case, all the necessary building materials are mixed with a bayonet shovel in a trough or an old bath.

To facilitate this process, water is first poured into the container, after which sand and cement are added. Then everything is stirred until smooth. At the very end, crushed stone is added and everything is mixed well again.

How to prepare a solution yourself

The foundation of the building must be reliable and durable, as it is the foundation of any building.

To fill the base of the building, the sand-cement mass is prepared in the classic ratio - 1 to 3. Usually crushed stone is added to it, although concrete is already obtained in the following ratio: 3 buckets of gravel (crushed stone) and sand, 1 bucket of Portland cement.

An important role is played by the ratio of water to components, which should be proportional.

Ideal is a solution in which water is 25%, but it is difficult to work with. Therefore, when kneading, water is added “by eye” at your discretion.

When mixing concrete, Portland cement grade M400 or M500 is used. For the foundation, the consistency of concrete should resemble thick sour cream. The preparation of a mass for leveling walls and plaster implies the following proportions of the components: 2 parts of sand and 1 part of cement.

To prepare a cement mortar for a conventional screed, the same components are used as for the preparation of concrete, only screenings are added instead of crushed stone.

The quantitative composition of the main components is taken in the ratio: Portland cement M400 or M500 - 1 bucket and 2 buckets of screenings and sand. To improve the plasticity index, it is recommended to add a little (50-100 g) detergent to the solution.

Remember that before mixing all materials should be sifted - this will improve the quality of the solution. The main thing is that there are no foreign impurities in the components. After that, the required amount of sand and cement is measured in doses in accordance with the proportions of the desired composition.

Similar articles

Before closing the walls must be covered layer of plaster.

In order for this coating to last for a long time, you need to know the correct proportion of mortar for plaster walls.

Plaster is a building mixture prepared in a certain way, which is evenly applied to the surface of the leveling wall.

Why plaster is installed on the wall:

• Increase wall power;
• Leveling the surface of the wall;
• Filling cracks;
• Increase heat and sound insulation;
• Waterproofing that does not interfere with air access.

To prepare any wall covering solution, we need three components:

• Binder (lime, cement, clay, gypsum or mixtures thereof);
• Filler, usually sand;
• Pure water.

How to use plaster?

It can be used in three steps: spraying, filling and finishing.

Mortar for gypsum walls - how to prepare a mixture with your own hands?

For each of these levels, the components of the components must be slightly modified.

Less binders should be added for spraying. Add some binder to the coating. And in the last, ending - the maximum amount of binder.

If the treatment is carried out at one stage, the solution must be prepared strictly in relation to the ratio.

When you're ready, you can split into:

Bold - Holds tools strongly.

Fixed with filler and water.

Normal - the tool remains a thin layer of material.

Skinny - there is practically no mixture on the instrument.

Usually a binder needs to be added.

Sand cement

Most popular for exterior wall. Sometimes it is used for interior decoration. The most persistent.

To do this, you must cut the sand.

It is advisable to use white sand, and sand with a yellowish tinge will make the coating strong enough. Sand is mixed with cement in a 4:1 ratio if M400 cement is used.

The situation must be strictly observed, otherwise the plaster will be unstable.

If you are using other brands of cement, the ratio will be different.

The cement mortar begins to harden after about 45 minutes.

lime

This is easy work. It is made from a mixture of lime and sand. You can mix it yourself or buy a prepared mix.

One of the most popular solutions for interior decoration.

Lime must be used for cooking in limestone.

This is a rather lengthy process, so it is better to buy already prepared carbonated lemon in the dough.

The preparation of the plaster mixture is quite simple: one part of dried lime is mixed with three parts of sand.

Mix and gradually introduce water, bring it to the desired state.

The pre-sand must be screened to remove large chunks and stones.

The drying time of this solution is up to 12 hours.

Lime-gypsum

To prepare it, consider the correct proportions of the components.

If you add a lot of plaster - the mixture quickly hardens.

If the plaster is small, it will dry for a long time. Prepared in the proportion of the solution, well used and withdrawn.

Prepare it with one part dipped limestone, one part stucco and 3 parts white sand.

All components must be cleaned of large particles and mixed with water in small pieces.

Drying time is very short.

After 5 minutes, the mortar will be adjusted with the addition of plaster, so it is advisable to prepare it in small quantities so that the time can be applied to the wall.

clay

It is made of clay, sand and water.

This coating requires a special coating. Suitable for interior and exterior decoration.

In the second case, under the influence of natural factors, he can wait. Cement, gypsum, lime can be added to add power.

Also, if you want to change the properties, sometimes add sawdust, straw, horse manure, manure.

There are no exact proportions for preparing a mixture of clay.

Because the clay in different areas has a different composition and density.

Conditions for mixing clay and sand can vary from 1:2 to 1:5.

Before you start preparing the mortar, mix a small amount of sand and clay to determine their required proportions.

How to determine whether solutions are ready or not? It is like well-kneaded clay and similar very thick sour cream.

You can turn it around and crush it with your finger up to a centimeter in thickness.

The resulting "pancake" should be full with no cracks around the edges.

When you decide on a relationship, you need to:

• Soak the clay for one day and mix it;
• Formation of the formed composition;
• Remove sand and saw if you are using them;
• Add a suitable amount of sand and fillers, mix thoroughly.

Clay plaster dries for a long time. Coating thickness of 1 cm under suitable conditions dried for about 2 days.

It may take up to 2 months for complete drying.

Which one is better?

It all depends on the area to be treated. Limestone mortar is used to prevent brick and concrete surfaces in rooms with normal humidity.

Cement - used outside buildings or in areas with high humidity, and is also used as a base for decorative tiles.

Clay - used in dry climates to work wood and stone.

Dry mixes

All of the above solutions must be prepared independently, known and observed.

However, during this time a large number of special mixtures have been created in which the required proportions have already been saved.

In order to maintain the composition well, it is necessary to prepare the substrate for applying the plaster. For this you need:

• Remove traces of old plaster;
• Remove dust by washing with water;
• Move the surface;
• Do not plaster at temperatures below +4 and above +24 degrees.

See article article:

Wall plaster mortar is very easy to prepare from such mixtures, you need to add the amount of water indicated on the package and mix thoroughly.

On the other hand, the correct proportions of wall plaster mortar do not guarantee that the coating will not burst or fall off.

Mortar for plaster

Plastering work. Shepelev.A.M.

Cement, gypsum and lime are the main binders used in the preparation of plaster mortars and dry mixes. When preparing complex plaster mortars consisting of two binders and aggregate (sand), you should know that lime can be mixed with either gypsum or cement. Gypsum should not be mixed with cement.

Types of plaster solutions

Cement is obtained by grinding clinker and gypsum, while grinding, various mineral additives are added up to 15% (pyrite cinders, flue dust, bauxites, sands, flasks, tripoli), some to improve properties, others to reduce cost.

Clinker - obtained by firing limestone and clay. Cement is a hydraulic binder and has the ability to gain strength in wet conditions. Positive aspects: durability, strength, not afraid of dampness.

Negative sides: exacting to adhere to the technology of applying layers and preparing the base, otherwise the plaster will crack. For painting, puttying is required, it absorbs paint. (for the façade and wet rooms, putty based on white cement; for dry rooms, based on building gypsum.)

Building gypsum is used as an air binder, as a basis for the manufacture of dry building mixtures (putties, plasters). It is used in construction for plastering walls and ceilings in buildings with a relative humidity of not more than 90%.

lime mortars.

Lime mortars are used for plastering walls and ceilings. When plastering wet rooms, it is recommended to use cement-lime mortars.

Preparation and application of plaster solutions.

Lime plaster mortars used for plastering stone walls and ceilings with the exception of cornices, plinths, parapets.

In humid rooms, these solutions are not used. These solutions harden faster than clay ones, however, for plastering they also require a large front of work, especially when they are plastering wooden and other surfaces that poorly absorb water from the solution. On brick surfaces, due to the rapid absorption of moisture from the solution, hardening occurs much faster and the scope of work decreases accordingly. The hardening of lime mortars is easy to determine by how white they are.

Lime mortars have a low strength - 4 kgf / cm. They seize slowly, so they can be prepared in large portions and stored for two or three or more days. However, from long-term storage, they lose their plasticity and an astringent must be added to them. Prepare these solutions as follows. The (liquid) or put (thick) lime dough filtered through a sieve is poured into the box.

Add the sifted sand in small portions, mix everything. Sand is added until a homogeneous solution of the required fat content is obtained. For uniformity, the solution is filtered through a sieve. The thick solution is diluted with water. To prepare a lime-gypsum mortar, the lime mortar is made thicker.

Lime-gypsum plaster mortars. Lime-gypsum mortars are used to plaster wooden surfaces of non-moistened rooms, as well as stone, fibrolite, reed and straw surfaces.

Eaves are well drawn out of this solution. Lime-gypsum mortars set quickly, so when working with them, a large front of work is not required.
Lime-gypsum mortars (plants) are prepared in small portions (no more than 5 liters) so that they can be used in business within a few minutes. The setting solution must not be stirred, as in this case it loses its ability to harden and does not acquire strength.

To prepare a portion of the solution, water is poured into the solution box, gypsum is poured into it with a thin layer and everything is quickly mixed until a gypsum creamy dough is formed. Then lime mortar is added there, mixed again quickly and used immediately. This operation takes no more than 4-5 minutes.

Cement-lime plaster mortars (mixed). These solutions are used for plastering external walls, wetted parts of buildings, as well as baths, wet rooms, plinths, etc.

These solutions set slowly. They are applied in thin layers so they can be prepared in large portions. Cement-lime mortars are used for an hour, that is, before the cement begins to set. These solutions are more plastic than cement ones, they are more convenient to work with, they are easily applied in a thin layer.

Cement-Lime mortars come in different compositions. 1:2:8, 1:2:9, 1:2:11. 1:312, 1:3:15 (volume parts). In the first place is cement, in the second is lime paste, in the third is sand.

The brand of mortar depends on the brand of cement. These solutions can be prepared in different ways. In one case, a dry mixture is first prepared from cement and sand, I measure the required amount of lime paste and water, everything is mixed, milk of lime is obtained, which is filtered through a sieve, and the cement mixture is closed on this milk of lime.

In another case, lime mortar is prepared from lime paste and sand. Cement is added to this solution and everything is mixed. If necessary, add water. You can also mix cement with water, add the resulting cement milk to the lime mortar and mix everything until completely homogeneous.

Cement plasters. Cement mortars are used in damp places.

They plaster the lower parts of foundations in a humid environment, plinths, exterior walls of buildings, they are used to install an insulating layer with the addition of waterproof additives. Cement mortars are strong, but hard, slowly setting. To perform work with cement mortars.

A significant amount of work is needed. Cement mortars are used no later than one hour after preparation. The compositions of cement plaster mortars are used from 1:1 to 1:6, t.

That is, for one volume part of cement, from 1 to 6 volume parts of sand are taken. Solutions in a ratio of 1:4 or more are quite hard and inconvenient to apply. In plastering, mortar compositions up to 1: 3 are most often used. They are more plastic, well applied and leveled, but require more cement. These solutions are prepared in such a way that cement and sand are measured in the required doses, mixed and sifted through a sieve. The prepared dry mixture is closed with water.

Solutions on ground quicklime-boiling. These solutions are used for the same purposes as solutions on lime test.

The prepared solution is kept for 30 - 40 minutes and only after that it is applied to the surface - this facilitates its leveling and grouting.

Clay plaster solutions. Clay mortars are used for plastering dry rooms. Prepare them like this. Clay is placed in a container. Pour water into it, knead the clay and leave it for a day. A day later, knead again and mix until smooth, adding water to a creamy consistency.

After that, the solution is filtered through a sieve. Sand is added to the resulting clay mass in small portions and mixed until smooth. The amount of sand depends on the fat content of the clay. For strength, lime dough is added to clay solutions. These solutions can be used for several days. In case of thickening, water is added to them and everything is mixed.

Each subsequent layer of the solution is applied only to the sufficiently hardened previous one. Clay mortars are applied to structures made of stone, brick, wood, adobe in thin layers. These solutions harden slowly. In order for the applied layers of the solution to have time to thicken and dry before applying the next layers, a large front of work is needed.

Uch.posoble Plastering. Shepelev.A.M.

Plastering work.

Shepelev.A.M

1. Textbook title. Plastering work. Author. Shepelev.A.M.
2. Classification and main parts of buildings.
3. Finishing and construction work.
4. Occupational safety and fire prevention measures in construction.
5. Requirements for scaffolding and ladders.
6. Scaffolding.
7. Cradles, scaffolds, ladders.
8. Plastering tools.
9. Plastering inventory.
10. Preparation of wall surfaces intended for plastering.
11. Sequence of plastering of various buildings
12. Stuffing a metal mesh under thick layers of plaster.
13. Plastering of wooden walls.

    Plastering preparation.

14. Wall plastering. Preparation of stone, brick and concrete surfaces.
15. Preparation of adobe, fibrolite, reed and straw surfaces.
16. Preparation of joints, channels of reinforced concrete slabs, steel beams for plastering.
17. Arrangement of mesh-reinforced structures for plastering.
18. Safety engineering.

    Plastering work.

19. Safety precautions when carrying out plastering work.
20. Organization of plastering works.
21. Throwing plaster.

    Applying plaster.

22. Plaster. Preparation and application of plaster solutions.
23. Application of simple and improved plaster.
24. Making high quality plaster
25. Covering, grouting, smoothing plaster.
26. Plastering of husks, mustache and chamfers.
27. Plastering of internal and external slopes.
28. Sgraffito plaster.
29. Requirements for the quality of various types of plaster.
30. plaster defects.

    Cracks, peeling, dutiki.

31. Waterproof plaster mortars
32. Repair work on facades
33. Repair of surfaces trimmed with sheathing sheets.

Stucco is a classic finish that allows you to level wall gratings in buildings and properly prepare for subsequent finishing.

Plaster is used both inside and outside. In order for the solution to remain durable and time-consuming, it is important to respect the proportions of building materials, follow the recipe and achieve the best result.

Classification of gypsum mixtures

Each potting mixture used for gypsum walls consists of two main components:

• binder material;
• filler.

The cement component can be provided without clay, lime, sand and cement.

Given the nature of the future work and the area on which the mixture is used, priority should be given to these or other "ingredients". For example, sand is used for plaster walls, which act as a great aggregate, making the plane more durable and won't burst over time.

Plastering takes place:

1. Cement and with the addition of lime - the name speaks for itself, the cement component plays the role of a base.

   If you want to improve and process the facade of wall structures, then this is the best way to prepare the mass.

   Types of plaster mortars

   The cement additive allows the material to be used at the end of a room where humidity levels rise - perhaps bathrooms, showers and toilets.

2. It can also be without cement. All that is needed is to provide the necessary ratio of lime and gypsum, lime and clay.

   This mass allows you to process the surface of the walls, for which there was no systematic moistening, so you can work in dry rooms.

3. Clay is a unique material that, together with cement, creates a suitable mixture for indoor walls, but only in places where the moisture content does not exceed the normative value.

   Therefore, clays can be used in regions where a dry and even hot climate prevails.

The ratio of ingredients in the render mix

Most often, for building mortars, builders use a mortar with the addition of cement.

The optimal proportions of the combination of cement and sand are determined in the ratio:

1. Cement and sand are mixed together, taking into account parts 1: 3, 1: 4, water is poured into the container.

   All ready-made solution should be used in the next hour, when it becomes inadequate and of poor quality.

2. If, in addition to cement, limes are mixed in bulk, it is better to take Portland cement on a package marked M400 or M500, as well as on bay lime paste and 2 parts of sand without contamination.

Check the degree of sand contamination with sediment and clay: take a plastic bottle, pour out water, add grains of sand, shake well and observe the color change of the substance.

If it has become a little cloudy, this sand can be used, if the liquid has lost transparency - the material is not suitable.

The mixture interferes with modern materials

Today, dry plasters are available as renders that provide a high quality wall.

What is the secret of the unique formula for the adhesion of modern plaster surface mortar? It includes the right parts of polymer materials that improve the quality of the cement so it becomes more durable.

See also: floor mortar

In addition, experts recognize a number of important advantages of dry mixes:

• do not require work using a reinforcing mesh, which significantly reduces the cost of gypsum for wall decoration;
• the mass acquires elasticity and helps to achieve a minimal response to harsh climatic conditions, such as an increase and decrease in temperature, humidity (dry gypsum mortar, in which the components of the components correspond to the technologies, can change shape, but not deform);
• wet surfaces acquire a porous structure through which free air penetrates.

When buying dry gypsum for wall treatment, always pay attention to the manufacturer, the more he hears, the better it will be.

As a rule, a well-known brand is not only about the profit that a company receives from the sale of products, but also about maintaining its name, so it is not advisable to avoid measurement errors and inaccuracies, the coefficients are supported up to thousands,

But you must understand that such a luxury for the average home owner comes at a high financial cost.

The latest render blends indicate the readiness of the blends as needed, and the rest of the material can be left later and not degraded. Of course, the use of such a building product is very convenient, by the way, this approach saves nerves and money.

How to mix with cement mix

Let's go over some important rules to keep in mind to get the best out of walls:

1. If the plaster is done using cement and sand, there is no need to be surprised when the mass is slightly leveled or reacts to temperature fluctuations.

   A dry mix will avoid such problems by adding sand from different fractions and compacting the structure, thereby reducing the likelihood of cracks and chips.

2. When do cracks occur? If the correct dimensions are kept, the cause may be hidden in the wrong material layout sequence.
3. Don't ignore the drying time, don't be careful and want to speed up the process with fans and special types of hair dryers.

   The cement mortar is unevenly attached.

4. Before the next finishing work, complete the curing period for 10-15 days. If the room temperature leaves much to be desired, and the humidity indicates excessive values, you need to wait a few more days.

How to make a plaster mixture

Today, you can choose any ready-made plaster mixture, but for plastering work, you can prepare the solution yourself.

The most popular is lime mortar with various fillers such as cement and clay.

Materials and tools: cement; water; construction mixer or electric drill; lime dough; clay; sand; ready modified dry mix; gypsum.

Step one

To get a lime mortar for wall plastering, dilute one part of lime dough and three parts of sand with water to the consistency of oil, mix this mass with a construction mixer, and then gradually add 1 kilogram of dry cement or gypsum during the whipping process.

step two

The mixture must be applied with a spatula immediately after preparation. Do not make the solution more than you can apply within 30 - 40 minutes. Re-stir the plaster mixture with a construction mixer every 10 minutes.

When using gypsum instead of cement, mixing takes about 2 minutes, and application should take no more than 6 to 8 minutes. If you do not use the mixture before this time, it will harden and you will not be able to carry out plaster work.

Step Three

To prepare a clay mixture, thoroughly mix 1 part oily clay and 3 parts sand.

Gradually add water and stir until a thick homogeneous mass is obtained, after which add 1 kilogram of cement. Carry out the calculation of cement for 10 liters of mortar.

How to make mortar for plaster

If you want to make the solution more durable, instead of cement, add 1 kilogram of gypsum. Apply the mixture with the addition of cement within 1 hour, with the addition of gypsum - 15 minutes.

Step Four

To prepare a cement-lime mortar, mix 1 part of M400-500 cement, 0.2-0.3 parts of lime paste and 3 parts of sand thoroughly with water.

You can use milk of lime instead of lime paste to dilute a mixture of cement and sand.

Step five

Compared to self-prepared stucco mixes, ready-made dry mixes are created using advanced technology, which makes them stronger, more flexible and more mobile.

Such mixtures can be used immediately by adding the right amount of water and mixing the mortar with a construction mixer or a construction drill.

The composition of the plaster is known, if not to everyone, then to very many. It would seem that there is nothing unusual in it, and its components are not in short supply. However, the preparation of a plaster mortar requires care and strict adherence to proportions, otherwise the mortar simply will not lie on the walls or after a short time it will begin to crack and peel off the surface. There are several types of plaster mixtures, each of which is used in certain works. The composition of the mortar for plastering walls inside the room differs from that necessary to create a protective layer on the outer walls.

What is plaster

Plaster is a rather rough facing material that performs protective functions in relation to the surfaces of facade and interior walls. For the preparation of a plaster mortar, various components and components, tools and technologies are used, but they strive to achieve one goal. This goal is to create a high-quality, durable, reliable coating on the walls of the building.

Before preparing a solution for plastering walls with your own hands, you will need to stock up:

1. The basis, which is most often used cement. It is also called a binder, which ensures the strength of the finished mixture.
2. The filler, with the help of which the volume of the solution is significantly increased, there is a strong bond between the particles of the mixture.
3. Liquid (of course water), which, when preparing a solution for plaster, is added in a strictly defined volume. Excess, as well as lack of moisture in the solution, will lead to its cracking and rapid destruction.

There are several types of compositions designed for plastering walls. Their main difference is the material used as a base, but, in addition, each of these compounds is created to create a coating on certain surfaces.

Novice builders often think that preparing a mortar for plaster is simply mixing cement, sand and water, but to create a high-quality mixture and a really durable coating on the walls, you must strictly observe the proportions and take into account the possibility of introducing some additional components into the mortar.

So, for example, in some cases lime is added, despite the fact that this substance is not durable and, when dried, quickly crumbles and crumbles. As a constituent mortar for plastering walls, the proportions of which indicate that it is not necessary to add a certain amount of this white powder, lime is used as a means to increase the plasticity of the mortar. Gypsum quickly hardens and contributes to the rapid hardening of plaster mixtures.

Clay is a component without which it is impossible to imagine the process of plastering furnaces. Its main distinguishing feature is a set of strength after firing.

The main condition is precisely observed proportions for plaster. But no less important is the correct choice of the basis of the mixture and the various components, depending on the operating conditions of the created coating.

cement mortar

Cement mortar for plaster is the most in demand and popular in the performance of various works related to the rough finishing of the walls of the building. Its main advantage is a high level of strength. To obtain a high-quality mixture, it is important to know not only how to dilute cement for plaster, but also what components and in what quantities should be present in the solution.

How to make mortar for plaster from cement? You will need to prepare the exact amount of each of the required components. First of all, we are talking directly about cement. Depending on what qualities the prepared solution should have, choose the brand of cement. For plastering the exterior walls of a building, cement grade M 200 - M 300 is most often used. A mixture prepared on the basis of such a binder will have a high level of strength and is suitable for creating a rough finishing coating on the facade of the building.

Properly observed proportions of cement mortar for plaster are of great importance:

• cement brand M 300 - 1 part;
• fine seeded sand - 3 parts;
• water is added in such a volume that the resulting mixture resembles thick sour cream.

The amount of water depends on the moisture content of the sand, so the exact number of buckets used in the preparation of the cement-sand mixture cannot be specified.

The solution for plastering walls, consisting of cement, sand and water, has only one binder (cement) in its composition, and therefore belongs to the number of simple ones. Complex or multicomponent mixtures are called mixtures, which include two or more binder components. An important condition for the preparation of a high-quality plastering solution is the refusal to add any components during the mixing process.

Before you make a cement plaster mortar, you will need to prepare a container in which you can freely mix all the components. First, cement and sand are poured there, both components are mixed and filled with water, introducing it into the solution gradually and achieving the desired consistency of the mixture.

An important characteristic is the fat content of the solution, which can be determined by how the composition behaves on the trowel:

• Sticks to the tool - high fat content and to create a high-quality coating, you need to add a small amount of filler to the solution.
• Does not linger on the trowel - the solution is thin, you can correct the situation by adding a binder.

The ratio of filler and binder is correct if, after manual mixing, a thin layer of mortar remains on the trowel.

Lime

The composition of lime mortar for plaster is similar in proportion to cement-based mortar. To prepare the mixture, you will need directly lime and sand in a ratio of 1: 3.

Before you make lime mortar for plaster, you need to separately prepare lime dough in advance. Lime in its pure form is not added to the solution.

Cement-lime mortar for plaster for 10 parts of cement, add 4 parts of lime and 30 (maybe 50) parts of sand. This is the highest quality composition for applying the first layer of plaster (spray). For the second layer, cement and lime dough are taken in equal parts, and for the third layer, lime is 1.5 times more than cement.

The time for complete solidification of such a mixture due to the addition of lime dough increases by two days, but at the same time the level of strength of the finished coating also increases. Before making a solution for plastering walls with the addition of quicklime to its composition, the powder must be poured with water and left for at least 14 days. The extinguishing process is quite lengthy, and non-compliance with the technology leads to the creation of a poor-quality mixture, which, after complete drying, begins to crack and fall off the surface.

The process of preparing the solution requires first of all to mix the dry components, then add the lime paste and only after that introduce water, constantly mixing all the components of the solution until a homogeneous mixture is obtained. There should be no lumps in the resulting solution.

The preparation of lime mortar for plastering begins with the addition of a small amount of sand to the finished lime paste. The amount of clean sifted sand should be at least 3 parts per 1 part of slaked lime. After thoroughly mixing the components, proceed to the gradual addition of water.

Gypsum and clay plaster

Gypsum mortar for plaster is not particularly durable, it does not tolerate the destructive effect of moisture and therefore is usually used when working indoors. You can increase the level of its strength by adding a little cement to the solution. Before preparing plaster based on gypsum, the content of sand and cement in the solution is calculated.

Gypsum plaster quickly hardens on the treated surface, so professionals or people with certain experience and skills in working with such compositions work with this solution.

Before starting work, the entire surface of the wall is divided into sections, the area of ​​\u200b\u200beach of which does not exceed 1 m 2.

This action is necessary because this mixture for plastering has a minimum drying time. Starting to prepare the solution, sand and lime or cement are first mixed, and then building gypsum (alabaster) is mixed in a separate container with plenty of water. Now gradually add the gypsum mixture to the cement with sand or lime paste mixed with sand.

Clay plaster is prepared on the basis of alumina, which is pre-soaked in water. The required amount of material is poured with water so that it completely covers the alumina and leave for at least 5-6 hours to swell. The softened clay is thoroughly mixed and three times as much sand is added to it. The main condition is the gradual addition of all components of the mixture and constant thorough mixing of the composition. If a pure clay mortar is used for plastering ovens, then after the final mixing it can be immediately applied to the surface.

To work on the walls of adobe houses, clay plaster is used with the addition of lime, building gypsum or cement:

• lime dough - 1 part;
• soft clay - 2 parts;
• sifted sand - 6 parts.

With this solution, you can plaster the inner surface of the walls. In the event that plastering will be carried out outside the building, mix:

• 10 kg of cement;
• 2 kg of clay;
• 30 kg of clean sand.

Water is added gradually, watching the consistency of the mixture. When using building plaster, you need to be very careful. Clay plaster with the addition of alabaster hardens after 5 minutes, and dries completely after half an hour. That is why the solution is prepared in small portions, applied to small areas of the surface, alabaster is added no more than ¼ of the amount of clay. You can get acquainted with the intricacies of the process of preparing a solution for plaster with your own hands by watching the video.

It is not so difficult to prepare a mortar for plaster with your own hands, but we must not forget about the need to comply with all the rules of existing standards regarding the materials used. Do not violate the sequence of work and established proportions. Only in this case, all the manipulations performed will achieve a positive result.

The most reliable way with which you can qualitatively level the walls is plastering. Plaster allows you to prepare the base of the outer and inner walls for finishing. Previously, to prepare a solution for plastering walls with your own hands, classic ingredients were used mixed with water in the correct proportion. It was only cement and sand.

The modern market for building and finishing materials is full of ready-made mixtures that only need to be diluted with water. However, the rules for mixing the mortar will vary depending on the composition of the plaster. How do cement, clay and lime mortars differ from each other, and how to mix them correctly?

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The composition of the plaster

Each plaster solution has its own components, mixed in various proportions:

• clay and sand in a ratio of 1 to 2 (5) - the number of shares of sand depends on how viscous the clay turned out;
• a solution consisting of three components - clay, lime and sand - is mixed in a ratio of 1: 0.4: 4;
• clay, cement and sand plaster is mixed in a ratio of 1:0.3:4.

All of the listed types of plasters are mixed with water, the amount of liquid directly depends on what viscosity you need.

What is required for work

To mix different plaster compositions, you will need one or more binders (cement, lime, clay or gypsum), filler (most often this role is played by sand) and water. When mixing all the components, you should be guided by the exact ratio of the proportions of the composition. However, this is not the only thing to consider: the quality of the plaster is affected by such a concept as fat content. Most often this applies to lime and clay plasters.

In this case, the concept of "fat content" is in no way connected with its literal meaning: it is a parameter by which the amount of the binder component is determined - sufficient or excessive. By fat content, plaster compositions are divided into three types - fatty, normal and skinny.

• The disadvantage of greasy plaster is that it shrinks too much when it dries, which leads to cracks in the surface.
• Too lean mortar is also covered with cracks, but for a different reason - it does not adhere well to the surface and gradually begins to move away from the base.

It is difficult to determine the level of fat content of plaster by eye; this requires some experience. When kneading the composition, check how strongly the plaster sticks to the tool. The stronger the solution sticks, the greasy the plaster, but skinny plaster, on the contrary, will stick very poorly or not at all.

cement mortar

To properly prepare the plaster composition from cement, you need to perform several stages of work:

1. First of all, the sand is dried and sifted until there is not a single lump left in it. Important: reddish sand should not be added to the plaster, as it is of poor quality. If you do not want to bother with sifting, you can use quarry sand, it is already clean and crumbly.
2. The second and last step is mixing. Pour cement and sand in a ratio of 1 to 4 into a container of a suitable size and mix thoroughly. To avoid the appearance of lumps, pour water into the composition gradually. However, such plaster will be extremely difficult to stir on your own if you need too much mortar. For such volumes, you will have to rent a concrete mixer.
   
   Important: to obtain high quality plaster, you need to use cement not lower than M400. With the use of cheaper and lower quality cement, the walls will simply crumble.

   Lime mortar for walls

   
   

   Making such a plaster is somewhat more difficult than a classic cement mortar. Lime plaster hardens much more slowly, so you have to resort to some tricks.
   Important: only slaked lime is suitable for the preparation of lime mortar.
   Stages of work:

   1. Grind the lime so that in the end there is a homogeneous mass without lumps.
   2. Pour sand in proportions of 3 to 1 in relation to lime.
   3. Thoroughly mix the dry plaster and begin to gradually pour in water until a solution of the desired density is obtained. Ready plaster should not be stored for longer than a day - it will be unsuitable for further use.
   4. In order for lime plaster to harden faster and have better adhesion, a little gypsum should be added to it. But in this case, it is better to stir the composition in small quantities, since it will harden very quickly - almost instantly after application.

   Important: do not overdo it with the amount of water. Too much liquid will only worsen the quality of the plaster.

   Clay plaster mortar

   
   

   No less than lime and cement, natural clay is also used. The main thing is not to buy liquid clay for plastering, because it will eventually slide down from the wall. To make a solution of high quality, you will need a large number of ingredients - clay, sand, cement and lime. Stages of preparation:

   1. Soak the clay in water for 6 hours and add new water regularly as soon as you see that the top layer has begun to dry out. You should get clay of medium density.
   2. Pour pre-sifted or quarry sand in a ratio of 2 to 1. Sometimes the amount of sand needs to be increased to four parts.
   3. To strengthen the mortar, add 0.2 parts of cement and mix well.

   Not all plaster solutions are suitable for outdoor use, some are used only for interior wall decoration. The technology of using mixtures depends on their composition.

   Where is plaster used?

   
   

   Depending on the climate, the level of humidity, the place where the plaster is applied, different solutions are used:

   • Lime and lime-gypsum plasters are best suited for leveling indoor surfaces. Such walls turn out to be literally "breathing" - depending on the change in the level of humidity, they either store moisture or give it back. As a result, the microclimate in the room is constantly regulated and maintained in the normal range.
   • Cement-sand plaster is used for exterior finishing work, and is also used in rooms with too high humidity - in the kitchen, bathroom, bath, etc. Such plaster not only levels the surface of the outer walls, but also holds them together, making them stronger . Cement-sand mortars are used for finishing stone fences and garages.
   • Pure lime plaster is well suited for processing window slopes, it is much more effective than cement plaster, since it has better thermal insulation parameters. For example: the thermal conductivity of lime plaster and cement plaster is 0.86 and 1.3, respectively.
   • Clay plaster is often used to decorate stoves, pipes and fireplaces. At the same time, the nearest space around the furnace is plastered with a clay-sand composition, and the thermal surfaces are plastered with a solution of clay and lime.

   Surface preparation for plastering

   
   

   Plaster of any type should be applied only on a previously prepared base, otherwise the results of the work will not please you - the plaster will fall off the wall or ceiling along with the decorative coating.

   • In brickwork, all protrusions from the joints must be removed, and the bricks themselves must be completely cleaned of dust, dirt and cement residues.
   • Before starting work, notches must be applied to the surface of building blocks.
   • If earlier there was already plaster on the base, it must be completely beaten off or only the top layer should be removed - depending on the condition of the coating.

   Calculation of plaster consumption

   Before starting work, it is important to know exactly how much plaster is needed - this will help save money by avoiding overspending of the material. There are two main factors that are important to consider when calculating the volume of plaster:

   • Curved walls. If it so happened that the walls in the same room are different in length and width (and this is not uncommon, for example, in panel houses), they must be leveled, which will require a much larger amount of plaster. It will also be necessary to increase the volume of the mixture if there is a need to close cracks and potholes.
   • The composition of the plaster itself. Since different mixtures have their own consistency, the consumption per 1 sq. meters will be different.

   Method for calculating plaster

   First of all, you need to determine the required coating thickness. You should first prepare the base by removing all parts that are loose or crumble. When the wall is ready, use a laser level and determine the level by placing beacons around the perimeter of the room. If there is no laser, use a weight (an ordinary washer will do) on a strong thread. Next, measure the degree of deviation from the resulting line at 4 points, add the resulting data and divide by 4.

   
   
   Standard plaster mixes are based on a layer of 1 cm per 1 sq. meter. It is enough to calculate the area of ​​\u200b\u200bthe walls that require plastering. Multiply the resulting dimensions by the average thickness of the plaster calculated earlier. At the same time, always buy mixtures with a small margin, since the actual consumption of plaster may differ from what you counted. Get a couple of packs more, but no more.
   Some features of plaster mixtures:

   1. The lime composition is warmer and practically not susceptible to the appearance of mold and fungi.
   2. Cement plasters are moisture resistant and have great strength.
   3. Gypsum in the composition of lime mortars increases their strength and quality of adhesion to the surface, but greatly reduces the time of use.
   4. Clay plaster mortars are the least durable of all, but they perfectly withstand very high temperatures.

   When carrying out finishing work, outdoor or indoor, be guided by the choice of plaster based on the highest priority qualities. Then the plaster will last a very long time, and over time there will be no surprises in the form of cracks or crumbling 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 inside or outside the premises.

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

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

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

• astringent;
• filler;
• modifying additives.

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

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

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

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

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

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

• cement;
• lime;
• gypsum.

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

cement binder considered the most durable and water resistant.

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

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

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

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

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

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

Lime prevents the development of microorganisms even decades after application.

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

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

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

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

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

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

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

Material	Plaster thickness, cm
Lime mortar, l

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

Types of fillers included in the mortar for plaster

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

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

For ordinary plaster, as a rule, it is sand, for a special one, the range of fillers is much wider, for decorative, ground rocks of semi-precious stones are used. In addition, they may contain impurities; the grains themselves can be of various shapes and have different densities and much more. Consider the types of fillers for plaster mortars, their list is as follows:

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

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

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

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

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

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

Quartz sand and diabase flour are fillers for acid-resistant plasters. Metal shavings and dust are used as fillers for impact-resistant plaster.

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

Sand for decorative plasters is the most varied. It can be a mineral filler with a fraction of 1.5-4 mm for modern so-called "facade" decorative plasters.

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

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

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

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

They can be of natural origin (sedimentary and volcanic) and artificial. Natural sedimentary ones are diatomites, tripoli, flasks, gliezhs; natural volcanic - trails, tuffs, ash, pumice; artificial - silica waste, burnt clay fuel waste.

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

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

The mode of their action is mainly reduced to the interaction with the binder (cement) and the strengthening of certain of its properties.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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Do-it-yourself mortar for plastering walls: proportions and subtleties of preparation of 6 proven compositions

For several thousand years, plastering has confidently held the palm among others, including modern types of wall decoration. Now there are high-quality ready-made mixtures, but the price for them is high, so developers prefer to use home-made compositions for large volumes. Let's take a detailed look at 6 time-tested recipes for the preparation of plaster solutions and compare them with factory options.

Recipes 6 types of plaster

Any plaster or masonry mortar consists of 3 main components - a filler, a binder and a solvent. With a solvent, everything is simple, in all types of plaster water is used as a solvent, river sand acts as a filler, but the main secret of quality lies in the choice of a binder.

In the construction industry, 2 types of sand are used - river and quarry. They differ in that there is a significant percentage of clay in quarry sand, so this sand is not suitable for every solution.

Recipe #1: Clay Mix

Clay sandy plaster mortar has been known since time immemorial. Now the clay composition in its pure form is rarely used, since its performance is low. The only tangible plus is the affordable price, because clay can be dug up with your own hands, and sand is inexpensive.

If the facade is plastered with clay mortar, then it will have to be repaired every year. Clay is more suitable for interior walls in dry rooms, but here you should not expect special strength, once every 3 to 4 years such a finish requires cosmetic repairs.

One of the few areas where clay mortar is actively used to this day is plastering and laying furnaces.

The ratio of components in the clay-sand solution ranges from 1:3 to 1:5 (clay:sand). Here everything depends on the fat content of the clay, less sand goes into the "skinny" clay, more is added to the oily one. Instructions for determining fat content are below in the video in this article, and we will talk about the rules for preparing clay plaster.

Illustrations	Recommendations
	Step #1. Clay can be dug up with your own hands, while taking it from a depth of 1 m, since there are fewer impurities. If there is no desire to wave a shovel, then they buy a ready-made clay-sand mixture. There are many manufacturers, from personal experience I can advise the Makarov Furnace House brand.
	Step #2. The second step is soaking dry clay. It is poured into a container and filled with water. Clay gets wet from 3 to 20 days, while every day it is stirred.
	Step #3. When the clay is completely soaked, it is rubbed through a metal sieve in order to remove debris. As a result, you will get a composition similar to sour cream.
	Step #4. Add 3 parts of sand to the solution. Stir. Apply to a small section of the wall and leave for a day. If cracks appear after a day, then add more sand and try the composition on the wall again. So empirically find the right proportion for this particular type of clay.

Often cement, gypsum or slaked lime is added to the clay mortar. The choice of one or another binder component depends on the purpose of the room.

• Cement enhances the strength of the coating and increases the resistance of the wall to moisture.
• Lime improves elasticity.
• Gypsum promotes rapid setting, but this plaster does not tolerate a humid environment.

Recipe number 2: lime-gypsum mortar

Lime mortar with gypsum is interesting in that it is prepared both in its pure form (lime-gypsum) and with the addition of sand. The presence of gypsum causes a number of rules that must be observed during preparation.

• To prepare the starting plaster, 1 part of slaked lime and from 0.3 to 1 part of gypsum is taken. Sand goes from 3 to 5 parts.
• The finishing composition is prepared either without sand at all, or no more than 2 parts of sand are added. If sand is not added, then the lime-gypsum mixture is prepared in a 1: 1 ratio. When sand is added, the proportions change and are already 1: 1.5: 2 (lime-gypsum-sand).
• When working with gypsum mortars, you need to be especially careful about the cleanliness of containers and tools. If particles of the old get into the new batch, then it will harden one and a half times faster.
• During the preparation of the solution, water is first poured, then gypsum is added to it, then lime comes and sand closes the list. In this case, the solution is constantly mixed.

Recipe number 3: lime-sand mortar

Lime mortar is good if a large amount of work is planned in a dry room; when soaked, it is stored for up to 3 days. Best of all, it is taken on brickwork or starting cement plaster. You can also throw on wooden surfaces, but it is advisable to fill shingles (reinforcing mesh) there.

• For starting plaster, from 2.5 to 4 parts of sand are added to 1 part of lime dough.
• The final composition is prepared either 1:1 or 1:2.
• During cooking, sifted sand is poured in portions into a container with mixed lime and mixed.
• When the solution reaches the desired viscosity, it is desirable to rub it through a metal sieve, after which it is desirable to mix it again with a mixer and can be applied. If the solution is thick, it is diluted with water.
• When wet, the composition has a grayish tint, but after drying, the surface will become snow-white.

Recipe number 4: cement-lime plaster

A mixture of lime and cement gives a composition that is universal in its characteristics. It can be used in both dry and wet areas. Moreover, this mortar has a high elasticity and is well suited for facade work. The setting time is up to 2 hours, respectively, it can be prepared in large portions in a concrete mixer.

This composition is prepared in two ways:

1. Sand and cement are mixed dry, after which liquid lime milk is added to the container and everything is thoroughly mixed in a concrete mixer or a construction mixer.

1. If there was no concrete mixer at hand, then the following option is more suitable for a construction mixer: according to the recipe No. 3 described above, a lime-sand mortar is prepared, and cement is added at the end and everything is kneaded with a mixer.

Recipe number 5: cement-sand mortar

Cement mortar is considered a classic, but its elasticity is lower than that of its lime counterpart. However, this composition is excellent for finishing wet rooms, the basement of buildings and facades. Survivability time up to one and a half hours, the proportions are given below.

The scheme for preparing cement mortar is as follows:

• First, cement and sand are mixed dry, in this case quarry sand can be used.
• Further, it is desirable to sift the dry mass through a metal building sieve.
• Now, with constant kneading, the required amount of water is added.

To increase plasticity, some craftsmen add soapy water or liquid dish detergent to the water. It should be based on the calculation of 30 - 50 gr. for 5 liters of water.

Recipe number 6: terrazite mortar

Behind the tricky name hides one of the types of decorative plaster. On closer examination, the main load-bearing composition here is the above-described cement-lime plaster. The decorative effect is achieved by adding marble, granite or other mineral chips and mica.

Chromaticity gives a coloring pigment, so iron minium is used to achieve red color, chromium oxide will give green color, and burnt umber will give brown. Such compositions are fine-grained "M" (mineral filler up to 2 mm), medium-grained "C" (filler up to 4 mm) and coarse-grained "K" (up to 6 mm).

At the amateur level, such decorative compositions on the facade are easier to throw a "fur coat". In the most affordable version, a broom, a stick and a container with a solution are needed to put on a fur coat. With a broom you “scoop up” the solution and beat it against a stick towards the wall. Splashes of plaster fly onto the wall, so you gradually splash the entire facade.

What is added to the plaster

In addition to river sand, several types of fillers can be added to the cement-sand and cement-lime plaster mixture. They are used both to improve decorative qualities and to increase performance.

Illustrations	Recommendations
	Quartz sand. The range of sand is not limited to river and quarry types. Of great importance is the fraction of grains of sand, it ranges from tenths of a millimeter to 2.5 mm. For textured surfaces, a large fraction is taken, for smooth, fine.
	Special protection. In large cities and near industrial enterprises, serpentinite or barite sand can be added to the plaster. These fillers partially block X-ray, electromagnetic and other types of radiation.
	Marble chips. A crumb with a diameter of 1 - 4 mm is added to the plaster. Now such an additive is actively used for arranging the bark beetle cladding. To obtain a smooth marble-like surface, marble dust is added to the plaster composition. But this technology requires long-term grinding, so it is used only by professionals.
	Mica. There is an opinion that adding mica to the composition blocks the harmful effects of ultraviolet radiation on walls, but this is nothing more than an advertising ploy. In fact, mica gives a bright decorative effect; on a sunny day, such a facade will shine with all the colors of the rainbow.
	Styrofoam crumb. When crumbly foam balls are added to the composition, the thermal insulation characteristics of the coating increase significantly. But the thickness of such plaster should be from 1.5 cm, plus it must be covered with some kind of finishing layer, since the decorative qualities of the foam in cement are not high.

The subtleties of preparing solutions

In order for the plaster to lay well, it must have an optimal consistency. Moreover, adding a lot of water is not an option; with this approach, the lining will begin to crack as it dries. A too thick composition will not stick to vertical surfaces.

There is a folk way to check the readiness of plaster (in the photo, the stages go from left to right):

1. Run a trowel over the finished composition and see if “torn” furrows remain on it, then water must be added to the solution.
2. If after the trowel the composition spreads and no traces remain, then it is too liquid, it is necessary to add a dry mixture.
3. The solution is considered ready if, after passing a trowel over it, there are no gaps on the surface and the furrow does not change shape.

Using liquid soap as a plasticizer is certainly a cheap way, but not the best quality. To obtain a good quality solution, a ready-made plasticizer is added to it, the proportions are indicated on the product packaging. Fortunately, it needs very little and the price of such additives is relatively low.

Also, before plastering, the surface must be treated with soil a couple of times. In the case of home-made compositions, the treatment of walls with soil is mandatory, since, unlike factory mixtures, such plaster does not have adhesion enhancing additives.

Conclusion

Accurate adherence to the above described recipe and competent selection of components of plaster solutions will give a good result. If you have any questions, write in the comments, I will try to help.

May 22, 2018

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