Preparation of mortar for plaster: binder, filler, solvent, additives in the correct proportions. How to make a mortar for plastering walls correctly How to make a plaster mortar with your own hands

Plaster is an integral part finishing walls and ceilings. How long we won’t need it depends on its quality. redecorating. The quality itself plaster mixture, and then the plaster coating, depends on the composition.

Cement plaster mixtures

Cement plaster mixtures can be divided into two types:

• Cement-sand, used for leveling and finishing any surfaces except concrete. Cement plaster has poor adhesion to such a base.
• Cement-lime, used in finishing brick, concrete and ceramic surfaces

Both plaster compositions necessarily include special polymer additives and mineral fillers, which make the finished mixture more plastic, heat- and frost-resistant, and enhance its astringent and adhesive properties.

Preparing the plaster

Do plaster mortar You can use a ready-made mixture, or you can do it yourself. We add medium-fraction sand and a little liquid soap to the cement mortar, which extends the time of working with the mortar.

Below are the proportions of cement mortar for plaster. Composition of the cement-sand mixture:

• 1 part cement;
• 3 parts sand;
• water to the consistency of thick sour cream;
• liquid soap

Composition of the cement-lime mixture:

• 1 part cement;
• 3 – 5 parts sand;
• 1 part lime paste (one part quicklime + three parts water. Pour in the lime warm water, wait for the reaction to start, add more water and mix. Close and let it ripen for one day. Then we dilute it with water to a liquid state, pour it into the prepared hole, after a day we pour sifted sand on top, and earth on top. The maximum layer of sand and earth is half a meter. The lime is kept in the pit for 15 to 20 days; at the end of this period, lime paste is obtained, which is used in the preparation of plaster cement-lime mortar.);
• liquid soap or soap solution.

Preparation of cement mortar for plaster involves mixing sand and cement in the required proportions. Gradually pour the resulting dry mixture into either water or lime milk, add liquid soap. According to the intended purpose, we adjust the amount of liquid - for spraying the walls, a weaker solution is required, for rough plastering of the walls after spraying, a thicker one is required.

To prepare a cement mortar for plastering walls, it is enough to know the exact proportions of cement, filler and liquid, as well as follow simple rules.

1. Take a clean box with a flat, smooth bottom.
2. Pour clean sifted sand onto the bottom.
3. Pour cement on top.
4. Mix the dry mixture thoroughly, then level it with a rake.
5. Repeat point 4 several times.
6. We look carefully at the finished mixture, it should be a uniform color.

Advice. Prepare the working mixture in small quantities. After forty to fifty minutes it will set and begin to lose its properties, and the coating will turn out to be of poor quality.

There are three types of ready-made mixtures for plaster, prepared from factory dry ones. We determine their quality by using a trowel lowered into a container with the finished mixture.

1. Fatty. Excessively sticky, sticks strongly to the trowel. As it dries, it will crack and shrink. We adjust the ratio of the finished mixture to the filler by adding it and stirring thoroughly until we get the desired consistency.
2. Normal. A thin layer of cement mortar remains on the trowel.
3. Skinny. The presence of the mixture is barely noticeable on the trowel. In this case, the ratio of the dry mixture to the liquid must be adjusted towards cement, adding it and stirring thoroughly.

In the photo in this article you can see how to properly mix the solution.

Advice. When preparing this type of plaster mixture, use only slaked lime. When water is added, quicklime will enter into an uncontrolled reaction with it and it is not a fact that it will be completely extinguished. In the future, the remaining pieces of unslaked lime will come into contact with moisture, which will lead to tears in the plaster coating.

Plaster mixtures with little cement and too much sand have little plasticity and are very inconvenient to work with, so the optimal ratio of cement to sand is 1:3. We use cement grade M400, it gives the best results.

Application of cement plasters

Cement-based plaster mixtures are considered universal, as they can be used for both interior and exterior work; they are resistant to moisture and have good vapor permeability. You need to know that this mixture takes about 4 weeks to dry. But you don’t need to process it later than an hour after application.

Advice. The layer of plaster on the external walls of the building should be twice as thin as on the internal ones. In this way, normal vapor permeability of the walls is maintained, fungus does not form on them and condensation does not collect.

Except correct composition and mixing the plaster mixture, it is necessary to properly prepare the base, otherwise all the work will go down the drain and everything will have to start again.

Here are some tips for preparing the base (using a brick wall as an example).

1. It is necessary to level the surface and remove dried cement (if any).
2. Then carefully unstitch the seams brickwork(if there are any voids or recesses, leave them as they are).
3. We remove dust; if there are greasy stains, wash them off, wipe the surface with a damp sponge and let dry.
4. Cover the base with primer and let dry.
5. Prepare the mixture for plaster and begin application. We work from bottom to top and from right to left.
6. After about 40 minutes we begin the final leveling.

Advice. It is not recommended to work at temperatures above + 25 and below +5 degrees, as well as in rainy weather. If you still had to plaster in hot weather, it is recommended to regularly moisten the finished surface to avoid premature drying and cracking.

When starting a renovation, you need to decide for yourself how much effort you are willing to spend on it. Perhaps for you the best solution There will be a purchase of ready-mixed cement from well-known manufacturers.

No construction or renovation project is complete without quality building mixtures. For laying the foundation, as well as plastering walls, cement mortars based on sand, cement, water and additional components such as gravel or crushed stone are used. Moreover, only with the correct ratio of sand and cement can the required strength or elasticity of the mortar be obtained.

Ratio of sand and cement for mortar

Depending on the desired result, as well as the purpose of using the cement mortar, you can calculate the proportions or ratios of all the necessary components. The most famous and most commonly used cement mixture is made with proportions of 1:3, where 1 is cement, and 3 is sand. If you add more sand to the solution, it will become stronger, but not elastic. Thus, it will be difficult to apply to the surface and at the slightest mechanical impact it will disappear. In addition to the proportions of the composition, the quality of the solution can also be affected by the brand of cement used.

For individual construction work masters use cement mixtures with different brands. If M 400 cement is used for the M-100 composition, the ratio of the components will be 1:4. That is, the brand of cement obtained directly depends on the correct ratio of building components.

In addition to solutions, Construction Materials They are also marked. For example, M-100 can be used to build walls from M-100 brick, and M-115 mortar is used for facing M-350 brick. Additionally, for greater viscosity, builders use plasticizers.

Ratio of crushed stone sand and cement for concrete

The ratio of cement M-400 (C), sand (P) and crushed stone (SC) for concrete:

The ratio of cement M-500 (C), sand (P) and crushed stone (SC) for concrete:

In order to obtain an ideal concrete solution, you should know all the nuances of its production. The most important point is the calculation of the ratio of all components (water, sand, cement and crushed stone). Sand, gravel or other solids are considered concrete fillers.

Before kneading concrete composition you should decide on the brand of cement, as well as the desired result. There is a special table that determines the ratio of mortar grades and cement grades.

Considering the type of work the concrete will be used for, you can calculate the proportions for mixing it. Today, each master makes a solution using his own technology, since the addition of different components significantly changes its composition. But according to standards, the proportions of concrete are 1: 2: 4: 1/2, where 1 part is cement, 2 parts are sand, 4 are crushed stone and 1.2 parts are water.

If special additives are used for the solution to increase strength, drying speed, frost resistance or plasticity, then the proportions may completely change. In such cases, it is necessary to read the instructions for use of these substances.

The ratio of cement and sand for the foundation

Plaster based on cement binder is one of the most durable and durable. However, dry ready-mixes are quite expensive.

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

Varieties and recipe

On this moment The most widely used are two types of cement-based plasters. Their technical and operational characteristics are somewhat different from each other, which determines the optimal area of ​​their application and application methods.

Cement-sand mixtures

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

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

Cement mortar for plastering walls, proportions depending on brand

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

• Quartz sand and diabase flour – acid resistance;

Quartz sand

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

Colored coarse sand for decorating facades

Various types of sand-cement plaster

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

Instructions for preparing sand-cement mixture

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

The solution has the correct density if a hole of 2-3 cm remains after the mixer is pulled out.

Cement-lime mixtures composition and features

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

Advantages and disadvantages

The main advantages include:

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

The disadvantages include:

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

Table of proportions of cement-lime plaster ingredients

Application technologies

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

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

Plastering walls cement mortar with your own hands, video of ceiling leveling:

Plastering on beacons

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

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

Base primer

1. The outermost (corner) screws are screwed in on both sides and aligned strictly vertically along the heads. Twine is stretched between them over the surface of the caps.
2. By cutting the beacon, its placement under the twine is checked; it should fit end to end. The twine is removed.
3. The mixture for attaching the beacons is placed along the marking line. The beacon is pressed into it so that the surface is flush with the cap.
4. Vertical placement is checked using a rule.
5. The walls are plastered with cement mortar using beacons, using a covering method with a spatula or grouting using a trowel.
6. After filling the space between the two beacons with a layer slightly higher than the top level, 2 m usually leaning on the beacons, we remove the layer from the bottom up.
7. After the plaster has dried, the beacons can be removed from the wall and the grooves can be sealed. Embedded plastic models can be left.
8. Grouting is done until the plaster is completely dry. A solution of a thinner consistency than the main one is prepared.
9. The cement surface is pre-moistened, and then the grout mixture is applied under pressure by grouting at an angle of 45°.

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

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

Slopes

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

1. Slopes are checked for verticality;
2. If the difference is large and it is necessary to impose a large number of mixtures To strengthen the finishing layer, a mesh is attached to the slopes;
3. The surface is cleaned and treated with a primer;
4. A limiting strip is installed on the wall bordering the slope; the thickness of the facing layer will be oriented along it;
5. The solution is applied with a spatula to the mortar and carried along the slope from bottom to top;
6. After the solution has dried a little, the restrictive strips are removed and the corners are corrected.
7. The plastered surface is rubbed clean with a float soaked in water.

Plastering door slopes video:

Finishing slopes after window installation, video:

Cement-sand VS gypsum

In order to find out which plaster is better, gypsum or cement, let’s make a comparison based on the main operational and technical characteristics:

Vapor permeability

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

Consumption and cost

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

Viability of the finished solution

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

Moisture resistance

Possibility of use in rooms with high humidity and in facade works has only a cement mixture.

Thermal conductivity and heat resistance

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

Plastering walls is rightfully one of the most popular ways to decorate surfaces in the house. From appearance These surfaces largely determine the overall attractiveness of the interior and facade. To avoid having to redo unsuccessfully completed repairs in the future, purchase only high-quality raw materials to prepare the solution and carefully select the most suitable recipe, based on the characteristics of the surface to be decorated and a set of other criteria.

The entire structure of the plaster mixture for walls consists of three main groups of components:

1. Binding element. Most often, the following materials with this property are used for mortar for plastering walls:

• clay;
• gypsum;
• lime
• cement.

2. Filler. The main function of this material is to increase the strength characteristics of the solution and increase the volume of the mixture. For this purpose the following materials are used:

• slag;
• sand;
• shavings;
• sawdust.

2. Water. The liquid allows you to give the mixture the desired consistency for the most convenient application to the surface.

To prepare a solution for plastering façade and internal surfaces buildings also use decorative mixtures, the component composition of which includes:

• lime or alabaster for colored walls;
• Portland cement for finishing walls inside buildings and facades;
• marble, tuff, granite, dolomite, mica, glass to increase the durability of the coating and give a special shine.

Important! The following types of artificial or natural components are added as dyes:

• ocher;
• ultramarine;
• chromium oxide;
• iron lead.

Types of plaster solutions

There are many types of mortar compositions for plastering walls, the distribution of which into separate groups occurs according to the principle of the binding element taken as a basis.

The list below shows the most common combinations:

• clay;
• clay-cement;
• clay-gypsum;
• clay-lime;
• lime;
• lime-gypsum;
• lime-cement;
• cement-sand;
• cement-lime.

The types of mixtures are also classified according to their purpose, the distinguishing features of which are the proportions of the solution for plastering walls and a suitable complex of materials of all groups. In this direction, the following options are distinguished:

• decorative;
• for interior decoration;
• for rough finishing;
• façade

Technical characteristics of plaster

The strength of the future coating is determined by the brand of mortar for plastering walls. This indicator means temporary compressive strength, measured in kg/cm2. Based on the composition of the mixture, the following strength grades are established:

Depending on the thermal conductivity characteristics, mixtures of the following types are determined:

• heavy, otherwise called cold, whose volumetric weight is over 1500 kg/m3. They contain heavy fillers, which contributes to high thermal conductivity;
• light or warm, the volumetric weight of which is less than 1500 kg/m3. They contain materials with low thermal conductivity.

Important! It is mixtures of the second type that are often used for plastering all kinds of ceilings and walls. Experts note that the most popular solution is clay for plastering walls.

In addition to the above criteria-characteristics, when choosing the appropriate type, the following indicators are taken into account:

• adhesion;
• plastic;
• consistency of volume or shrinkage of the mixture after application;
• frost resistance;
• setting time.

Features of choosing plaster for a certain type of base

For each surface to be treated, the type of plaster mixture should be individually selected, since one material is not always combined with another.

Check out the following selection features:

1. To process wood and plaster, choose the gypsum-lime or clay-lime option.
2. For facades made of concrete or other stone of artificial and natural origin, which are constantly exposed to weather conditions, purchase mixtures based on slag cement or Portland cement.
3. For stone facades of artificial and natural rocks that are not exposed to weather influences, plaster material based on cement or lime is used.

Important! In rooms such as a bathroom, sauna, bathhouse, laundry room, where the humidity level constantly fluctuates, be sure to use cement or lime-based plaster as a base layer.

The cooking process includes several sequential procedures:

Recipes for making plaster

To obtain a high-quality plaster solution of the correct consistency, adhere to the following proportions when preparing suitable type from those suggested below.

Recipe No. 1 - lime dough

• quicklime - 2 parts;
• water - 6 parts.

Recipe No. 2 - cement mortar

• sand - 3-2 parts;
• cement - 1 part;
• water.
  Important! This solution has ultra-high strength and is used for outdoor robots.

Recipe No. 3 - cement-clay mortar

• sand - 3-5 parts;
• clay dough - 1 part;
• cement - 0.2 parts.
  Important! Clay dough is a liquid mass of water and clay.

Recipe No. 4 - cement-lime mortar

• sand - 3-5 parts;
• cement - 1 part;
• lime dough - 1 part;
• water.
  Important! Lime dough is also a mass of medium liquid, for the preparation of which dry powder and water are used.

Recipe No. 5 - lime mortar

• lime - 1 part;
• cement - 3 parts.

Recipe No. 6 - lime-gypsum mortar

• alabaster or dry gypsum - 1 part;
• lime dough - 3 parts.

Recipe No. 7 - lime-clay solution

• lime dough - 2 parts;
• sand - 15-18 parts;
• clay dough - 6 parts.
  Important! How most sand you add, the stronger the strength of the solution.

Recipe No. 8 - clay-gypsum solution

• sand - 3-5 parts;
• clay dough - 1 part;
• gypsum - 1/4 part.

Video

Watch a video on how to quickly prepare a plaster solution from a suitable ready-made dry mixture from the manufacturer. The principle of preparation from individual components is similar, only you need to mix the dry substances in the required proportion yourself.

Conclusion

The procedure for preparing the plaster mixture itself is not complicated. The main condition for obtaining a high-quality result is to take into account all the features of the structure and conditions of subsequent operation when choosing a specific recipe. It is equally important to adhere to the specified rules regarding the proportions and technology of applying the composition when forming the coating. In this case, you will be able to achieve the most durable coating with a long period of maintaining integrity.

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

Solutions options

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

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

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

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

Quality of wall solutions

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

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

Plastering process

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

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

Characteristics and composition

Now we choose which composition is suitable for specific purposes.

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

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

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

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

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

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

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

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

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

Modern materials

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

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

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

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