Preparation and use of lime-cement mortar

Specifications

The composition of such a solution must include cement, sand, slaked lime and water.
It is worth paying attention to the fact that it is slaked lime that needs to be added. Otherwise, the quenching reaction will begin in the solution itself when water is added, and bubbles, forming inside the solution, will lead to cracking of the plastered surface

This process of bubble formation will lead to deterioration in the quality of the solution and to brittleness after it dries.

Construction mixtures, their composition and properties are regulated by various GOSTs. This is necessary for standardization and regulation of norms in construction. GOST 28013-98 is the main legal act regulating the technical requirements for building mortars and materials included in the composition.

This standard also includes characteristics of quality indicators, acceptance rules and conditions for transportation of finished solutions. It contains the qualitative and quantitative characteristics of masonry mortars, materials for plastering and for interior work, used in various operating conditions.

Advantages and disadvantages

Marble plaster has a number of advantages:

• versatility - it can be applied to any surface of materials used in construction - concrete, plasterboard, brick, starting plaster;
• environmental friendliness - the components included do not pose a health hazard;
• practicality - due to the peculiarities of the texture, such plaster can be applied directly to the surface without filling small potholes, cracks, etc.;
• fire safety;
• possibility of repair - if any area is damaged, there is no need to remove the entire coating from the wall; the same composition can be applied to the damaged area to hide the problem area;
• variety of assortment in texture and color;
• long service life, since this coating is resistant to temperature changes, moisture and does not fade under the influence of direct rays of the sun.

The main disadvantage is the fairly high cost.

The industry produces a large number of mixtures for preparing marble plaster. It is usually sold in packages of ten or twenty-five kilograms; there are also ready-made water-based mixtures.

To save money, you can prepare a solution of marble plaster yourself.

To do this you will need the following components:

• Cement-sand mixture or slaked lime - 1.89 liters;
• Flaxseed oil - 360 milliliters;
• Water – 180 milliliters;
• Soap base or liquid soap - 30 milliliters;
• Marble flour or marble chips of the required fraction – 1.89 l.;
• Coloring pigment, you can use synthetic or mineral.

Liquid soap can be replaced with a soap solution prepared in this way - 10 grams of laundry soap are rubbed with shavings and melted in 30 milliliters of water in a water bath.

• first the dry ingredients are mixed;
• pour the mixture with water;
• add linseed oil, liquid soap;
• mix thoroughly until a homogeneous mass is formed.

To save money, some of the marble chips can be replaced with crushed granite of the same fraction as the chips.

Marble plaster takes quite a long time to set. In this case, it is not allowed to cover the walls in separate areas. If such plaster is applied to the next area after some time, then when it dries, the parts to which the finishing was applied at different times will be visible. Therefore, such plaster is prepared immediately before use in the required quantity and immediately applied to the surface.

Plastering with marble plaster is a fairly simple job that does not require high professional skills. Due to its unusual structure, such plaster does not require perfect leveling of surfaces and hides small cracks.

To improve the quality of adhesion of the plaster to the surface of the walls, it is recommended to treat the surfaces with a primer before applying it.

Cement mortars

Cement is prepared from a mixture of ordinary cement and medium sand. The proportions can be different, they depend on the brand of cement used and can be: for one part of cement, take from three to six - sand.

Mix the dry mixture with the addition of water until a homogeneous mass is formed.

First, the dry mixture is mixed, then water is gradually added, then everything is mixed until a homogeneous, thick mass is obtained. But this option is not the best, since ordinary cement is inactive, even when using any brand it turns out to be too hard and too strong.

The cement-lime composition for bricklaying consists of lime and cement. The cooking process is as follows:

1. Slaked lime, that is, lime dough, is diluted to the state of thick milk, and then filtered through a sieve.
2. A dry mixture is prepared based on sand and cement, which is dissolved with lime milk, after which it is thoroughly mixed. Adding lime can increase the plasticity of the resulting mixture; this mixture is recommended for use for laying any type of brick.

Simple masonry mortar

The simplest solution is prepared from a binder (it can be ordinary cement or lime) and sand. In some cases, clay can also act as a binder, but this is very highly specialized work that is not performed very often.

The most common cement-sand mortar has the following proportions: one part of cement to three of medium-fraction sand. The resulting mixture is thoroughly mixed first in dry form, after which plain water is gradually added to it. Stirring is carried out until the resulting composition acquires the proper density and mobility.

Checking such characteristics is not so difficult: the container in which the solution is mixed must be tilted at an angle of forty degrees; if the mixture does not pour out, then you can begin the masonry process.

Complex installation solution

The solution should not spread or slide well off the surface.

A complex brick mix is ​​a mixture of several components and a binder material that affects the physical characteristics. Among such complex mortars for brickwork, cement-lime-clay, cement-lime and others are used, thanks to which the masonry is simpler, but also reliable.

Clay, for example, is added to make the composition more plastic. It does not fall apart during operation and is installed very neatly and easily. The use of plasticizers makes the brick mixture indispensable when laying facade walls. This mixture is very economical, it provides uniform compaction, and when spread, it is conveniently leveled over the surface of the previous row. Therefore, many experts recommend spending a little more time preparing the solution, but then this will only help in the work.

Clay plaster mortar

We can rightfully say that this is the most ancient finishing material. This solution is used for leveling and plastering wooden, adobe, brick, and stone surfaces in rooms with low humidity.

Making such a solution will take quite a long time, since the clay will need to be pre-soaked. Preparation work is carried out in the following sequence.

To make the clay mortar for plastering internal surfaces more plastic, add a little lime to it, add a little cement to increase strength, and add a little gypsum to speed up coagulation.

• The dried clay is cleaned, then filled with water and mixed. The prepared mixture is left for one day (if the clay is very oily, it may take up to three days).
• The wet clay is kneaded and ground, gradually adding water, until a mass with the consistency of sour cream is formed.
• The resulting mass is rubbed through a sieve.
• Add 1/5 sand and mix well.

The clay mortar for plastering is ready.

The resulting solution can be stored for a very long time. If it dries out, just add water to return it to a working consistency.

Mixture proportions

There is a classic version of the mixture, which is determined by the ratio 1:3 - 1 part cement and 3 parts sand. Both components are first mixed dry with each other, and then water is added to this mixture in portions. All this is thoroughly mixed until a solution is formed, the consistency of which is similar to thick sour cream. Be sure to give the finished mixture 15 minutes to thicken, after which it is mixed again.

By the way, the cement-sand mortar “lives” for no more than 1.5 hours. After which it begins to lose moisture and dries out. So a small batch is a justified decision.

To mix the components, it is recommended to use a construction mixer or a drill with a special attachment. If you need a large volume of material, for example, to pour a foundation, then we recommend carrying out the preparation process in a concrete mixer

Please note that the end result is a lump-free composition in the form of a homogeneous mass

Sand for masonry mortar

Main ingredients of the solution:

Cement is a binding component. It must be in paper bags. It is recommended to buy it before starting construction processes. That is, it must be “fresh”. After all, during long-term storage this material cakes, which means it loses its qualities. Sand is a filler. There is one point regarding quality here. There should be no foreign materials in the sand. This is especially true for clay. Therefore, it is recommended to purchase river sand

Pay attention to the fraction of the material. For example, fine material promotes the spreading of the mortar, so it is not used for masonry mixtures. But in screed mortars, such sand is an ideal choice

The coarse fraction is not used for preparing plaster, although it works great in foundation mortars. Water is the basis, so it must be clean. The main requirement for it is the absence of acid and oil impurities.

Features of choosing a brand of solution

Now you can move on to the proportions and understand such an indicator as the brand of solution:

• The masonry composition is grade M100. It is used in the construction of walls and barrier structures made of bricks or blocks based on different materials. To do this, you will need M400 cement and sand, which are mixed in a ratio of 1:4.
• To increase the strength of the masonry, you can use M200 grade mortar. To do this, you will have to reduce the amount of sand by 2 times.
• To level the floor bases, the M300 grade of mortar is used. To do this, you can use cement M400 or M500 with the addition of water and sand in a ratio of 1:3:0.5.
• To plaster the walls, use exactly the same solution as above, only with a slight increase in the amount of cement. For example, it could be 1.2-1.5. Plaster mortars are often made with the addition of lime milk. This reduces the strength of the material, but increases its ductility. In this case, the cement-sand-milk ratio will be 1:5:2.

Standard proportions

Making the solution in the correct ratio

There are certain technological standards that regulate the ratio of building mixture components. Here are three examples:

1. To prepare the screed solution, use proportions of 1:2-1:6. In this case, the amount of water is not indicated, but only the cement-sand ratio is indicated.
2. In low-rise construction, 1:3 or 1:4 solutions are most often used.
3. For erected structures - from 1:3 to 1:6.

Why don't the standards specify water? The fact is that it is easy to make a mistake with the volume of water. After all, the sand may be wet, and it is impossible to determine the degree of humidity at home. At the factory, this indicator is strictly controlled. What can you offer to those who use handmade solutions? To do this, it is better to double the batch if the first one turns out to be liquid. Just add cement and sand to it according to the standard, but reduce the amount of water.

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Today, facing tiles and stone are placed on ready-made adhesive mixtures, which greatly simplifies the process of preparing the composition. But since we are considering all cement-sand mortars, we should not ignore this masonry material. Let's just designate the proportions - 1:2.4:0.4. This is such a non-standard ratio.

Many people ask a question regarding determining the volume of one serving. What means and instruments can be used to measure the required amount of material? Construction stores sell special measuring buckets, with the help of which the building mixture is measured or weighed.

Cement plaster

This is the most economical type of plaster. It includes:

• cement - one part;
• sand - three parts;
• liquid soap;
• water in the volume necessary to bring the mixture to a consistency like thick sour cream.

When preparing cement plaster, you need to follow the sequence of actions - at the first stage, two-thirds of the required amount of water is poured into the container, then the required amount of cement and lime is poured in, mixed thoroughly until completely mixed with water, then sand is poured in and mixed for three to five minutes with special equipment (you can use a drill with a mixer attachment). The resulting mixture should have a uniform gray color and be free of lumps.

Requirements for masonry mixture

The requirements for masonry mortars are described in detail in GOST 28013-98. According to this document, the following requirements apply to mortar mixtures:

• the composition must have a high degree of adhesion to brick and other substrates;
• withstand large amounts of freezing and defrosting;
• to ensure that the masonry does not collapse under the influence of atmospheric influences and temperature changes, the masonry mixtures must have high water resistance;
• due to the plasticity of the mortar, during the laying process, it becomes possible to timely adjust the position of the masonry material, which significantly increases the quality and productivity of the work;
• water-retaining properties prevent decomposition of the mixture and precipitation of heavy fractions;
• the strength characteristics of the composition are decisive in the calculation of building structures. This parameter shows what maximum loads the material can withstand. The brand of the solution reflects its strength in kgf/cm2.

Failure to comply with these requirements leads to the formation of cracks in the brickwork, increased consumption of the mortar mixture, increased thickness of the joints and reduces work productivity.

Lime plaster - what is it good for?

Plaster with lime as a base is used both in the interior decoration of residential premises and in the decoration of house facades. Lime owes its popularity largely to its low cost, good adhesion to various surfaces and sufficient reliability. The properties of plaster based on slaked lime have been known for a long time - these are very good fireproof properties, thermal insulation properties, high vapor exchange rates, ease of use and elasticity, environmental friendliness, absence of cracks when driving nails, high antifungal properties.

Wooden beams or partitions coated with lime mortar will not be worn down by rodents and beetles. Perhaps the only disadvantage of lime is the fear of moisture, which is why plastering the walls in the bathroom with lime is a rather risky undertaking. However, it is enough to add another component to the lime mortar, which will make it impervious to moisture.

Making sawdust concrete with your own hands

Independent production of lightweight concrete composite is carried out according to the following algorithm:

1. The necessary materials are being prepared. There is no need to purchase components in advance. All components can be prepared immediately before production by visiting stores or building materials warehouses, as well as using waste from woodworking enterprises.
2. The ingredients are mixed according to the proportions. Mixing of components can be carried out mechanically using a concrete mixer or manually using shovels. Automation of the technological process through the use of a concrete mixer increases productivity, improves mixing intensity, and has a positive effect on product quality.
3. Molding is in progress. The group molding process is predominantly used, when the pre-mixed composition is poured into several dozen molds. Single and group forms of collapsible design are used, made of wood 2 cm thick and upholstered in metal or plastic. The use of polyethylene film makes it easier to remove finished products.
4. The finished product is dried naturally. The molds are removed 4–5 days after pouring by loosening the wing nuts, removing the threaded rods and disassembling the molding box. The natural drying process lasts, depending on the type of wood, up to three months, during which the moisture concentration is significantly reduced and the product acquires operational strength.

Standard composition of concrete with sawdust: cement-sand mixture, wood shavings, lime (if necessary)

Terrasite plaster mortar

This type of mortar is used in cases where it is necessary to obtain plaster with increased decorative qualities, for example, to obtain the effect of chipped stone. You can get different colors and shades.

Terrasite mixtures are divided into three types depending on the size of the filler:

• M – fractions up to two millimeters;
• C – fractions from two to four millimeters;
• K – fractions from four to six millimeters.

Depending on the fraction, when obtaining flowers, one or another amount of ingredients is added.

For example, for compositions of three primary colors:

• Cement grade 200, terrazite grade M, S, K, - one part;
• Fluff lime, terrazite grade M, S, K – one part;
• Quartz sand - for terrazite grade M - nine parts, for terrazite C and K - five parts;
• Marble chips - for grade M it is not added, for grade C and K there are three parts;
• Mica - for all three types of terrazite 0.5 parts;
• Iron minium in relation to the weight of the finished mixture in% for all types of terrazite - 2.5 parts.

To obtain green compositions, use the following proportions:

• Cement grade 300 for all types of terrazite – 0.75;
• Fluff lime – for all types of terrazite 2 parts;
• Quartz sand - for grade M terrazite - 7 parts, for grades C and K - five parts;
• Marble chips - not used for grade terrazite M, for grades C and K three parts;
• White marble flour – for all types of terrazite, two parts;
• Chromium oxide in relation to the weight of the finished mixture in% for all types of terrazite 0.5.

Why are plasticizers needed?

Plasticizer is a special compound added to the solution to increase its plasticity and elasticity.

Beneficial effect of using a plasticizer:

• Reducing the amount of water that impairs the hardening of the solution.
• Increasing the moisture resistance of the seam.
• Increased frost resistance.

Plasticizers have different purposes:

• Catalysts. Serve to speed up and increase the strength of the hardening of the solution.
• Modifiers. Allows you to obtain additional capabilities of seams - greater resistance to mechanical stress, moisture resistance, etc.

In addition, plasticizers make it possible to obtain a more elastic seam that compensates for thermal expansion of the cladding. This ability helps maintain the strength of connections with the load-bearing wall and prevents the appearance of cracks in the seams that can accumulate moisture.

Peculiarities

Plaster mortar is a wide range of mixtures. The spectrum includes various compositions, this is explained by the purpose of each material. The basis of any raw material is a binder. In addition to it, manufacturers include various additives in the composition. This is a pasty mass. It is spread on the walls or ceiling, stretching until a uniform layer is formed.

The composition of each mixture directly affects its purpose. For this reason, mixtures can be intended for interior or exterior use. Some compositions are relatively universal and are designed to work indoors as well as outdoors. A distinctive feature of these mixtures is their resistance to adverse environmental factors. One of the features of plaster compositions is granularity.

It is the size of the faction that indicates whether the composition is finishing or starting. Often it is the rough texture that is used to prepare the base for finishing. Depending on this, one or two plasters are used on one surface. In this case, one of them is preparing the base for applying the other. Due to the particle size and additional effect, the cost of the finishing coating is always higher than the starting counterpart.

Sometimes the plaster mixture is confused with the term “dry plaster,” which is usually understood as plasterboard sheets.

In fact, plaster is a composition based on a powder mixture or a ready-to-use solution.

In the first case, it is a binder and fillers in a balanced formula. They must be mixed before applying the plaster material to the prepared base. The second variety is notable for the fact that it does not require adjustment before use on the surface.

This material can have different shades. It depends on the components of the mixture.

• In one case it is a gray concrete color, in others it is dirty beige, sometimes milky.
• White is considered to be the basic color.
• The finished material on a creamy base can be colored. However, the range of shades of such mixtures is scarce. This forces you to paint the plaster mixtures yourself.

All solutions are divided into fatty, lean and normal. Mixtures of two or more components are called complex. In fatty varieties, the astringent component predominates. Therefore, they shrink and crack and require re-processing.

If the filler dominates, the solution does not shrink, but does not adhere well to the base. The normal composition is moderately plastic, easy to work, and durable.

It is impossible to prepare a plaster composition without having an idea of ​​the types of such mixtures. In the modern construction market, the buyer is offered a wide range of similar products in different forms of release. It varies in volume and composition.

There are several popular mixtures:

• cement-sand;
• cement-lime;
• gypsum;
• clay;
• adhesive;
• polymer;
• specialized.

Each type of plaster has its own advantages, durability, and disadvantages. For example, specialized compounds are nothing more than insulating and waterproofing mixtures. These are intermediate masses-alternatives to mineral wool and other cladding. With their help, you can get rid of annoying noise from outside and prevent moisture from entering.

Cement-sand options are ordinary cement mortars and masonry mixtures with high resistance to mechanical loads. They shrink during the drying process and are suitable for use in heated and unheated rooms. Cement-lime mixtures are distinguished by the presence of fine sand in their composition. Suitable for indoor use and have antibacterial properties.

Clay varieties are environmentally friendly. They contain asbestos, lime and cement. Less durable compared to cement compositions. Gypsum plaster mixtures are often used as levelers. These compositions are hygroscopic and are not suitable for finishing rooms with a high degree of humidity. With frequent contact with water, they wear out and deteriorate.

Adhesive plaster mixtures are needed to fix insulation or waterproofing. Most often, such products are used when leveling surfaces when working with mesh. Polymer plasters do not have sufficient ventilation, however, they have high fire resistance and sound insulation. They are made on the basis of acrylic and silicone. There are silicate varieties.

Making your own solution

First you need to slak the lime for the plaster so that it is suitable for work. This requires a metal container, since the reaction is accompanied by a large release of heat and an increase in volume by 3 times. The lime packaging indicates the slaking speed: slow (25 minutes or less), fast (8 to 10 minutes), medium, 15 to 20 minutes. It is better to mix the mixture with a shovel or oar. Slaking is carried out for at least a day, however, ideally use lime that has been standing for a month.

The note! The sand also needs to be prepared before preparing the plaster: remove impurities, clean it by passing it through a sieve.

Instructions for creating a limestone-sand mortar:

1. Sand is mixed with lime paste in the selected proportion. This is done dry and mixed thoroughly.
2. After which water is gradually added to the container. There is no need to pour in the entire volume at once; it is poured in in a thin stream, and the solution is constantly stirred.

Now that the preparation is complete, you can begin plastering the surface.

Instructions for mixing lime compounds

This material was previously used everywhere. Its main advantage is its relatively low cost and high mechanical strength. The preparation of this type of plaster solution is as follows.

If quicklime is used, you will have to spend considerable time slaking it. To do this, dry lime is poured into a container, after which cold water is poured into it. As a result, a violent reaction will occur, which will be accompanied by heating and splashing, so the mixture in the container should occupy no more than 40% of the volume. When pouring liquid, you must wear protective clothing and goggles. After the reaction is complete, the mixture is closed and left to infuse for 2 weeks.

After this, you need to grind the slaked lime so that there are no lumps left in it. To do this, use a sieve through which the material is ground. Before diluting the material with water, add a small amount of sand to the container with lime and then mix. Add sifted sand to the homogeneous mixture in the amount of 3 parts per 1 part of lime paste. You need to pour the material in small portions, constantly stirring and adding a little water. The result should be a solution with the density of thick sour cream.

Important! Such mixtures dry within 12-14 hours, so you need to make plaster in the amount that is used at a time. You also need to constantly clean the mixer attachment after each mixing of the plaster.

What is lime plaster

Adding lime to solutions can significantly increase the ductility and crack resistance of plaster. It becomes much easier to work with, it does not dry out as quickly, it even sticks easily to wood, and the surface is smoother and free of defects. It also provides excellent protection against mold and mildew. Another indisputable advantage is its environmental friendliness - unlike synthetic additives, lime is absolutely harmless.

Lime is widely used in construction as a plasticizer. However, when plastering facades, it should be taken into account that it can only be used in areas with a dry climate. Such solutions are not recommended for use in rooms with high (over 60%) humidity.

Lime plaster is considered warmer and more vapor-permeable, that is, “breathable,” and it is much easier to remove it from the walls in case of repairs than, for example, ordinary cement plaster. But excess lime can weaken the strength of the surface. That is why it should be added in moderation, strictly adhering to the proportions.

As you can see, lime plaster has many advantages. The disadvantages include not such high strength as that of cement compositions. It is also not recommended to use it in damp areas and

But such a solution does not require special strength. After all, the purpose of plastering is to level the surface and cover up small cracks. A more durable solution is required when laying. However, even in this case, according to SNiP, it is allowed to add a small amount of lime paste or clay to it to increase plasticity.

When slaking lime, you should be extremely careful - splashes of the hot mixture can cause burns. The smallest lime dust that can settle on the mucous membrane also has a harmful effect. Therefore, when working, you should use protective clothing, gloves and a respirator.

Plaster with lime mortar

Preparing the walls

If you are not renovating a new building with bare walls, then you need to remove all the previous finishing.
Old wallpaper is moistened with water and removed with a scraper or wire brush. If it is necessary to completely remove the old layer of whitewash, the surface can be moistened with liquid paste. After it has dried, the whitewash along with the glue can be easily cleaned off with a spatula. Large cracks are widened with a grinder or a knife, dusted off, primed, and then covered with durable cement mortar. Their locations are taped with sickle tape.

To securely fix the plaster on concrete or brick walls, notches approximately 10 cm wide are made with an ax or hammer drill. Wooden walls are covered with shingles - strips of wood. It is secured with nails, and there is no need to drive them deep - part of the nail must be bent. You can replace shingles using a metal mesh stuffed onto the surface.

The walls must be primed before applying the first layer. The primer will glue the remaining dust and increase the adhesion of the plaster.

When perfect evenness is required, guide beacons are used. They are attached to the wall with a small amount of putty, then leveled. The distance between the beacon profiles should be 20 cm less than the length of the rule that will be used to level the mixture during plastering.

Applying plaster

Let's consider the technology of plastering walls with your own hands, without using machine application. To obtain a high-quality surface using lime plaster, you will need three layers:

1. The spray is used for better adhesion of the subsequent layer to the surface. In this case, the solution is prepared with a more liquid, creamy consistency. It is simply thrown onto the walls in a small layer and not leveled.
2. Main primer layer. Its thickness is 1-3 cm. It is a thicker solution. Apply with a trowel or trowel between the beacon profiles. The rule is to level the plaster and remove excess.
3. Finishing layer (covering). Used to smooth the surface and remove minor defects. The consistency of the solution is similar to a spray. The layer thickness is several millimeters. After application it is rubbed with a grater.

Advice! Since lime mortar sets more slowly, it is not recommended to apply a primer layer that is too thick, as it may “float.” If necessary, it is applied again with a second or third layer, drying each for about a day. Such a surface should be rubbed only after the plaster has completely dried.

If after some time the plaster needs to be repaired, it can be done in the same sequence as the initial application: clean out chips and cracks in the finish; prime the wall; apply the mixture in several layers; rub it in after drying.

Preparation of masonry mortars

Since various types of mixtures can be used for masonry mortar, let us consider in more detail how to prepare mortar for bricklaying.

Cement mortar proportions

Sand-cement compositions are widely used in capital construction and other areas where increased demands are placed on the strength characteristics of brickwork.

When starting to prepare masonry mortar, you should remember that excess cement in the working mixture does not increase its strength, and in some cases, even worsens its characteristics. Only strict adherence to dosage will ensure optimal performance properties of the masonry mixture. The proportions of the most common cement-based compositions are given in SP 82-101-98, which clearly regulates the percentage of ingredients in various types of cement masonry mixtures.

The table shows the percentage of ingredients in cement masonry mortar, depending on the brand of cement used.

Scope of application of cement mortar depending on strength characteristics

Below is the scope of application of different brands of masonry mortars.

• M25.
  Used for plastering and floor screeding. The composition does not contain any additional ingredients.
• M 50.
  Used for brick and stone masonry in the construction of low-rise buildings and structures. May contain plasticizers, dyes and other additives.
• M 75.
  Used for laying concrete slabs, installing reinforced concrete structures, erecting internal partitions and installing concrete floor screeds.
• M 100.
  Widely used in monolithic construction, masonry work and pouring light-loaded strip foundations.
• M 150.
  Used primarily for foundation work on loose soils.

Proportions of cement-lime mortar

The percentage ratio of cement, lime and sand in cement-lime mortar is given in the table.

The solution is prepared in the following sequence:

1. Fluffed lime is diluted to the consistency of kefir, and then filtered.
2. Separately prepare a dry sand-cement mixture.
3. Strained lime is added to the cement-sand mixture and mixed thoroughly until a homogeneous mass is obtained.

Proportions of cement-clay mortar

The ratio of cement, clay and sand in a cement-clay masonry mixture is given in the table.

The addition of clay increases the ability of masonry mixtures to retain moisture.

The low strength of lime mortar prevents its widespread use in masonry work. Most often, lime mixtures are used for plastering work. The proportions of the working solution depend primarily on the fat content of the lime and can range from 1/2 to 1/5.

Lime-gypsum mortar

It is used for plastering wooden, stone, fiberboard surfaces in rooms with normal humidity. It is a lime mortar with the addition of gypsum to speed up the setting and drying processes.

The amount of ingredients added depends on the required thickness of the future plaster:

• with a thickness of one and a half centimeters, 12 liters of lime mortar, 6.4 kilograms of gypsum and 7 liters of water will be required;
• with a thickness of 2 centimeters - 16 liters of lime mortar, 8 and a half kilograms of gypsum, nine liters of water;
• with a thickness of two and a half centimeters, you need to take sixteen liters of lime mortar, 10.6 kilograms of gypsum, eleven liters of water;
• with a thickness of three centimeters, twenty-four liters of lime mortar, 12.1 kilograms of gypsum, and thirteen liters of water will be required;
• thickness three and a half centimeters, you need twenty-eight liters of lime mortar, thirteen kilograms of gypsum, thirteen liters of water;
• a thickness of four centimeters will require thirty-two liters of lime mortar, 13.4 kilograms of gypsum, fourteen liters of water;
• thickness five centimeters - forty liters of lime mortar, fifteen kilograms of gypsum, fifteen liters of water;
• six centimeters thick - forty-eight liters of lime mortar, seventeen kilograms of gypsum, seventeen liters of water.

This type of plaster solution must be prepared very quickly and immediately applied to the surface - it sets in two minutes and hardens in half an hour.

Concrete mortar and its composition.

Cement should only be stored in a closed, dry place! Per 1 bag of cement, the dosage of concrete mortar is as follows:

This solution is used for various construction works (screed, foundation, floors, beams). Steel reinforcement is placed into concrete to increase strength, resulting in reinforced concrete. Bonding the reinforcement to the mortar makes it easier for the metal surface to oxidize.

Calculation of the required volume of concrete is calculated using the formula:

Volume of concrete = Length x Width x Height, for example: 10 x 5 x 0.1 m = 5 m3

When adding water to a solution or building mixture, the following proportions must be observed:

Volume of water = Weight of cement / 2, for example: 25 liters of water per bag of cement weighing 50 kg.

Marble plaster

Modern technologies have made it possible to eliminate such a disadvantage of this type of finishing as color heterogeneity. Since during the preparation of mixtures, as a rule, marble was used, obtained from different layers, the surface was heterogeneous. The use of modern coloring pigments has not only significantly expanded the color range of marble plasters, but also made it possible to eliminate this defect and obtain stable shades. Modern tunics are also resistant to ultraviolet radiation from sunlight. Today, marble plasters in rooms stably retain their color for more than twenty-five years. Marble plasters are divided into the following types based on binders:

• acrylic;
• cement-sand;
• limestone;
• based on gypsum.

If you need to get a very smooth plastered surface, use very fine sand with a grain size of Ǿ 0.25-0.5 millimeters. If you want to get a rough surface, add coarse sand or fine gravel.

Based on the size of marble granules, they are divided into:

• coarse-grained with a particle size of 0.2-1 millimeter;
• medium-grained with a particle size of 1-3 millimeters;
• fine-grained with a particle size of 3-5 millimeters.

The larger the size of the granules, the more prominent the texture.

The composition consists of the following components:

• Marble chips. To reduce cost and also improve performance, you can add granite chips of fine fractions;
• Binders. Usually acrylic resins and various mineral additives are used;
• To improve performance and protect the coating from the development of mold, fungi, and various bacteria, biologically active substances are added that prevent their development.

To enhance the decorative qualities, mother-of-pearl is added to the composition.

Preparation of simple plaster compositions

Cement mortar is the simplest and most common.
Simple plasters include those mortars based on a single binder. These include the following plaster solutions:

1. Cement.
2. Lime.
3. Clay.
4. Plaster.

Cement

This composition is the most common type of finishing: its consistency is very similar to brick laying mortar. However, the density in this case is different, and the use of various additives and plasticizers is widely practiced.

Although this may sound unexpected, what most closely requires personal control is the quality of the sand used. That is why, before use, it is carefully sifted through a special sieve to remove all impurities and debris.

After cleaning the sand, the mixing procedure begins: the main components must first be mixed dry. The proportions of cement mortar for plastering walls outside the room are taken in a ratio of 1:5 sand to M500 cement. As for the interior finishing, in this case cement is mixed with sand 1:4, where M400 cement is used for preparation. After the dry ingredients have acquired the required homogeneity, water is added to the composition and stirred until it becomes mushy. To carry out such a procedure, both a trough and a construction mixer can be used.

Lime

In lime mortar, lime acts as a binder.

This composition differs from the previous one in the absence of cement: in this case, lime is used as a binder: it must only be slaked and have excellent qualities. The first step is to thoroughly grind it so that the particles are as small as possible. Then water and sand are added to the vessel with lime powder, constantly mixing the entire material

It is very important that the resulting lime mortar for plaster does not contain lumps, with the density of the mixture resembling dough. Then another portion of purified sand is added to the resulting mass in a ratio of 3:1

After this, the final stirring of the plaster is carried out by adding water: the finished consistency of the solution should resemble thick sour cream.

Clay

This easy-to-prepare plaster mortar is the oldest known. With the development of construction technologies, its composition has undergone some changes, because clay in its pure form is quickly washed off by rain. To strengthen the finish, it is practiced to add cement, lime and gypsum, which helps to increase its durability and reliability: while maintaining the availability of preparation. In the process of preparing clay plaster, the main component must be thoroughly cleaned of all kinds of debris and impurities. Then clean and dry clay is soaked in water for 3-5 hours until it is completely soaked: the preparation of the solution is completed by adding sand to its composition, at the rate of 2-4 parts of sand to one part of the clay mixture. Typically, clay plaster is used to decorate interior spaces.

Gypsum plaster

Most often, final operations on leveling walls are carried out using gypsum plasters, with the possibility of application not only on concrete and brick, but also on wooden bases. The first recipe for preparing such a solution involves using 3 kg of chalk and 1 kg of gypsum, while the chalk is crushed to dust, and then mixed with gypsum. In this case, water is not used, since 5% wood glue is used as a solvent. The proportions of glue in this case vary, depending on the required thickness of the final solution. This type of solvent not only makes the mass of plaster homogeneous, but also allows you to somewhat slow down the hardening process. However, the drying speed of gypsum plaster is still quite high.

Working with gypsum plaster requires skill, as the mixture dries quickly

The second method of preparing a finishing mortar from gypsum is especially suitable in cases where it is necessary to plaster painted bases or chipboard partitions. In this case, you will need to take 2 kg of gypsum, 1 kg of drying oil and 100 g of drier: after thorough mixing, the composition must be immediately prepared. The reason for this is the lightning-fast drying of the drier: when working in this case, you will need appropriate construction skills.

Do-it-yourself mortar for plastering walls - how to prepare different types + tips from experts

In construction, plaster plays a very important role. The use of the simplest and improved options allows you to level the surfaces of walls and ceilings for further finishing with tiles, wallpaper, and so on. High-quality plaster options themselves can serve as decoration for indoor surfaces. Also, a properly selected plaster solution creates a surface that keeps the room cool in the hot summer and warm in the winter.

Unlike plasters that are used to finish external walls, plasters that are applied to indoor surfaces are not exposed to weather or ultraviolet radiation during operation. At the same time, the applied and hardened plaster turns out to be an element of the environment in which a person is located and can affect his health. Therefore, when creating plaster mixtures, one of the first places is to ensure environmental safety. In this regard, plain water is usually used as the basis for solutions. It is allowed to include in some plastering mixtures only those polymeric materials that are not only safe for health, but also their decomposition products are environmentally friendly.

An important factor when choosing plaster is its decorative effect. At the same time, some types of plasters can be used both for finishing interior spaces and for finishing the surfaces of facades and plinths of buildings.

Proportions of cement mortar for brickwork

For brickwork, as for plaster, cement-lime or cement mortars are created. However, it must be taken into account that in this case the grade of mortar should not be higher than the strength class of the bricks used for masonry. It is most convenient to work with plastic mortar: it is easy to apply, but does not drain from the masonry elements. In order to prepare a mixture with optimal consistency, you need to know the most successful ratio of all components of the solution.

Preparation of branded cement mortars

The brand of mortar depends on the ratio of cement and sand in the mortar. The more sand and less cement, the less durable the solution is and, accordingly, the lower its grade.

• 1 part cement: 5 parts sand - the proportion of preparation of the MZ grade solution;
• 1 part cement: 4 parts sand - the proportion of preparation of the M5 grade solution;
• 1 part cement: 3 parts sand - the proportion for preparing the M8 grade solution.

Recipe for plastic cement mortar M3 for brickwork

To create 1000 liters of M3 grade solution you need:

• water – 340 l.;
• sand – 2064 kg;
• cement – ​​268 kg.

To create 200 liters of M3 grade solution you need:

• water – 54 l.;
• sand – 206 l. (330 kg.);
• cement – ​​33 l. (43 kg.).

To create an M3 mortar from a 25-kilogram bag of cement, you need:

• water – 32 l.;
• sand – 120 l. (192 kg);
• cement – ​​25 kg.

Recipe for plastic cement mortar M5 for brickwork

To create 1000 liters of M5 grade solution you need:

• water – 350 l.;
• sand – 2000 kg;
• cement - 327 kg.

To create 200 liters of M5 grade solution you need:

• water – 56 l.;
• sand – 320 kg;
• cement - 52 kg.

To create an M5 mortar from a 25-kilogram bag of cement, you need:

• water – 27 l.;
• sand – 177 kg;
• cement - 25 kg.

Recipe for plastic cement mortar M8 for brickwork

To create 1000 liters of M8 grade solution you need:

• water – 360 l.;
• sand – 1904 kg;
• cement – ​​412 kg.

To create 200 liters of M8 grade solution you need:

• water – 58 l.;
• sand – 305 kg;
• cement – ​​66 kg.

To create an M8 mortar from a 25-kilogram bag of cement, you need:

• water – 22 l.;
• sand – 115 kg;
• cement – ​​25 kg.

Recipe for plastic cement-lime mortar M3 for brickwork

To create 1000 liters of M3 cement-lime mortar you need:

• water – 470 l.;
• sand – 1760 kg;
• cement – ​​191 kg;
• hydrated lime – 106 kg.

To create 200 liters of M3 cement-lime mortar you need:

• water – 75 l.;
• sand – 282 kg;
• cement – ​​30.5 kg;
• hydrated lime – 17 kg.

To create a plastic cement-lime mortar of grade M3 from a 25-kilogram bag of cement, you need:

• water – 61 l.;
• sand – 230 kg;
• cement – ​​25 kg;
• hydrated lime – 14 kg..

Cement-lime mortar for masonry. What mortar is needed for laying bricks

Properly formulated masonry mortars must comply with the following standards:

1. Competent choice of masonry mortar recipe, proportions of sand and cement and volumes of raw materials.
2. Use of quality components.
3. Careful preparation of materials.
4. Compliance with production technology.

By adhering to such requirements, it is possible to create high-quality cement for brickwork, which will have the following advantages:

1. Optimal plasticity of the mixture. This parameter contributes to the effective sealing of recesses in masonry layers.
2. Hardening time. Large volumes of solution, which hardens quickly, are unsuitable for use. To eliminate this phenomenon, you need to add lime to the composition.
3. Increased strength. When the mixture hardens, the strength characteristics of the cement layers will be increased, and the brick wall will become resistant to deformation and other negative factors.

To ensure effective formation of solid CPS, it is necessary to correctly select the proportions of the solution. During the reaction of the components with water, the strength indicators increase, and the connecting component combines the building materials into a solid structure.

Regardless of the recipe used, the masonry mortar and proportions of sand and cement must include the following ingredients:

1. Knitting part. In most cases, masonry cement is used, which begins to harden when interacting with liquid, connecting with the rest of the mortar.
2. Filler substance. Designed to improve performance properties and increase the volume of the mixture.
3. Liquid. Water is used to react with the binder part of the additive and promote normal hydration.

The role of a substance with astringent properties can be performed by the following types of raw materials:

1. Portland cement.
2. Lime.
3. Lime-cement mixture.

When figuring out which cement is best for bricklaying, you need to take into account the type of tasks for which it will be used and the characteristics of the brand.

The masonry composition is mixed using pure sand from a river or quarry, which does not contain various inclusions such as clay, grass or roots. To increase strength, you can add fiber to the base.

Cement mortar for bricklaying must contain additional components, including:

1. Additives to increase frost resistance. Their task is to prevent crystallization of liquid under the influence of frost and normalize hydration.
2. Plasticizing additives. Promote the workability of the working composition and facilitate its operation.
3. Hardeners. They improve the polymerization process of binder additives and reduce the period of strength development.
4. Dyes. Using colored pigments, you can change the range of materials and improve the aesthetic properties of the wall.

The final grade of the composition is determined by the proportions of sand and cement for bricklaying. As the sand content increases, the grade decreases, and as the proportion of cement increases, the grade increases. To mix mortars, different brands of cement-sand mixture for bricklaying are used, but M75 is the most common. In this case, the proportions of cement and sand for bricklaying are selected in the ratio 1:5:0.8.

Materials marked M75 contribute to the reliable bonding of different types of brick and stone, ensuring high resistance of buildings to negative influences.

Application and self-production of the solution

This mixture is prepared on site before work, or ready-made dry lime plaster is used, diluted with water in the required ratio. “How to prepare lime material for plastering?” This question, related to the economic aspect, often arises among craftsmen and customers.

It is obtained in several stages by extinguishing the boiling water. To do this, dry lime is poured into a suitable container (but not plastic), then completely covered with slightly heated water. Then you need to cover everything with a heavy lid to avoid splashes around the perimeter of the room. Some time after the reaction, the white liquid is filtered through cheesecloth, the thick mass is left for one day for subsequent thickening.

Sand should be sifted through a sieve with holes of 3 to 5 mm. You need to add a small amount of water and sand into the dishes, avoiding the appearance of lumps. When finished, the resulting mixture has normal fat content and consistency. It will set slowly, and therefore its shelf life will be about 2 days after production.

The use of lime plaster for interior work can improve the heat and sound insulation characteristics of structures, and is also a kind of protection against fires. It can serve as a basis for finishing similar materials.

How will tiles laid on limestone behave? Lime absorbs water well, as a result of which the plastered surface will be subject to deformation. Therefore, in this case, the tiles may crumble.

Do-it-yourself lime-based plaster is easy to make. First you need to get the so-called milk of lime. The lump lime should be covered with warm water in a suitable container. Wait until the end of the chemical reaction and strain using cotton or gauze. The resulting mixture can be added after 24 hours during the preparation of the working solution.

Then you should mix the sand, cement or building plaster, pour the milk of lime into the dry mixture and mix all the components until a homogeneous mass is obtained. Adding PVA glue will help speed up its setting. The reverse process will ensure that liquid soap, laundry detergent and other detergent components are introduced into the mixture.

Application Features

The work cannot be called easy. The whole process is divided into successive stages. Ideally, before trying and applying the mortar yourself, it is recommended to watch a video on how to plaster walls with cement-sand mortar. Then, based on what you saw and securing everything with the instructions below, you can do the job correctly.

Required Tools

Plastering with cement is carried out with a standard set of tools. Scroll:

1. Trowel or plastering ladle.
2. A metal brush to clean the surface.
3. Spatulas of different sizes.
4. Plumb and level.
5. A rule that can be used to control unevenness on walls.
6. Grater and polisher to make the surface smooth and remove grooves.
7. Container for preparing plaster.
8. Bucket for water.
9. Roller and brush.

As for materials, a primer for cement plaster will be required to increase adhesion and reduce the ability of walls to absorb moisture.

Preparing the base before plastering

The quality and durability of the created layer will depend on this stage. Sequence of work:

• Remove everything unnecessary from the room.
• Clean the walls down to the base if the old layer falls off.
• If the wall is made of brick, then to improve adhesion they need to be deepened by 1.5 cm.
• When working with a concrete surface, you need to remove its smoothness. To do this, notches or grooves are made on the wall, depth 3 mm, length 15 mm. For 1 m2 you need 250 such notches. The furrows are made with bush hammer or teeth. All that remains is to clean the wall with a brush and wet it with water.
• If the wall is made of wood, then shingles or metal mesh are used to improve adhesion and reinforcement. The shingles are made from 15x4 mm planks, fixed so that diamond-shaped cells are formed. A metal mesh is placed on a clean wall.

After this, you can prepare the material and start working.

Mixture proportions per 1 m2

If you buy finished products, then you do not need to know the cement consumption per 1 m2 of plaster. It is enough to follow all the instructions from the manufacturer indicated on the container. However, when cooking with your own hands, such information is required. This way you can save money on your purchase.

The rate of cement consumption per 1 m2 of plaster can be indicated on the packaging from the cement manufacturer, taking into account a layer thickness of 10 mm. It is different for each brand. To find out the proportions, you need to decide on the layer thickness and increase the indicators on the packaging. Let's take the average consumption for plaster at 8.5 kg/m2. The table below shows what cement consumption is required for plastering at different layer thicknesses:

Cement mortar for plastering walls, the proportions of which have already been discussed above, is created immediately before the start of work, since its lifetime is from 30 minutes to 360 minutes.

Drying time

This determines when you can begin subsequent work, for example, puttying, wallpaper, painting. Complete hardening occurs within 30 days. Then the cement finally gains its strength. But how long it takes for cement plaster to dry on walls is another question. As practice shows, it will take a day for a 1 mm layer to dry. If the layer is 2 mm, then two days, etc.

Plastering

The easiest way is to use the machine method. But it is not suitable for beginners. The work is carried out in 3 layers: spray, primer, covering. The walls can be covered with primer and wait until dry. The best way to make the walls even is to install beacons.

The lighthouse is a smooth guide that defines the plane. It is installed on the wall using putty. Several beacons are fixed at a distance slightly less than the length of the leveling tool - rules (from 60 to 100 cm). Cement plaster for interior work should be applied to the space between the created beacons. First, the spray is applied with a trowel or ladle. The second layer (soil) is applied after the spray has dried. Moving from bottom to top, the mixture is thrown onto the wall. As a rule, moving from bottom to top along the beacons, the surface is leveled, becoming perfectly flat. The excess is removed with a trowel.

At the end, a covering is made to give the surface a smooth finish. When the layer has set, but has not yet dried, it is rubbed with a grater. The room is cleared so that the finish can dry. Now everything is ready to apply the finishing coat.

Lime mortar: characteristics and difficulties in manufacturing

When addressing this issue, it is necessary first of all to focus on the types of lime itself.
It can be slaked and quicklime (main types). For lime mortar, only slaked lime can be used. But the process of extinguishing it can take several weeks, which significantly slows down the finishing work. Therefore, many people prefer to buy lime mortar and protect themselves from additional hassle. Moreover, even after the required period, the lime may not meet the required quality. There may be some unextinguished lumps left in it. After applying the resulting solution to the surface of the wall, cracks and small bumps appear, spoiling the appearance and complicating further work.

An alternative is quick-slaking lime. When calculated, the final price for lime mortar will be higher, but you won’t have to wait weeks without any guarantee that the mortar will ultimately be as needed.

Types of cement-sand plaster

Despite the abundance of modern offers of dry mixes, cement-based compositions remain the most popular to this day. A layer of cement plaster performs aesthetic and sanitary functions, it is used to level surfaces, it protects walls from various types of damage, it is an excellent thermal insulator and absorbs noise well.

Based on their composition, solutions are divided into:

Watch how slopes are plastered with cement mortar; video tips will help you do the work yourself.

Cement-sand mortars

Cement-sand compositions are used for external and internal work, they are very durable, not afraid of moisture, temperature changes, durable, the only drawback is that the solution takes a long time to set and dry. The main element of the composition is cement - this is a binder, the brand of which determines the area of ​​application of the plaster:

• M150-300 – interior decoration;
• M300 and more – facade work, open balconies, rooms with a difficult microclimate, for example, bathrooms.

Sand is the second important ingredient of the cement mixture, the quality of which determines the reliability and strength of the solution. It is recommended to use sand of medium fraction; small sand grains in the composition can lead to cracking of the plaster layer after drying; they are added to apply the last thin layer to obtain a smooth surface. Coarse sand is used only in facade finishing.

Cooking features

Premature addition of water can reduce the quality of the solution, which also depends on the fat content of the lime itself. It can be determined during the kneading process. Lime dough sticks to the shovel - lime is greasy and you need to add a little sand.

If the solution falls off the shovel without stopping, there is too much sand and you will have to increase the amount of lime. The quantity is determined experimentally. It is added little by little, taking into account that the solution should adhere well to the surface of the wall, giving up some of the moisture.

To prepare a cement-lime mortar, ready-made slaked lime (fluff) is mixed with dry cement in a 1:1 ratio, then 4 parts of clean dry sand are added and mixed thoroughly. Now you can gradually introduce water at the rate of 1 liter per 10 kg of mixture. If necessary, increase the amount of water without stopping mixing the composition.

The clay filled with water should stand for 3 days.

Making a lime-clay composition is perhaps the most difficult thing. First you need to prepare the clay itself. It is filled with water and left in a cool place for at least 3 days. Once saturated with water, the clay becomes soft and pliable. After the allotted time, excess water is drained and lime dough is added to the finished clay mixture. Only after obtaining a homogeneous composition can sand be introduced into it. As it thickens, add water.

It is possible to make any plaster lime composition with high quality only by observing all existing proportions:

• 3:1 – lime and gypsum;
• 1:4 – lime and sand;
• 1:1:4 – lime, cement and sand;
• 1:3 lime and clay.

The hardening time and development of the solution depends on the introduction of a fixative into the composition. An important condition is the use of ready-made slaked lime (fluff) and complete high-quality preliminary slaking of the alkaline powder. Otherwise, the remaining lumps will cause cracking and the appearance of a mesh on the surface of the plastered walls. For more information on preparing the solution, watch this video:

Before work, it is necessary to clean and level the surface, let the composition sit well (if gypsum is not included in it). It is necessary to prepare a sufficiently capacious container in advance, since the lime increases in volume during the slaking process.

In cases where it is planned to create a finishing coating on top of lime plaster, it is necessary to wait until the solution has completely dried, otherwise the surface will begin to crack and collapse.