Cement-lime mortar is used for masonry and plaster work. Its composition is the same as that of a mixture with cement, but with the addition of slaked lime. Depending on the proportions of the introduced components, its characteristics and purpose change, it is used for finishing work both outside and inside the premises. You can make it yourself or buy ready-made.

Lime mortar has an increased degree of adhesion. It adheres well to almost any surface, including wood and concrete. Due to the bactericidal properties of lime, the likelihood of mold or fungi is eliminated. Such a composition is able to pass moisture without disturbing the microclimate in the room. Withstands temperature fluctuations from -50°С to +65°С.

Unlike cement mixture, lime is more elastic. It perfectly fills all the cracks and cavities. The applied plaster can be corrected within 1-3 hours. Mortar with cement is only up to one hour. Due to this long drying, the likelihood of cracking is minimal.

To distinguish compositions with lime and cement, there is such a technical characteristic of the solution as fat content. It is on it that the scope of its application is determined.

There are the following degrees of fat content:

• normal;
• skinny;
• oily.

Most often, a solution with a normal level of fat content is used, since it has the most optimal plasticity, rarely shrinks and does not crack. Skinny ones are suitable for surface cladding and have minimal shrinkage. Fatty ones consist of a large amount of an astringent component, therefore they are highly elastic. They are used for laying bricks or other block material.

The characteristic of fat content depends on the ratio of the components of the solution. To get lean, add more sand, greasy - more lime. They also differ in density: low (up to 1500 kg / m3) and medium (from 1500). The ratio of components affects the scope of the solution. The most commonly used grades are M50 (for plastering) and M75 (for bricklaying).

Also, cement-lime plaster mortars are divided into the following types:

• basic;
• decorative;
• special purpose.

The first option is used to level any surfaces and is used as a rough layer. Decorative ones dry for a long time, making them easy to process and give the desired shape and patterns. Special-purpose mixtures have increased moisture-proof characteristics, absorb noise well and provide thermal insulation.

Do-it-yourself solution preparation

Compared to cement-sand mortar, lime mortar has a lower price. For 1 m2 with an application layer thickness of 1 mm, about one and a half kg will be required. For kneading, you will need to buy sand, lime and cement. The ratios of the components depend on the required grade of the mixture. To get a solution of M75, you need to mix everything in the following proportions - 1: 0.8: 7 (M500 cement, lime, sand) or 1: 0.5: 5.5 if M400 cement. To mix the M50 brand, Portland cement M400 is required. The proportions of the components are 1:0.9:8 (cement, lime, sand).

Also, the proportions of the solution depend on the thickness of the application layer. For rough work (spray), knead in the following ratios - 6.7: 1.5: 1: 2.2 (sand, lime, Portland cement, water). For a layer of medium thickness - 9:2.2:1:2.8, as a top coat - 13.5:3:1:4.

Mixing a lime mixture usually requires no more than 0.8 parts of water to one part of Portland cement. This ratio is also affected by the dryness of the components. The main thing is that the cement mortar should be similar in consistency to thick sour cream.

Before kneading, lime must be extinguished. If this is not done in advance, then swelling will appear in the solution due to a chemical reaction. A separate container is used for extinguishing. The slaking technology depends on the type of lime. It can be fast-extinguishing, medium and slow. The first type is quenched as follows: powder is poured into a container filled with water. As soon as the chemical reaction begins, water is added and everything is mixed. The extinguishing process will end in 8 minutes.

Lime of medium slaking speed is slaked in the same way, but it takes longer - about half an hour. Slow-extinguishing lime powder is not poured with water, but only sprinkled. Quenching lasts until the entire volume increases by 3 times. The reaction takes more than half an hour.

In order for the lime mortar to turn out to be of high quality, the main thing is to observe the proportions, since all its characteristics and the final result depend on the ratio of the components. Portland cement is recommended for mixing, rather than conventional cement, as it has better strength.

If the mixture is mixed for laying a large amount of bricks, it is recommended to use a concrete mixer. She will make it absolutely homogeneous. First, water is poured in, after which Portland cement, lime powder and sand are poured. Once everything is thoroughly mixed, water is added again and everything is brought to the desired consistency.

• Slaked lime is filtered through a sieve with a mesh diameter of up to 3 mm. Sand and Portland cement are poured into the resulting milk of lime. All components are thoroughly mixed, and the mixture is brought to the required degree of fat content.
• In dry form, sand is mixed with Portland cement until smooth. Strained slaked lime is slowly poured. Bring to the desired consistency with water.

To improve the technical characteristics, plasticizers are added, additives that make the solution frost-resistant, hardening time accelerators or retarders, and so on.

Overview of manufacturers and prices

The best known manufacturers of lime mortars are Besto, Osnovit, Knauf and Henkel.

Cement-plaster composition Besto brand M100 is available in paper bags weighing 25 and 50 kg. It includes Portland cement M500d0, slaked lime, water-retaining components, sand of different fractions - 1 and 0.6 mm and polypropylene fiber, which increases the strength properties of the solution, or rather, reinforces it. It is applied by Besto to internal and external works. It can be applied both manually and with the help of equipment. The finished powder must be diluted with the amount of water indicated in the instructions. With a layer thickness of 1 cm, 18 kg of the mixture per 1 m2 will be required.

Dry Osnovit PC21 Startwell is packed in 25 kg bags. Contains components that increase the frost resistance of lime mortar. It also has moisture-retaining additives, so it can be used for finishing rooms with high humidity or for facades. Strength grade - B10. Consumption is the same as that of Besto - 18 kg/m2 with a thickness of 10 mm. The diluted solution can be used for two hours at a temperature of +5 to +30°C.

Moment Henkel is intended for surface treatment indoors only. Henkel Powder can be used as an intermediate layer, which is subsequently topcoated. The closed mixture must be applied within an hour. The layer thickness for one application should not be more than 2 cm. Packed in packages weighing 25 kg.

Dry powder MP Leight Cement contains perlite and polymer additives. Used as a leveling layer. Can be used both outdoors and indoors. Packed in bags of 30 kg. For 1 m2 with a layer thickness of 1 cm, 13.4 kg will be required. Applied either by hand or by machine.

The cost of cement mortar with lime depends on the volume of the bag, the purpose and the manufacturer.

Table with prices at which you can buy ready-made dry lime mixtures:

Lime mortar is sold in paper bags with different weights. When purchasing it, you should check the integrity of the bag, it should not have holes or glued places. You also need to pay attention to storage conditions. It should not be stored in a damp room, as cement quickly loses its strength characteristics. In addition, the powder seizes and lumps form. If you use such material for masonry or plaster, then cracks will appear in it after drying. To increase the degree of adhesion of the finished surface, it is necessary to clean it from dirt, old finishes and greasy oil stains. It can also be treated with a primer or concrete contact.

For the construction of strong and durable masonry, it is necessary to follow certain rules for the preparation of masonry mortars.

In this article, you will learn how to choose the right ratio of masonry mortar components, what masonry mortars are, and how to properly prepare them for brickwork.

Basic requirements for the solution

The solution that you will prepare for the construction of a brick bath must meet several mandatory requirements.

Firstly, it must be flexible enough to fill well all the irregularities of the seams and voids in the bricks.

Secondly, it must have sufficient strength after solidification so as not to cause deformation of the brick walls.

Thirdly, the masonry mortar must have sufficient setting time to allow it to be used before it begins to set.

Depending on the composition, plasticity should be maintained for 1.5-5 hours.

Cement-sand masonry mortar

The easiest to prepare and most often used in private low-rise construction is a masonry mixture of cement, sand and water.

For preparation, you will need Portland cement grade 400 or 500, clean sand with a fraction size of up to 2 mm and water.

The more sand in the composition, the less strength it will have and vice versa.

Most often, the following ratios of sand and cement are used, depending on the brand:
M25 - 5: 1;
M50 - 4: 1;
M75 - 3: 1.

As you can see, the amount of sand in them differs significantly. For particularly critical masonry areas, it is advisable to use a solution of the M50 and M75 grades. Most often, this is the device of columnar brick foundations in wet soils, the device of the socle parts of the bath, and other critical parts of the building under construction.

In other cases, a solution of the M25 brand is quite suitable. For its preparation, 1 cubic meter takes approximately 2064 kg of sand, 268 kg of cement and 340-350 liters of water. The amount of cement and sand for different grades is shown in the table below:

You can also determine the amount of cement for the preparation of a cement-sand mortar from the following table:

The ratio of sand and cement for laying the basement of the walls below the waterproofing level is shown in the table below:

Mortars for laying foundations and plinths below the waterproofing layer

As you can see, for different types of soils, the ratio of components will be different.

Useful advice: To prepare the solution, it is best to take river sand, which, before mixing with cement, is recommended to be sieved through a construction sieve to separate pebbles, pieces of earth and various debris.

After preparation, the cement-sand mortar retains sufficient plasticity for 1.5-2 hours. Therefore, its amount, prepared at a time, must be calculated in such a way as to have time to use it up before it begins to harden.

It is best to prepare the mortar in a special electric mortar mixer, first adding a little water, then cement, sand and then the remaining water. Mix the components for at least two minutes, then pour the finished composition into a tub.

During the masonry, the composition in the tub should sometimes be stirred so that it does not delaminate.

Cement-lime mortar

In some cases, it is advisable to add lime to the composition of the masonry mortar. The addition of lime significantly increases the time of preservation of its plasticity (up to 5 hours), which allows you to cook more at a time.

In addition, the addition of lime makes it possible to improve the spreading and filling of irregularities in the joints, as well as to reduce the number of cracks in the already hardened masonry.

However, such a composition should not be used where exposure to moisture is possible (for example, in wet soils).

For the preparation of a cement-lime mortar, cement grade 400, hydrated lime and sand are used in the following proportions:
for grade M25 - 1:1:4 (cement:lime:sand);
for the M50 brand - 1: 0.5: 4.5.

Below is a table of the ratio of lime, cement and sand in different brands of mortar:

Here you can make the necessary calculations for the preparation of mortar for masonry with your own hands. Enter the required number in the "Volume of solution" column, select the brand and you will get the exact proportions of cement, sand and water. Mortars are prepared for different purposes, for example, for laying the walls of a house and laying the walls of a furnace, the preparation recipe is somewhat different. Be careful when calculating.

Mortar for laying bricks

For many years, bricks were used to build walls, but the development of building technologies has led to the fact that new materials have appeared on the market - blocks of aerated or foam concrete, ceramic blocks, as well as blocks of expanded polystyrene. In order for the walls of the building to be strong and resistant to various atmospheric influences, different solutions are prepared for laying various types of building material. For this, building mixtures with a cement, cement-lime or lime base are used.

Cement mortar is used for the construction of walls from concrete blocks, ordinary or clinker bricks. It should be noted that the brand of such a mortar for masonry should not be higher than the strength class of the material used for the construction of walls. The solution should be plastic, easy to apply and not drain from the wall. To ensure these qualities, plasticizers are added to the composition of the mixture, and in order for the solution to maintain the water resistance of the seams, sealing additives are added to it. It is especially good to use cement mortar for walls that are exposed to precipitation or are in a humid environment. It can be the walls of the foundation or the facade of the building, the basement, the walls of the chimneys.

How to prepare the solution yourself?

To obtain a solution, cement is mixed with sand having an average fraction. To prepare the simplest mixture, 3-4 parts of pure sifted river sand of the middle fraction are added to 1 part of cement. The dry composition is mixed well, and then water is gradually poured until the solution turns into a homogeneous mass with the required level of mobility. However, such a composition quickly hardens during masonry, therefore, to increase plasticity and astringent qualities, clay or plasticizers are added to it. Such a mortar is easier to level on the wall surface, it will provide a better seal, and the masonry will look neat. A small amount of soap, detergent or washing powder can be added to the mixture as astringents.

Masonry mortar grades

Solution M25. This is a cement mortar for laying bricks or laying other types of stones. The mortar brand M25, is its official and correct name, is used both in special literature and in the practice of construction work. Mortar M25 refers to mixed (complex) mortars for masonry. M25 cement mortar consists of mortar filler, binder and water. The role of the filler for the M25 solution is usually played by ordinary sand. Moreover, the cleaner the sand, the higher the strength of the solution.

Solution M50. It is one of the most popular. It is a mixed, complex mortar for laying bricks and other types of stone, mesh floor screed. M50 consists of a binder, water and filler. The filler is sand well cleared of clay, which improves the strength of the cement mortar. The binding element is cement, water is used, of course, also purified.

Solution M-75. The strength of the M75 cement mortar depends on the proportions in which sand is mixed with cement, as a binder, and water. M75 is a high-grade mortar, its proportions are 1 part cement to 3 parts sand and a little less than one part water. Therefore, it is plastic and durable, which makes it easy to use. Cement mortar M75 is indispensable for the installation of precast concrete structures, pouring leveling screeds, brickwork.

Solution M-100. M100 cement mortar is mainly used in masonry and plastering works, as well as in the manufacture of cement floor screeds. The main difference between the m 100 mortar and concrete of a similar brand is the absence of coarse aggregate (crushed stone) in the mixture. Naturally, the composition itself is also different. Significantly higher content of cement and sand than in concrete of the same grade. Mortar M-100 can also be referred to as: cement, building, masonry, plaster mortar.

What is needed to quickly solidify the solution?

To increase the hardening time of the composition during masonry, a cement-lime mortar is prepared. To do this, lime paste is added to the cement-sand mixture. First, 2/3 parts of water are poured into the cooking container, then 1 part of cement and lime are poured out, mixed well for at least 15 minutes, then the remaining water and 3-4 parts of sand are added. Such a solution is also used for the construction of walls made of foam and aerated concrete, having previously added special foam additives to it, which will increase the thermal insulation of the joints.

Lime mortar is used in the construction of internal walls or interior partitions. It is characterized by high plasticity, so the walls will look neat. To prepare the solution, mix 1 part of quicklime with 3 - 5 parts of pure sifted sand, mix until a homogeneous dry mass is obtained, and then add the required amount of water. The solution must be homogeneous and free of lumps.

In the case of preparing a mortar for masonry, its composition depends on the quality of the components used, weather conditions, temperature fluctuations and is determined empirically in each case.

Cement-lime mortar is a mixture with high adhesion, strength and elasticity. It has proven itself as a masonry mortar for building blocks and bricks, as well as for plastering various surfaces indoors and outdoors. The scope of application is not limited to finishing works, this also includes laying pipes, processing reinforcing mesh, pouring monolithic floors. One of the most important advantages of such a composition is reliability and moisture resistance.

In addition to the above properties, lime is also characterized by bactericidal properties that prevent the formation of fungi and molds. It is worth noting, unlike cement mortar, the ability of the material to pass moisture, which has a positive effect on the level of humidity inside the room. Hence resistance to temperature extremes up to 65 °C and frost resistance down to -50 °C.

Good adhesive properties make it possible to work with any materials, even with wood. The mixture is easy to lay, filling even the smallest cracks and bumps. The increased plasticity of the lime mortar makes it possible to extend the drying time to three hours, thereby avoiding cracking.

According to the characteristics of fat content, the following lime compositions are distinguished:

1. normal - with an optimal degree of plasticity, practically do not crack and shrink when dried;

2. skinny - used for any facing work, as they have minimal shrinkage;

3. greasy - a highly plastic material with a large amount of binders, therefore it is well used as a masonry mortar.

Fat content can be adjusted by adding various components. So, to lower the value, porous sand is added, and lime increases the fat content back.

According to the ratio of density, solutions are divided into:

• low density - up to 1500 kg/m3;
• medium density - from 1500 kg / m3.

The ratio of the components of the solution determines the scope of its application. The most popular brands are M75 and M50. For example, the M75 mixture proved to be the best as a reliable masonry mortar for bricks. Whereas for a wider area of ​​​​use, as well as for plastering work, we digest M50.

With regard to plaster mixtures, they are conditionally divided into:

1. basic - for rough leveling of the surfaces of walls and ceilings;

2. decorative - having decorative elements in the structure or due to prolonged drying, they are easily subjected to textured processing with subsequent painting;

3. special - are of a technical nature to improve the moisture-proof properties, sound insulation and insulation.

Manufacturers and prices

Another plus is the affordable cost of the material compared to the cement-sand mortar. Its low consumption (1 m2 layer in 1 mm - 1.5 kg of the mixture) determines the economic benefits. Lime mortar can be bought from manufacturers ready-made or in the form of a dry mix packaged in bags. Construction manipulations indoors are allowed to be carried out with powder compositions, while for outdoor work, especially under conditions of high humidity, it is recommended to entrust the preparation to professionals.

The cost depends on the quality of the raw materials used, the ratio of ingredients. An approximate price range is shown in the table below.

The line of manufacturers of ready-made dry mixes is quite extensive. All of them have their own characteristics, features in the composition and scope. Below are the most accessible and common.

Do-it-yourself solution preparation

In addition to ready-made production options, it is possible to make lime mortar yourself. Buy all the necessary high-quality elements and carefully observe the proportions to achieve a high-quality result while saving money. The main ingredients used are cement, sand, lime and water.

The ratio of ingredients determines the brand and specifications.

Water consumption during preparation is usually 0.8 parts per 1 hour of cement. In practice, the amount of liquid is determined visually by the consistency of the solution - normally, the mixture should look like thick sour cream.

Lime, as a building material, is used only in a quenched form, otherwise, as a result of a chemical reaction, the finished material may swell or burst completely. For preparation, you will need a separate container. The process differs depending on the rate of quenching.

1. Fast-extinguishing lime is poured into a barrel of water until completely immersed. After the appearance of soaring, more water is added and mixed. Extinguishing takes an average of 8 minutes.

2. Medium-extinguishing lime is poured into a container and filled with water in double volume. When steaming, water is also added and mixed. The process continues for approximately 25 minutes.

3. Slow-extinguishing lime is only moistened with water. The reaction is accompanied by a threefold increase in volume and an increase in temperature. Takes over 25 minutes.

The prepared material is diluted with water in a ratio of 1: 1 to the state of milk of lime. Often, for the final extinguishing, it is poured into a special pit, sprinkled with a layer of sand and earth and aged in this way for 15-20 days. The composition acquires a creamy consistency and is now called lime dough or paste.

For cement-lime plaster mortar, the most commonly used cement is:

• type I Portland cement with a minimum amount of additives and a high setting rate;
• Type II Portland cement grades M500-400 with additives up to 35%.

As practice shows, three-layer plastering is most often used at construction sites. The proportions of the solution (water-sand-lime-cement) in this case will depend on the layer of plaster.

• draft layer - spray - 2.2: 6.7: 1.5: 1;
• middle layer - soil - 2.8: 9: 2.2: 1;
• finishing layer - covering - 4:13.5:3:1.

For the preparation of masonry cement mortar, it is more expedient to use a concrete mixer, since in practice it is required more than plaster. The latter, in turn, is prepared in improvised containers using a construction mixer.

Part of the water is poured into the concrete mixer, then cement, lime and sand are alternately added in the required proportion. After thorough mixing, the mixture is closed with the remaining water.

In the case of manual preparation, there are two types of procedures:

1. The lime dough is passed through a sieve with a mesh diameter of not more than 3 mm. Then sand and cement are added in portions to it, everything is thoroughly mixed until the required fat content of the solution is obtained.

2. A dry mixture of sand and cement is prepared in the right ratio. Milk of lime is gradually poured into it, if necessary, diluted with water to achieve the required consistency.

To increase the stability of the solution to environmental factors, slow down the hardening process, the following are added to the finished mixture:

• plasticizers;
• frost-resistant additives;
• setting retarders and others.

The Portland cement used in the composition also brings a number of positive characteristics to the material:

1. in combination with the action of hydraulic additives, it provides resistance to leaching, and therefore to long-term exposure to ground and sea waters;

2. gives cement a high level of anti-corrosion protection;

3. lime mixtures with Portland cement are not prone to destruction even with a seasonal change in freezing and thawing regimes.