Cement mortar is a mixture of mineral fillers, binder and water. It is used in construction work in the construction of various buildings for domestic and industrial purposes.

One of the most important building blocks of any building is the foundation. It can be arranged under a small house in the country and under a huge skyscraper, under an outbuilding in the countryside and under an assembly shop for household appliances.

For most structures, the foundation is located below ground level - hence there are certain requirements for the materials used for its construction:

• the same compressive strength;
• resistance to ground and rain water;
• frost resistance, wide operating temperature range;
• durability.

The types and materials for such structures are different, - one of the types of foundation is a foundation made of brick or stone masonry. This type is due to the impossibility of using concrete, for example, for the construction of a cellar in a rebuilt garage or a country house.

Since such a foundation is equipped with a cement mortar, the general requirements for the foundation will also apply to this mixture.

Foundation Mortar Properties

The mortar used for arranging a brick foundation includes:

• cement brand M-400(PC-400 D 20, - Portland cement with mineral additives);
• quartz sand;
• gravel component with a fraction of particles not exceeding 3mm;
• lime, clay, plasticizers;
• water(rain, snow or water).

The most durable mixture is obtained from cement, sand with the addition of gravel. When building small buildings, gruss is allowed to be added to the mixture for the foundation instead of gravel.

The addition of lime gives the cement-sand mortar greater plasticity and increases the thermal conductivity coefficient.

"Clay" solution has a higher strength than the "lime" one, increases the degree of frost resistance of the liquid solution, which allows it to be used in winter.

One of the important properties of a cement-sand mortar is the ability to retain moisture inside, which goes to carry out certain chemical reactions, as a result of which the cement turns into a stone-like substance.

In addition, water gives the solution plasticity, increases the adhesion of the components of the mixture to each other. Cement mortar for masonry, as well as concrete, has its own brand.

Grades of cement mortar, determination of mixture compositions

The brand of cement mortar is determined through the brand of cement. To do this, the numerical value of the binder is divided by the numerical value of the mass of the sand component of the mixture.

For example, when using a mortar with a weight ratio of cement to sand in the proportion of 1 kg per 4 kg, respectively, and using Portland cement grade PC-400 D20, the number 400 is divided by the number 4, the result obtained, the number 100, will mean the brand of mortar.

In practice, it looks like this: for one bucket of cement, you need to take four of the same buckets of dry sand.

In the presence of a ready-made mixture, it is possible to determine the grade of the solution by knowing the ratio of the components used and the grade of cement, that is, by the reverse action. For example, the proportion was 1:2, that is, two parts of quartz sand were used for one part of M200 cement. The number 200 is divided by the number 2, - the grade of the solution is M100.

When using cement M-400 for the foundation, the consumption of cement per 1 ton of prepared dry quartz sand will be:

Grade of cement	Solution brand
	M 200	M 150	M 100	M 75	M 50	M 25
M 400	450	350	255	200	140	—

Based on the data in the table, to prepare a solution of M 75, it is necessary to take 200 kg of cement per 1000 kg of sand, or 1 kg of cement per 5 kg, or in a ratio of 1:5.

If the foundation is supposed to be erected on dry soils, then lime or clay can be introduced into the solution to increase the plastic properties - then the ratio "cement - lime - sand" looks like this:

Grade of cement	Solution brand
	M 200	M 150	M 100	M 75	M 50	M 25
M 400	1:0,1:2,5	1:0,2:3	1:0,4:4,5	1::0,5:5,5	1:0,9:8	—

To prepare a solution of M 200, you will need 1 part of cement, a tenth of lime, 2.5 parts of sand, which corresponds to: 10 kg of cement, 1 kg of lime, 25 kg of dry sand.

For the construction of foundation structures, concrete pads, a mixture with the addition of gravel or gruss is used.

Their weight ratio "cement - sand - gravel" will be:

Grade of cement	Solution brand
	M 450	M 400	M 300	M 250	M 200	M 150
M 400	1:1:2,2	1:1,1:2,4	1:1,7:3,2	1:1,9:3,4	1:2,5:4,2	1:3,2:5

The foundation mortar M 200 will consist of 1 part of cement, 2.5 parts of sand and 4.2 parts of gravel or 10 kg of cement per 25 kg of quartz sand and 42 kg of gravel, respectively.

To obtain a high-quality reliable and durable building structure, the rule should be applied: "The brand of material used for the construction of the foundation must correspond to the brand of cement-sand mortar."

For example, for a red ordinary brick M 200, a solution of the M200 brand is suitable.

In practice, this corresponds to: 4.5 kg of cement per 10 kg of sand.
If translated into a volumetric ratio, then 3.5 parts of dry sand are taken for 1 part of loose cement.

This ratio is the most optimal - the necessary strength is obtained in combination with an acceptable setting time of the solution.

Thus, using the correct ratio of grades of materials used, it is possible to achieve a monolithic, strong building structure in all directions during the construction.

Preparation of cement-sand mortars

After the calculations and preparation of the components to obtain the solution, the stage of preparing the mixture for the construction of the foundation follows. Mixes are made by means of a concrete mixer or using manual labor.

Using a concrete mixer

1. The final preparation of dry mixes is carried out - sand, gravel or gruss is screened out with a sieve, using screens with different cells, respectively. This procedure will make it possible to achieve a more homogeneous composition in terms of fractionation and thereby reduce the possibility of voids in the finished solution.

   Note. Quartz sand containing significant clay and mud inclusions must be washed. To do this, water is poured into a container with sand, the mixture is thoroughly mixed (“stirred”), after which the contaminated liquid is removed, the sand is dried.

2. Components in the required proportion are loaded into the concrete mixer, where they are mixed in a dry form - the mixture should acquire a light gray uniform shade.
3. After 3 ... 5 minutes of processing the dry mixture in a rotating drum, water is added to the bucket, from an approximate calculation: 1 part of the liquid to two parts of the dry composition.

   Note. The given approximate ratio is valid for dry components. If, for example, wet sand is used, the solution may turn out to be too liquid.

4. To obtain a homogeneous composition the solution is recommended to be subjected to the mixing procedure for 5 ... 10 minutes. In this case, it is necessary to control the viscosity of the mixture:

1. • ready solution should be similar in consistency to toothpaste;
   • placed on a plane, inclined at an angle of 45° to the horizontal, the mixture stably keeps on it and does not flow down, - a mason's trowel or a plasterer's trowel can act as a plane;
   • inscription made on the surface of the solution, should not float.

Properly prepared solution retains its viability for 1 ... 1.5 hours. During this time, it must be developed. When working with several people, it is advisable to distribute responsibilities so that by the time the batch of solution is used up, the next batch is prepared.

The use of cement mortar for private construction

With small volumes of work, and this, as a rule, work on the farm, the cement mortar is prepared using manual labor. The process is almost no different from the mechanized preparation of the mixture, the difference is only in the use of human power.

Since human labor is used, the volume of one batch should not exceed 10 ... 20 buckets (0.1 ... 0.2 m³) of the finished solution, otherwise physical fatigue will quickly set in and there is a risk of losing part of the finished solution.

It is necessary to carefully consider mixing the mixture both at the stage of dry preparation and when mixing with water. With poor preparation of the mixture, the strength of the entire structure will be significantly impaired.

As a container for the preparation of cement mortar, you can use old cast-iron or steel bathtubs, troughs, an iron or plastic barrel cut along.

Water is added gradually, but not less than half at the initial moment. Portions of the liquid are gradually reduced to nothing, as the mixture reaches the required viscosity.

The classic composition of the cement mortar for laying a brick foundation at home looks like this:

• three and a half parts of sifted dry quartz sand;
• 0.8 ... 1 part of water, preferably pipeline.

To increase plasticity, displace air from the solution, improve adhesion, it is recommended to add surfactants to the mixture - surfactants or, in other words, ordinary soap.

For the manufacture of a cement pad under a brick foundation, the following composition is used:

• one part of cement brand M-400 or PC-400 D20;
• two parts of quartz sand;
• three parts of gravel or gruss;
• 0.6 ... 0.8 parts of water.

A pillow for a brick foundation can be arranged from a masonry mixture using:

• waterproofing from roofing felt, greenhouse film, etc. materials;
• construction masonry steel mesh with a cell of 20 ... 50 mm as reinforcement;

At the same time, the height of the walls should not exceed three meters, for example, when building a garage or an outbuilding in the yard of your own house.

The choice of mortar brand for the foundation is determined by the size of the structure being erected, the depth of occurrence, and the materials used. Another important issue is financial costs. But in any case, the quality of the prepared solution will depend on how correctly the components were selected, how carefully the steps for mixing cement-based mixtures were followed.

This article is not for professional builders, they know all this, but for people who are not quite experienced in the profession of a builder, but who decide to independently perform some work that requires cement mortar. Inviting builders is unnecessarily expensive, and it's not easy to find those who want to, if the amount of work is small. And you can prepare a cement mortar yourself.

Some inexperienced developers are baffled by such a concept as the brand of mortar. There is nothing difficult in this. The brand of mortar indicates the compressive strength of a small cube measuring 70.7 x 70.7 x 70.7 (mm) from a hardened mortar and is measured in kg / cm2. That is, the higher the grade of the solution, the stronger the finished product will be. There are only 9 brands of solution, the lowest is 4, the highest is 300. The most commonly used brands are from 25 to 200.

The strength of the mortar depends on the binder (cement) used and the ratio of binder to aggregate (sand). For example, a cement mortar in a ratio of 1:6 means that the mortar consists of 1 part of cement and 6 parts of sand.

Without going into a general educational excursion into the types of solutions, let's go straight to practical advice.

Mortars for masonry walls

When laying walls made of bricks or cauldrons on cement mortar, it is very important that the mortar not only has the necessary strength, but is also sufficiently plastic. Masonry on a hard mortar, which, when leveled on the surface of a brick, immediately gives off water and turns into an inactive mass, looks like torture. When working with such a mortar, the brick does not slip on its surface, the vertical seams are filled very poorly, and there is no need to talk about high performance with such a mortar.

Modern technologies offer various plasticizers, but it is quite possible to do without them, using the old methods of preparing solutions that have been proven for centuries. Undoubtedly, the more binder in the composition of the solution, the fatter it will be, but with this approach, you can come to a catastrophic overspending of cement, and this is money, and a lot of it. Therefore, it is very important to choose the right sand for the masonry mortar.

Very rarely brought sand does not contain pebbles. It is best to immediately sift the sand through a metal mesh with 5 x 5 mm cells for safety net, this will remove not only stones and plant roots from the sand, but also other impurities.

Never use washed river sand for masonry mortars. Only with a cement ratio of 1:3, the mortar can become a little more plastic, but this is already a mortar M 200, and the brand of mortar for masonry is M 50 - 75, the ratio of components in which is 1:6 or 1:5. Quarry sand with a grain size of not more than 2.5 mm, which contains a small admixture of clay, is best suited for such solutions. It is this small impurity that will add the necessary plasticity to the solution.

If you were brought river sand and also coarse-grained, there are two ways to prepare a solution of the desired consistency:

1. Add some clay to it. If you are preparing the mortar with a concrete mixer, then the clay should be thrown into the mixer last. When preparing a cement mortar in a ratio of 1:6, it is enough to add 0.5 parts of clay so as not to reduce the grade of the mortar and make it much more plastic.

2. Prepare cement-lime mortar. The lime will serve as a natural plasticizer that will make the masonry mortar comfortable enough to work with. When preparing such a solution, you can use lime dough or slaked lime, which must be filled with water in a large container. Lime is diluted with water to the consistency of very liquid sour cream and used to prepare a solution instead of pure water. According to the standard for 1 m3 of cement-lime mortar M 50, 150 kg of slaked lime is needed.

The most common brands of cement mortar have the following ratios of cement and sand (the standards are given for cement grade M400):

• M 25 - 1:11 (136 kg of cement M300 per 1 m3 of solution);
• M 50 - 1: 6.3 (232 kg of M300 cement per 1 m3 of mortar);
• M 75 - 1: 4.5 (319 kg of M300 cement per 1 m3 of solution);
• M100 - 1:5 (304 kg of M400 cement per 1 m3 of solution);
• M200 - 1:3 (499 kg of M400 cement per 1 m3 of solution);

Most often, cement M400 is found in stores. But if you come across M500 cement, then it will take less. To determine how much M500 cement is needed, simply multiply the estimated consumption of M400 cement by a factor of 0.85.

In order to determine the need for sand when laying brick walls, you need to know that, on average, 0.24 m3 of mortar is needed per 1 m3 of ordinary masonry, regardless of its brand. Having determined the required volume of solution, multiply this value by 1.2 and get the volume of sand. On average, the weight of 1 m3 of sand is 1.5 tons. From this calculation, you can determine the carrying capacity of the machine needed to deliver sand to your construction site.

The GOST standards prescribe the proportions of cement mortars used for various purposes.

The proportions of the concrete mixture largely depend on the brand, the fillers and additives used, as well as on the type of structure and its location.

In the preparation of a cement mortar for the installation of large-block structures, masonry and other types of work, the ratio of components should be strictly observed.

Varieties of cement mortars:

• masonry,
• plastering,
• facing.

For interlayers and seams, the compositions M150, M300 and M400 are used, for coatings - M200, M300, for screeds it is best to take M150 and M200.

The strength of the masonry and the strength of the structure, as well as the durability of the task as a whole, depend on how well the cement mortar is prepared.

If necessary, the solution may contain additives or be without them, have a thick or liquid consistency.

Cement mortar is produced from the following components:

• cement,
• water,
• sand,
• plasticizers and additives (depending on the requirements for the composition).

With the help of additives, it is possible to obtain quick-hardening, sulfate-resistant, hydrophobic, plasticized, pozzolanic, colored, white and other types of cement mortar. In their production, cement of different grades is used - M100-M600. However, this does not mean at all that in order to obtain a mixture of M400, it is necessary to use cement of the same brand.

In the production of concrete mixtures, the technology of mixing the base material, as well as sand and water in certain proportions, is used.

For example, from cement M400 by adding 4 buckets of sand in a ratio of 1: 4, we will get a brand of mortar M100. To prepare a mortar M100 from M500 cement, instead of 4 buckets of sand, you need to add 5 buckets.

Cement-lime mortar correct proportions

Consider how to prepare a mixture for the construction of ground objects, provided that the relative humidity inside the house is not more than 60%, or for foundations erected on soils containing a small amount of moisture.

With the brand of concrete mortar M10 and cement M150, the proportion 1: 1.2: 9.5 will be applied (respectively - cement: lime: sand), for the mortar M50 and cement M200 - proportions 1: 0.3: 4, subject to the use of cement M400 - 1: 0.9: 8. Obtaining a mixture of M100 (M500) the ratio of components is 1: 0.5,: 5.5, for M150 (from M400) the proportions are 1: 0.2: 3 and for the M200 solution (from M400 cement) - the proportions will be 1: 0 ,1:2.5.

Mortars used in ground structures where relative humidity exceeds 60%, as well as in the construction of foundations on wet soils, will be made taking into account the following proportions:

• M10 from M150 cement - 1: 1: 9, for a mixture of M50 (from M300) the ratio of components is 1: 0.6: 6, for M 100 from M400 - proportions 1: 0.4: 4.5, preparation of a solution of M150 (from cement M500) - 1: 0.3: 4 and for a mixture of M300 (from M400) the proportions will be 1: 0.7: 1.8.

We mix the cement-sand mortar with our own hands

When erecting foundations and other structures below the groundwater level or on soils saturated with moisture, the cement mortar is produced in compliance with the following proportions:

• the brand of mortar M100 from cement M400 and building sand will have proportions - 1: 4.5, for a mixture of M150 (M400) - 1: 3, for a mixture of M300 from M500, the proportions - 1: 2.1.

In more detail, the ratio of the elements of cement mortars is prescribed in tables SP 82-101-98.

It is important to keep the proportions exactly. A lack of sand can lead to a quick solidification of the mixture, and its excess can lead to sprinkling. Water also has a great influence on the characteristics and consistency of the mixture.

Depending on the water content in the cement mortar, they are divided into:

• fatty - there is little water in the mixture, so it quickly hardens and cracks after drying;
• skinny - too much water. Such a mixture may not seize;
• normal - when mixing the components, all proportions are observed as accurately as possible. Such a mixture does not harden quickly and after hardening the concrete does not crack, but has the required strength and reliability.

You can introduce water into the mixture in small portions. It is worth remembering that the difference between low-quality and good concrete mortar is all in 2% of water.

Instead of plasticizers and mineral additives, many builders prefer regular detergent. It provides the mixture with plasticity and makes it more convenient to use.

However, too much detergent can lead to foaming, the solution will become like cotton wool and lose its properties. For one batch, add 50-100 g.

How to prepare a cement mortar

You can mix the components manually or in a concrete mixer. The second option is much faster, more convenient and more efficient. If you plan to prepare concrete solutions in large quantities, you cannot do without a concrete mixer.

Pour clean water, add detergent and start pouring cement and sand (half of the required amount). After the mixture has become homogeneous, add the remaining sand and stir for 3-5 minutes. The result should be a cement mortar without lumps and air bubbles.

If the components are mixed manually, then initially dry cement and sand should be mixed in a separate container, then a funnel is created in it and water is started to be poured in small portions. Stir the mixture to the consistency of sour cream. A clear trace of a shovel should be visible on the surface of the finished solution.

In construction, cement mixture is used for various types of work. It has plasticity, good adhesion, versatility in use. The preparation of the mixture does not take much time and does not cause difficulties. However, it should be understood how to dilute the cement in the correct proportions in order to get a really high-quality building material.

How to correctly determine the brand of the solution

In the construction of any building and during major repairs, cement cannot be dispensed with. It should be borne in mind that the composition of the cement mortar depends entirely on the scope of its application and purpose, and the grade of cement used determines the grade of the resulting mixture.

Before starting work, preliminary calculations should be carried out. The proportions must be strictly observed. Otherwise, poorly done work will have to be redone very soon. It is very easy to understand the basic principles of calculations for self-preparation of a building mixture. The grade of the finished mortar is calculated by dividing the numerical value of the cement grade by the weight of the sand used.

For example, in order to dilute a solution of M100 from M200 cement, it is necessary to take cement and sand in a ratio of 1 to 2. Therefore, 2 buckets of sand should be added to 1 bucket of cement. The mathematical operation is as follows: 200/2=100, where the number 200 means the brand of cement, the number 2 is the number of buckets of sand, and 100 is the brand of the resulting mortar. Similarly, calculations are made with other brands of cement.

Tables of proportions of the main types of solutions

Cement is a binder mortar of a certain brand, where M400 or M100 indicates the load that it can withstand. Instructions for the preparation and use of mortars CH 290-74 has tables with strictly regulated proportions. Mortars are divided into the following types: plaster (M10, M25, M50), masonry (M50, M75, M100, M125, M150, M200), mortar used for screed (M150, M200).

Consumption of cement in kg per 1 sq.m of sand:

Grade of cement	Solution brand
	M200	M150	M100	M75	M50	M25	M10
M500	360	280	205	160	–	–	–
M400	450	350	255	200	140	–	–
M300	–	470	340	270	185	105	–
M200	–	–	–	405	280	155	–
M150	–	–	–	–	–	206	93

In order to increase the plasticity of the solution, clay or lime is added to the building mixture in the following proportions for a foundation in dry soils:

Grade of cement	Bulk composition (cement/lime/sand)
	M200	M150	M100	M75	M50	M25	M10
M500	1/ 0,2/ 3	1/ 0,3/ 4	1/ 0,5/ 5,5	1/ 0,8/ 7
M400	1/ 0,1/ 2,5	1/ 0,2/ 3	1/ 0,4/ 4,5	1/ 0,5/ 5,5	1/ 0,9/ 8	–	–
M300	–	1/ 0,1/ 2,5	1/ 0,2/ 3,5	1/ 0,3/ 4	1/ 0,6/ 6	1/ 1,4/ 10,5	–
M200	–	–	–	1/ 0,1/ 2,5	1/ 0,3/ 4	1/ 0,8/ 7	–
M150	–	–	–	–	–	1/ 0,3/ 4	1/ 1,2/ 9,5

When erecting building structures for foundations and screeds, a mixture of cement with sand and gravel is used in the following proportions:

Grade of cement	Bulk composition (cement / sand / crushed stone)
	M450	M400	M300	M250	M200	M150	M100
M500	1/ 1,2/ 2,5	1/ 1,4/ 2,8	1/ 2,2/ 3,7	1/ 2,4/ 3,9	1/ 3,2/ 4,9	1/ 4/ 5,8	1/ 5,3/ 7,1
M400	1/ 1/ 2,2	1/ 1,1/ 2,4	1/ 1,7/ 3,2	1/ 1,9/ 3,4	1/ 2,5/ 4,2	1/ 3,2/ 5	1/ 4,1/ 6,1

Why grades of material and building mixture must match

To obtain a solid laying of a brick wall or foundation, it is necessary to match the brand of the finished product to the brand of the building mixture. If brick M100 is used during construction, then the mortar must be of the same grade. As a result, the finished structure will be homogeneous and durable.

For great strength when using M350 bricks in construction, it is not necessary to prepare a solution of the same brand; the use of PTS115 will be sufficient. Cement with sand should be diluted in a ratio of 1 to 3.5. even for paving slabs, a solution of 1 to 7 is used.

It is necessary to warn novice masons: it is not recommended to change these proportions. When they are reduced, for example, 1 part of cement to 3 parts of sand, the mixture turns out to be too fast-acting, it becomes impossible to work with it. With an increase in proportions, for example, 1 part of cement to 4 parts of sand, the strength of the mixture decreases, so it is likely to shed.

How to dilute mortar

Mortar can have a different consistency. Cement can be diluted with sand, lime, clay, slag fillers, sawdust and gypsum. You can use such a mixture to fill cavities, fill the foundation, or as a binder. To prepare the solution, you will need water, since cement is used exclusively in a liquid state. After complete drying, the building mixture becomes solid.

• Wall plaster - cement is diluted with sand in the proportion of 1 part of cement to 2 parts of sand.
• The construction of the foundation - crushed stone is also added to the finished building mixture. Proportions: 1 part cement to 2 parts sand and gravel. Note: the number of components may vary slightly depending on the tasks. To obtain high strength, a larger amount of crushed stone is added to the mixture; to obtain a soft and elastic solution, a larger amount of clay is added.
• Water is a very important component of the mixture. The quality of the solution depends to a greater extent on its quantity. Water should be added carefully in small batches, otherwise you can get a product unfit for consumption.

To help novice masons on the construction market, there are a lot of chemical fillers that allow you to achieve the desired consistency of the mixture, and, consequently, the ideal quality of the mortar. Their use does not require professional skills, so everyone can feel like a specialist.

Classic foundation mortar

A concrete mixer is usually used to mix the mortar. The classic recipe for the mixture requires first filling it with water. You should focus on the amount of cement. If 1 bucket of cement is taken for kneading, then the same amount of water is used. To obtain a solution of normal consistency, it should not be poured all at once, it is better to add in small portions. When using wet sand, less water is taken.

Advice from professional masons, popular for a long time. To make the solution more plastic, liquid soap is added to the water. An aqueous solution of soap is more fluid than ordinary water. A mixture prepared in this way better wets the surfaces to be poured and the filler. It is able to penetrate into small pores, therefore, fewer voids and shells will remain in the filled space. The strength and plasticity of the mortar thus increases significantly. When mixing, water and soap must first be combined.

After the liquid soap dissolves and foams, it is necessary to pour in approximately half of the prepared amount of sand. After that, cement is added in full. Some time, approximately 3-5 minutes, is given to mix all the components of the solution, after which the rest of the sand is poured. If the density is unsatisfactory, a small amount of water is added. How to determine the right consistency? The solution in appearance should resemble sour cream, and when you try to draw something on it, the drawing should retain its outlines.

How to dilute cement: proportions and tables updated: June 14, 2018 by: zoomfund

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:

Grade of cement	Consumption of cement per 1 cubic meter sand with mortar brand, kg

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

Mortar grades		Cement costs, kg
		For 1 cubic meter of solution	For 1 cubic meter of sand

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

Grade of cement	Soil type
	low humidity		Wet	Saturated with water
	Cement-lime mortar brand 10 (cement, lime paste, sand)	Cement-clay mortar brand 10 (cement, clay dough, sand)	Cement-lime and cement-clay mortar grade 25 (cement, lime or clay, sand)	Cement mortar brand 50 (cement, sand)

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 be stirred occasionally 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:

The proportion of lime in the solution	Consumption of cement in kg per 1 cu. m solution with a share of sand in the composition of cement-lime mortars