Plastering with cement plaster. How to plaster walls with cement mortar? How to plaster walls with gypsum plaster: video and professional nuances

Cement plaster - traditional, reliable and inexpensive way rough wall decoration, proven time. Construction market overflowing with offers of mixtures for plastering, but cement-sand plaster is still relevant for modern renovation, due to its unique physical and mechanical properties and low price.

In the article we will figure out how to make a mortar for cement plaster, consider several recipes for finishing rooms with different conditions operation, find out how to calculate the mixture per 1 m 2, and give detailed technology work with this composition.

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, they level surfaces, it protects walls from various kinds of damage, it is an excellent heat insulator and absorbs noise well.

The composition of the solutions are divided into:

cement-sand;
cement-lime.

See how the slope plastering is done cement mortar, video tips will help you do the work yourself.

Cement-sand mortars

Cement-sand compositions are used for outdoor and internal works, very durable, not afraid of moisture, temperature changes, durable, the only drawback is that the solution sets and dries for a long time. The main element of the composition is cement - this is an astringent, the brand of which depends on the scope 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 cement mixture, the quality of which depends on the reliability and strength of the solution. It is recommended to use sand of average fraction, fine grains of sand 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 decoration.

In industrial conditions, other components that improve the characteristics of the composition can be added to the finished cement-sand mortar. Additives such as redispersible polymers and copolymers increase the plasticity and strength of the solution, increase adhesion and hydrophobic properties, and frost resistance.

For a layer of cement plaster over 50 mm, a reinforcing mesh is required

Features of the cement-lime composition

Cement-lime plaster, according to regulations, is used only in rooms with a relative humidity of less than 65%. In addition to cement and sand, its composition includes slaked lime, which lightens the weight of the solution, gives it additional elasticity, it sets faster, and it is much easier to work with the mixture.

To prepare a cement mortar with your own hands, lime must be extinguished and kept for about 2 weeks. If you neglect this instruction, then the quality of the plaster will decrease significantly, bubbles will appear during the work, which will lead to a violation of the integrity of the plaster layer. A well-prepared cement mortar with lime paste is vapor permeable and durable.

Ready mixes from manufacturers include the following components:

Portland cement;
slaked lime (hydrated);
quartz sand;
water retention additives;
fiberglass from polypropylene.

Important: Some cement-lime mortars can be used for exterior plastering, usually the manufacturer indicates such specifics on the packaging.

When working with a dry composition, it is necessary to strictly adhere to the instructions, so, with an excess of water. The composition loses its strength characteristics, performance get worse.

Tools for cement plaster

Gypsum plaster or cement plaster, which is better?

It is impossible to answer unequivocally which plaster is better than gypsum or cement, each type of mortar is applicable in its own conditions, and both compositions are often used in repairs. In addition, they have common characteristics:

the closed solution retains its qualities for up to 6 hours;
frost-resistant;
solutions can be applied at a temperature delta from +5 to 30 ° C;
it is possible to putty and paint the plastered surfaces after 2 weeks;
after 3 days, the layer of plaster withstands the gluing of tiles;
it is recommended to store the dry mixture for no more than 1 year, in a tightly closed container, in a dry room.

To decide which is better, gypsum or cement plaster, you should evaluate the area of \u200b\u200bwork, the operating conditions of the surfaces, the purposes for which the surface is leveled. So, it is believed that for wallpapering and painting, it is better to choose a gypsum composition, and in rooms with high humidity, for tiling - cement.

The solution should be thick, stick to the trowel

How to prepare cement mortar for plaster walls

The main components of cement plaster are a binder (cement) and aggregate (sand), in addition, lime, clay, and polymer additives may be included in the composition. The proportions of cement and sand for wall plastering depend on the chosen brand of binder and the area of application of the solution. The finished plaster is obtained from a dry mixture, pouring it with water, the amount of which largely affects the saturation of the solution, and therefore the quality of the finish. Solution types:

fatty - a large percentage of a binder, plaster often cracks during formation;
skinny - a lot of water and aggregate, the plaster layer is weak, it can peel off;
normal - the ratio of sand and cement for plaster is maintained in accordance with the brand of binder and sandstone fraction.

The most popular do-it-yourself recipe, cement mortar for wall plastering, proportions: 1 part cement: 3 parts sand. But the ratio of substances can vary significantly depending on the brand of cement:

M-400 - 1: 8;
M-100 - 1: 2.

PVA added to the plaster solution significantly increases its plasticity, by 10 l ready mix add about 100 ml of glue.

Cement-lime plaster contains lime paste. You can cook it with your own hands, observing safety precautions. The procedure must take place in a metal container, in air, since the quenching reaction releases a huge amount of heat. For 1 kg of lime, 2 liters of water are required. After the mixture has cooled, we filter it through a fine sieve, close the container and let stand for about 2 weeks. Next, mix the solution, if necessary, add water.

Proportions of cement-lime mortar for plaster, in parts:

We offer you a video on how to properly perform cement plaster on aerated concrete.

How to make cement mortar for plaster

The cement-sand mixture for plaster is diluted in a large metal or plastic container, the amount of mortar should be enough for 3-5 hours of work. Dry components are measured in the required proportions, mixed thoroughly and water is added. The mixture should be thick, homogeneous, without lumps, stick to the trowel, for best quality composition should be mixed construction mixer or a special nozzle on the drill.

Consumption of cement plaster

Calculate the thickness of the plaster layer:

clean the surface old finish, remove the weak layer, if necessary, knock down strong irregularities;
we reveal the most convex place, hang the wall, put marks on the ceiling;
in 3-5 places, put the ruler perpendicular to the surface, take measurements of deviations from the plane, summarize, calculate the average;

Wall 8 m2, deviation measurements: (3+6+1+4+1): 5=3 cm average layer of plaster. If you plan to plaster on finished beacons, it is important to take into account the thickness of the guides, from 3-10 mm, depending on the model, we will take 3 mm, we get a plaster layer: 3 + 0.3 = 3.3 cm.

Different types of cement and gypsum mixtures have different consumption per 1 m 2, usually the data is indicated on the package. So, the average is 8.5 kg of dry composition per 1 m 2, layer 10 mm.

Calculations: 8.5 * 3.3 (the thickness of our layer) = 28 kg of the mixture will be required in our case for 1 m2, which means that our wall will be plastered 8 m2: 28 * 8 = 224 kg. In a bag, on average, 30 kg - 224:30 = 7.5 m. This is a fairly large amount, significant financial investments will be required. Home-made cement plaster will cost 2-3 times cheaper, its standard consumption is regulated by SNiP, and is indicated in the tables for different surfaces and application methods. For example, for a porous base made of foam concrete, aerated concrete, the consumption will be greater than for plastering monolithic concrete structures.

Consumption table of cement mixture for plastering surfaces different type, per 100 m2

Do-it-yourself plastering of walls with cement mortar - video and detailed instructions

Before starting work, surfaces should be primed to increase the adhesion characteristics of the finish. Wall plastering can be mechanized or manually and includes several steps:

Spray, layer thickness: on concrete - 5 mm, brick - 7 mm, wood - 1 mm. We wet the wall. We collect a solution of medium consistency in a bucket or pulverizer, throw it on the surface, level it with a rule or a trowel. If further a layer of more than 50 mm is required, we fasten the reinforcing mesh.

Do-it-yourself plastering of walls with cement mortar, on video detailed advice how to spray.

The soil is a thick solution, we collect it with a plaster falcon, we apply it on the surface with a trowel. We wait 30 minutes, level with a long rule, add a solution to the pits, remove the convex places and correct again.
Cover is made liquid plaster mixture, layer thickness up to 4 mm. Moisten the previous layer, apply the solution and carefully smooth it with movements in a circle.

The materials of the video below will tell the secrets of how walls are plastered with cement mortar, a video instruction will help you figure out how to work with the tool.

Plastering walls with cement mortar on lighthouses

We hang the walls, put up beacons: metal, plastic, wire, mortar or drywall. The distance between the guides is less than the length of the rule by 150-300 mm. To increase the adhesion of the plaster to the surface, apply a primer.

Advice: At a time, it is better to pass a plot of 2 m 2, on average, a bucket of mortar goes to such an area.

With a trowel, from the bottom up we throw the solution, a little more than the desired layer, there should be no gaps. As a rule, we carefully lead up and slightly swing from side to side, the second pass of the tool is carried out evenly. We apply the level, there should be no gaps between it and the surface. If necessary, we throw the cement mortar again and repeat the procedure.

For details, see the video on how walls are plastered with cement mortar on lighthouses, a video lesson will help you understand all the nuances of the work.

Plastering is milestone repair, it is necessary to level the walls. Stucco is a convenient way to save time and money during the construction or renovation process. After plastering, it is possible to hide wall defects various types: cracks, potholes, bumps and dents. Plaster is a preparatory layer for fixing facing material. Cement-sand mixture (CPS) for plaster is finished product, which is ready for use immediately after mixing with water.

A mixture of cement and sand: technologies

DSP is available in several types, they differ in the number of additives. For simple jobs a pure composition without impurities is suitable, for other purposes it is better to purchase universal compositions.

Universal cement-sand plaster is used for:

facade works and creation of interiors in any premises;
alignment of the screed or blind area;
improve the protection of the base from moisture.

Any plastering of walls always makes sense

The algorithm of work is always the same, it is carried out in 3 stages:

Black layer.
Ground cover.
Covering, final stage

There is a special high-tech application technique, but it will require special tools. The technology is used in a professional environment, as it is quite difficult to apply and to more used where there is high humidity. Cement-sand mixture for plaster using machines is applicable for facades or large volumes of work, but it is costly. mechanical method requires expensive equipment, it is cheaper to rent an installation.

Features and composition of cement-sand mixtures - what you need to know?

The key features of DSP are increased wear resistance and coating strength. The composition is used for wall decoration from the inside and outside, especially in places with high humidity(bathrooms, rooms without heating, swimming pools, etc.).

In the case of wall alignment with internal defects, the DSP layer improves noise and heat insulation, and also somewhat protects against water absorption. The most important advantage is the low cost due to the use of common materials.

Cement-sand plaster is a mixture different types

Composition of cement-sand plaster:

cement. Various grades of substance from M100 to M500 can be used as a basis. According to the recommendations of experts, M250-M500 is optimally suited for external walls, and internal work is carried out with the composition M100-;
sand. It acts as the main binder, is a filler and a link for cement. The quality of sand directly affects the result: strength, color, reliability, wear resistance. There are two types of sand: river and quarry. At the heart of the DSP, any variant of the middle fraction is used. Professionals prefer river sand.

Traditionally, for the preparation of the mixture, a proportion of 3 parts of sand to 1 part of cement is used. Features of the plaster may vary depending on the manufacturer, since additives are mainly added to the composition: plasticizers, redispersible components, copolymers. These substances improve the strength of the coating, prevent wear, simplify the work with the composition, give the mixture elasticity and flexibility. When working in sub-zero temperatures, in addition to the cement-sand mixture, it is necessary to add aggregators to protect against freezing; ready-made compositions are presented in stores.

What kind of sand is needed for wall plastering: the main recommendations

Sand-cement plaster includes various sand: sea, river or quarry, but there is no unequivocal opinion among builders which one is better. Many people find that using sea sand cement results in a better effect, as it has a more uniform texture. Another argument in favor of the marine look of the material is the absence of any impurities that can damage adhesion.

Here, the opinions of the masters, which is interesting, differ, for example, some pros believe that only sea or river sand can be used.

Facade cement-sand plaster with quarry or river sand costs a little less and has the same performance characteristics.

The ratio of sand and cement

The mixing ratio of the ingredients depends on the purpose. Before, you should clarify the purpose of the solution, the presence of filler and the brand of cement.

More often, sand plaster is mixed in the ratio:

standard mixture: 1 part cement to 3 parts sand;
the use of cement brand M400 or M500 - 1 to 4 or 5, respectively.

The proportions of cement and sand for floor screed are approximately standard. If it is planned to introduce slag or gravel, choose the ratio of cement, sand and filler 1 to 2 to 4-5.

It is important to consider labeling building materials and recommended grades of final formulations. For brickwork, mortar M100-M150 is used, the consumption of cement mixtures is 0.062 m3 / m2. For masonry facing brick M350 use solution M115. Plasticizers are added to increase viscosity. Similar compositions are used in the plastering process for better adhesion.

Proportions are calculated according to desired result and purpose of using the mixture

Varieties of plaster compositions - not everything is so simple

A simple mixture is used in rooms located inside a heated building for:

rough alignment before installing the reinforcing mesh, which must be applied to create decorative variety material;
embedding various defects: cracks, gaps, notches and irregularities. Acts as a preliminary layer for finishing;
creating an antibacterial surface, but special additives are added to the composition to protect against fungus.

A simple composition of sand-cement plaster is used for arranging two-stage system: surface pre-spraying and primer coat.

The composition of the plaster changes if it is necessary to perform work in difficult conditions: high humidity, exposure to ultraviolet radiation, temperature changes. Under these conditions, a universal DSP is used. The characteristic of cement-sand plaster with additives is different due to the increased resistance to negative influences. A universal type of product is used to increase waterproofing, including for reinforced concrete rings, septic tanks, etc.

The universal mixture, with which it passes, is applied in 3 stages (discussed earlier), but 4 steps can be applied to improve the quality (a primer layer is performed 2 times).

A simple composition is used where there is no special importance in the quality of the finish.

If walls with high humidity are plastered, it is recommended to use high-quality compounds that require certain skills and tools. For high quality it is necessary to install beacons, for other plasters they are optional. It is recommended to iron the top layer for waterproofing and increase the surface strength.

Do-it-yourself plaster

If the mortar is to be used for plastering large surfaces, it is recommended to knead the composition on a flat surface with sufficient rigidity, ordinary asphalt will do.

The order of mixing the composition:

3 buckets of clean sand are poured onto the asphalt: without weeds, dirt, stones, dust, shells, etc. It is better to sift the composition first, rinse if necessary.
Align the layer of sand and create a circle.
1 bucket of cement is scattered over the entire area.
After this, it is necessary to mix the composition thoroughly, as a result, no light areas should appear.
The alignment of the material in the form of a circle is performed, most of the DSP is removed from the inside to form a "volcano crater".
A little water is poured into the recess, gradually adding cement and mixing the composition.
After the crater has dried, water is added again until the entire mixture is ready.
At the end, the DSP is thoroughly mixed to create the same consistency.

In the case of preparation for 25 kg of cement, 75 kg of sand and approximately 2 buckets of water are added.

Cement-sand mixture is kneaded on a flat and hard surface

The result of preparing the solution should be similar in consistency to sour cream, but:

for laying tiles on the wall, the mixture is prepared dryish;
if it is planned to use mechanized plaster, the solution is made liquid;
when plastering on beacons, the DSP should not drain and be too dry. Hydrated lime is added to improve elasticity.

Useful tips at the stage of preparation of the composition:

it is important to thoroughly mix the DSP with the water to prevent the appearance of large particles or areas without cement. Due to the appearance of such violations of technology, air pockets or areas with low strength are formed;
for mixing it is better to use a construction mixer, it is inexpensive, but simplifies the mixing process, and also improves the quality of the mixture;
mixing can be done with a drill or perforator when a special nozzle is installed.

Preparation of walls for the application of cement-sand composition

The technology for making the solution allows you to process any surface, but it differs from their type preparatory stage. The composition can be processed:

brick walls;
wooden bases;
concrete facades;
reinforced concrete structures;
concrete houses.

If you are plastering a large surface using beacons, the mortar should not be dry or runny.

For plastering wooden walls, a crate is necessarily mounted, it can be made from slats or shingles. The production metal mesh is easier to install, but the surface is primed first. The crate is a necessary measure for brick walls, only an adhesive is applied on top of them for mounting a metal mesh.

The preparation of concrete walls is the easiest to perform, it is enough to clean and primer. Facade cement-sand plaster is applied to the treated surface using the same methods, but frost-resistant and moisture-proof additives are added to the composition. Despite the relative resistance to temperatures, the application of the composition must be carried out at temperatures above 5°C.

Technology for the use of mortars based on sand and cement

The first stage of application is spraying. A few tips for getting the job done:

the procedure is performed manually using a bucket or trowel. Some novice builders find it more convenient to spray by hand;
suitable for application old vacuum cleaner if it is capable of blowing out air. The vacuum cleaner will replace the spray gun;
The thickness of the layer directly depends on the complexity of the irregularities. In general, on brickwork a layer of 6-7 mm is applied, on reinforced concrete bases - 4-5 mm, and on wood - 1 mm.

The second step is to apply a primer layer. Now it is important to follow the basic recommendations:

To make cement-sand plaster more viscous, special plasticizers are used.

the solution is prepared somewhat thicker than in the spraying process;
it is better to apply the DSP primer in 2 stages;
the first step of the coating is designed to level the base, be sure to wait 30 minutes or more before applying the second layer;
in the second stage, it is important to fill in all visible defects and completely level the surface

Finally, a covering layer with a thickness of up to 4 mm is applied with a liquid solution. If preliminary stages were performed correctly, the covering will not lead to difficulty. To eliminate irregularities, the wall is treated with a grout or half-rubber. During mashing, circular movements are carried out, otherwise noticeable abrasions will appear.

Decorative plaster "Sand whirlwinds"

Today, a new type of plaster is in trend - “sandstorm”. To create a special effect in finishing material add sand. The composition is simply applied to the surface, and the result is a durable, elastic material with protection against air penetration. An added advantage is the absence of solvents and uncharacteristic odors.

The color of the plaster is the most diverse, depending on the design idea. Violet shades are the most popular today.

Plastering walls with cement-sand mortar: 3 important tips

Experts note the importance of 3 tips in which beginners can get confused:

For the preparation of DSP at home, PVA glue is capable of replacing the role of a plasticizer. From 7 to 10 ml is added to 1 liter of solution.
If you plan to spray a smooth surface, the solution may fall off and not adhere well to the wall. Tile adhesive will help improve adhesion. If you want to treat wood and other surfaces with poor cement bonding, it is useful to know what it is.
All substances are somewhat different, it is recommended to study the manufacturer's instructions before mixing. Differences may occur depending on the type of work, recommendations for a specific type are printed on the packaging.

Paint for cement mortar will help improve the appearance of plaster, color will help create interesting design even without a finishing layer.

Plastering walls with cement mortar was the only way to level surfaces in rooms some 20 years ago. But, anyone who has come across such a finish from the "Soviet" times knows how low-quality it is.

However, the reasons are not hidden in the nuances of the material, but in the fact that the technology was kept to a minimum, and the builders did not bother with special alignment. But he has his unique properties, and if everything is done correctly, you can get a decent result.

So, how to plaster walls with cement mortar?

It was the old “Soviet” cement finish that received undeserved contempt among ordinary inhabitants. But, experts know what its advantages are.
Cement-sand mortar creates durable coatings.

The finish is not afraid of water, and dries quickly if wet.
Fire-fighting properties allow it to be used in the repair of facades.
In such a base, the fungus does not start.

The coating is vapor-permeable, the rooms are not completely sealed.
However, to get everything positive traits cement-sand plaster, the technology for preparing the solution, as well as the methods and techniques for its application, should be observed.

What do you need to work

Tools

materials

Lighthouse profile;
Plaster metal mesh (for reinforcement);
plasticizer;
Cement;
Sand.

However, before starting plastering work, it is worth carefully preparing the surfaces, taking into account the wall material.

Plaster work

Preparation of walls for cement-sand plaster

Cement-sand plaster has a significant weight, under the influence of which it can simply fall off from unprepared surfaces. It is with the aim of creating a base on which the entire mass of the finish will hold that they are preparing, but another factor influences here - the wall material.

brick surfaces. The easiest way to make a support for the future applied coating is to equip the crate. Why are nails or self-tapping screws driven in, onto which aluminum wire is wound. If you plan to plaster brick walls small areas, then it is quite acceptable to apply a layer of tile adhesive with a notched trowel, with its further drying.
The most reliable technique is the use of steel plaster mesh.

Block walls. Be sure to prime, and then it is worth covering them with a thin layer of tile adhesive. However, in this case, mesh reinforcement is best.
Shell rock. This material is textured, and “holds” cement-sand plaster well. Before work, you can simply soak it well.

wooden surfaces. It is impossible to plaster wood without reinforcement, the material will simply fall off. Therefore, the planes are necessarily fitted with a reinforcing mesh.

The most difficult thing is to prepare surfaces for plastering in old private houses, where the walls can be stacked with various materials, from clay and raw brick to rubble. Alignment of such walls with cement plaster is carried out at least approximately in terms of level, and reinforcement.

The mesh is made of steel with a mandatory anti-corrosion coating. It is optimal to choose weaving with a cell size of 20 × 20 mm. Fastening is carried out on metal dowels, located in increments of 300-400 mm, and in a checkerboard pattern.

The mesh is slightly pulled over the fasteners, after which the knitting wire must be wound onto the attachment points, connecting them in a zigzag. Individual cuts are overlapped.
When everything is ready, you can proceed to plastering work with preliminary preparation level.

Preparation of plaster

Cement-sand plaster is just a mixture prepared from these ingredients, diluted with water, to which today a plasticizer is added to improve the properties of the composition.
It is necessary to prepare the solution in a concrete mixer, where all the components are well mixed.
But, do-it-yourself plaster for walls is easy to prepare, without mechanization, by kneading using a chopper / shovel. Special attention should be given to the selection of cement and sand. The first one needs a brand not lower than M300, or M400 from well-known manufacturer. Sand is needed only clean river (not quarry!).
The proportions of preparation depend on the brand of cement. When using M300 - 1: 3, and if you knead M400, then 1: 4 (1 part of the mineralite, the rest is sand).
Attention old stale cement should be kneaded in a ratio of 1 to 3!
The preparation is as follows, sifted sand is poured into the concrete mixer, into which cement is added, after which the dry mixture is mixed, and only then water is gradually added. At the end you can add required amount plasticizer. The consistency of the finished plaster mixture should be thick and viscous. With large volumes of work, you should not prepare too much solution, it is optimal to spend it in 1 hour.

Application of cement-sand plaster

It is worthwhile to immediately understand that cement-sand plaster is applied according to the scheme from the bottom to the top!
Before plastering a brick wall, you need to moisten it with plenty of water, or a liquid solution of cement and sand, after which you can proceed directly finishing work performed in three stages.

Throwing plaster mixture on the wall;
Work by rule;
Surface grouting.

Installation of beacon profiles

The beacon profile is a bar made of aluminum or galvanized steel, on which you can set one level for the entire surface during plastering works. Such slats are more modern version lighthouses, earlier, in their absence, they used marks such as blotches from cement, wooden blocks and other suitable materials.

To establish a single level today, laser devices are used, which make it possible to determine the parameters very accurately. But, you can do everything without expensive equipment, especially if you need it at one time.

The most protruding part of the wall is determined, according to its level, and will expose the entire horizon. What can strings be used for? Under the beacons, markings are made, perpendicular to the floor and ceiling. The distance between them is determined relative to the length of the rule, that is, at least 100 mm less from the device.
You can fasten the profiles to the points from the prepared cement mortar, according to which the rails are set with control using the building level.

It can also be used instead of blotches with mortar (putty, tile adhesive), use wooden corks inserted into pre-drilled holes.
When the horizon is set, a cement-sand mortar is prepared for work.

Application of the composition

Simply pick up the plaster mixture handy tool, and thrown onto the surface of the wall, covering it with a layer completely. As a fixture, you can use a bucket or trowel, with which a portion of the cement mortar is brought from the bottom up and thrown at the point with a sharp movement of the brush at an angle of approximately 45 degrees.
With such a simple technique, the entire gap between the lighthouse rails is completely filled with the composition, it is important to reach the level established by these guidelines. If you need to put too thick a layer of plaster, then it is better to do it in layers in two or three stages.

Finishing work

The device is set perpendicular to the beacons, at an angle of 30-45 degrees, and is pulled from the bottom up in a smooth movement. It is important to distribute all plaster mass in a space limited by guide rails, removing unnecessary residues. To evenly divide the entire cement-sand mixture, you can use a slightly zigzag rule.

Having completely leveled the entire area, you can go to the next one located nearby. Grouting is carried out after the mixture has completely dried. Required Tools- half-ter, or trowel board. Detected cracks can be smeared with a solution and rubbed. Subject to the temperature balance in the room, as a result, you can get the perfect surface.

One of the most popular building mixtures, with which the alignment of walls and other surfaces is carried out, cement-sand plaster is considered. This traditional composition is still in demand, despite the emergence of many new plaster compositions.

Features and composition of cement-sand mixtures - what you need to know?

The plaster we are interested in is characterized by high wear resistance and strength. It can be used both for finishing walls inside buildings and for outdoor work (house facades, loggias and balconies). Cement-sand mixtures (CPS) are used for surface treatment in rooms with high humidity. They are also suitable for processing walls in unheated buildings. DSP creates a solid and reliable base on plastered surfaces, on which it is allowed to attach any facing products.

Cement-sand mixture

At the same time, cement-sand compositions perform the function of a heat and sound insulator, limit (to some extent) the absorption of moisture into the treated walls, and most importantly, they have a very affordable cost. The main components of the plaster we are considering:

Cement. To create mixtures, you can use any brand of material (M100–M500). At the same time, experts advise using cement M250-M500 for outdoor work, and M100-M200 for internal work.
Sand. In the mixture, it plays the role of a filler. The strength and reliability of the plaster depends on its quality. DSP is made from river and quarry sand middle fraction. The standard mixture for plastering walls is mixed in a ratio of 3: 1. For every three parts of sand, 1 part of cement is taken.

V last years special components (redispersible substances, copolymers, plasticizers) are often added to cement-sand compositions. These elements make it possible to improve the quality of mixtures by increasing their operational wear resistance, resistance to subzero temperatures, flexibility, and strength.

Varieties of plaster compositions - not everything is so simple

Mixtures of various types can be applied to walls and facades. For example, interior work is usually done with so-called simple plastering. It is used for the following purposes:

Before installing the mesh for reinforcement. It is mounted for applying decorative plaster solutions.
For sealing various defects that walls have (gaps, cracks). In this case simple plaster performs the function of the composition for preliminary finishing work.
As an antibacterial solution. In this situation, cement compositions with special additives that suppress the fungus should be used.

Wall covered with plaster

Simple plaster is used in a two-stage scheme. First, the walls are sprayed with it, and then a primer layer is applied to them. Standard finishing of external elements of buildings and internal surfaces is most often carried out using universal cement compositions. They are also used to increase the waterproofing characteristics of wells made of reinforced concrete rings, household septic tanks and similar structures. In some cases, blind areas and concrete screeds are leveled with a universal solution.

Fits such cement-sand mixture in three stages. First, a rough layer is made. It is called preliminary. Then the wall or other surface is treated with a primer layer. Lastly, the covering is done. This is understood as the careful leveling of the applied plaster by means of trowels, graters and other devices. When plastering walls in damp rooms, it is recommended to use mixtures High Quality. The use of such compositions requires special skills from the performer. The technology of high-quality surface treatment is complex and time-consuming.

Walls are treated with a high-quality mortar in 3-4 stages. In such situations, two primer coats are usually applied. In addition, it is mandatory to iron the cover. This procedure increases the waterproofing performance of the plaster and makes the resulting coating much stronger. Wall plastering with a high-quality mortar is always carried out according to lighthouses. But when working with a universal or simple mixture, they are allowed not to be used.

Preparation of walls for the application of cement-sand composition

The solution described in the article can be processed various surfaces. The technology of their preparation for alignment depends on the type of the latter. If you plan to plaster wooden walls, a crate should be installed on them (it is made of slats or shingles). The second option is the installation of a metal mesh (before this, the surface must be primed). The preparation of brick walls also requires the installation of battens. Then it is coated with an adhesive, on which a thin metal mesh sits. Only after that it is allowed to start plastering the surface.

Easiest to prepare concrete walls. They are cleaned and treated with a primer solution.

Preparing the wall for plastering

Facade surfaces (located outside buildings) are processed according to similar schemes. And they are leveled using cement mixtures with the addition of special components that give the solution additional moisture and frost resistance. The described plaster is suitable for processing reinforced concrete, aerated concrete, wood, brick and concrete facades. Important point! The preparation of external surfaces (as well as their leveling) should be carried out at positive temperatures (5–30°).

Technology for the use of mortars based on sand and cement

The wall is sprayed with a composition that is quite liquid in consistency. The operation is performed manually (ladle, trowel). Many home craftsmen spray the treated base by simply picking up the solution in their hand. Also, to apply the first layer of plaster, you can use an old vacuum cleaner that can function as an airbrush (blowing air through a hose). The thickness of the spray depends on the type of wall to be leveled. Remember the following important numbers. If a brick surface is being processed, a layer is applied with a thickness of about 6-7 mm, reinforced concrete - 4-5 mm, wood - about 1 mm.

Spraying the wall with a cement-sand mixture

The second layer - priming, is obliged by its consistency to be thicker than spraying. Priming with a cement-sand mortar is usually done in two stages. First, the mixture is applied to the surface, trying to evenly "cover" the entire base. The composition is left for 30 minutes. After that, a second pass is made - all visible defects of the wall (facade) are carefully filled and the treated surface is leveled. The covering layer is made up to 4 mm thick, its consistency is liquid. If home master I was able to make the first two layers with high quality, it will apply a coating without any problems. After that, you can start grouting the plastered walls. This procedure is performed with a semi-terre by means of circular movements on the surface.

It is necessary to stir compositions based on cement and sand as carefully as possible. You must ensure that there are no large particles in the ready-to-use solution. Their presence will cause the formation of air cavities on the treated surface, which significantly reduce the strength characteristics of the applied coating. It is best to knead the plaster with a construction mixer. This easy-to-use unit is not expensive at all. And at the same time, it guarantees high-quality mixing of all components of the leveling mixture. Instead of a mixer, some craftsmen use a puncher or an electric drill, making thick wire nozzles for them.

Alignment of the walls is carried out according to the lighthouses and without them. We will not describe these technologies in detail. We only note their main features. involves the use of special guides made of light metal alloys. Their use guarantees obtaining flawlessly smooth surfaces. Novice craftsmen are advised to process the walls precisely according to the lighthouses. In this case, the likelihood of errors in the performance of work is minimized. But more experienced craftsmen produce . If you are not confident in your abilities and eye, it is better not to use this technology.

Now you know all the subtleties of how to level a variety of bases using a cement-sand mortar. Get to work!

Cement plaster is a traditional, reliable and inexpensive way of rough wall finishing, which has proven itself over time. The construction market is full of offers for plastering mixes, but cement-sand plaster remains relevant for modern repairs due to its unique physical and mechanical properties and low price.

In the article we will understand, from cement, we will consider several recipes for finishing rooms with different operating conditions, we will find out how to calculate the mixture per 1 m 2, and we will give a detailed technology for working with this composition.

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 protects the walls from various kinds of damage, is an excellent heat insulator and absorbs noise well.

The composition of the solutions are divided into:

cement-sand;
cement-lime.

Watch how cement mortar is done, video tips will help you do the work yourself.

Cement-sand mortars

Cement-sand compositions are used for exterior and interior work, they are very durable, not afraid of moisture, temperature changes, durable, the only drawback is that the mortar sets and dries for a long time. The main element of the composition is cement - this is an astringent, the brand of which depends on the scope 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 in the cement mixture, the quality of which determines the reliability and strength of the solution. It is recommended to use sand of average fraction, fine sand grains in the composition can lead to after drying, they are added to apply the last thin layer to obtain a smooth surface. Coarse sand is used only in facade decoration.

For a layer of cement plaster over 50 mm, a reinforcing mesh is required

Features of the cement-lime composition

For do-it-yourself lime must be extinguished and kept for about 2 weeks. If you neglect this instruction, then the quality of the plaster will decrease significantly, bubbles will appear during the work, which will lead to a violation of the integrity of the plaster layer. A well-prepared cement mortar with lime paste is vapor permeable and durable.

Ready mixes from manufacturers include the following components:

Portland cement;
slaked lime (hydrated);
quartz sand;
water retention additives;
fiberglass from polypropylene.

Important: Some cement-lime mortars can be used for, usually the manufacturer indicates such specifics on the packaging.

When working with a dry composition, it is necessary to strictly adhere to the instructions, so, with an excess of water. The composition loses its strength characteristics, performance deteriorates.

Tools for cement plaster

Gypsum plaster or cement plaster, which is better?

It is impossible to answer unambiguously which plaster is better or cement, each type of mortar is applicable in its own conditions, and both compositions are often used in repairs. In addition, they have common characteristics:

the closed solution retains its qualities for up to 6 hours;
frost-resistant;
solutions can be applied at a temperature delta from +5 to 30 ° C;
putty and can be in 2 weeks;
after 3 days, the layer of plaster withstands the gluing of tiles;
it is recommended to store the dry mixture for no more than 1 year, in a tightly closed container, in a dry room.

The solution should be thick, stick to the trowel

How to prepare cement mortar for plaster walls

fatty - a large percentage of a binder, plaster often cracks during formation;
skinny - a lot of water and aggregate, the plaster layer is weak, it can peel off;
normal - the ratio of sand and cement for plaster is maintained in accordance with the brand of binder and sandstone fraction.

M-400 - 1: 8;
M-100 - 1: 2.

PVA added to the plaster mortar significantly increases its plasticity; about 100 ml of glue is added to 10 liters of the finished mixture.

Proportions of cement-lime mortar for plaster, in parts:

We offer you a video on how to properly perform cement plaster on aerated concrete.

How to make cement mortar for plaster

The cement-sand mixture for plaster is diluted in a large metal or plastic container, the amount of mortar should be enough for 3-5 hours of work. Dry components are measured in the required proportions, mixed thoroughly and water is added. The mixture should be thick, homogeneous, without lumps, stick to the trowel, for better quality, mix the composition with a construction mixer or a special nozzle on a drill.

Consumption of cement plaster

Calculate the thickness of the plaster layer:

from the old finish, remove the weak layer, if necessary, knock down strong irregularities;
we reveal the most convex place, hang the wall, put marks on the ceiling;
in 3-5 places, put the ruler perpendicular to the surface, take measurements of deviations from the plane, summarize, calculate the average;

Wall 8 m2, deviation measurements: (3+6+1+4+1): 5=3 cm average. If planned, it is important to take into account the thickness of the guides, from 3-10 mm, depending on the model, we will take 3 mm, we get a plaster layer: 3 + 0.3 = 3.3 cm.

Different types of cement and gypsum mixtures have different consumption per 1 m 2, usually the data is indicated on the packaging. So, the average is 8.5 kg of dry composition per 1 m 2, layer 10 mm.

Table of cement mixture consumption for plastering surfaces of various types, per 100 m2

Do-it-yourself plastering of walls with cement mortar - video and detailed instructions

Before starting work, surfaces should be primed to increase the adhesion characteristics of the finish. Wall plastering can be carried out either manually and includes several stages:

Spray, layer thickness: on concrete - 5 mm, brick - 7 mm, wood - 1 mm. We wet the wall. We collect a solution of medium consistency in a bucket or pulverizer, throw it on the surface, level it with a rule or a trowel. If further a layer of more than 50 mm is required, .

Do-it-yourself plastering of walls with cement mortar, detailed tips on how to spray on the video.

The soil is a thick solution, we collect it with a plaster falcon, we apply it on the surface with a trowel. We wait 30 minutes, level with a long rule, add a solution to the pits, remove the convex places and correct again.
The coating is done with a liquid plaster mixture, the layer thickness is up to 4 mm. Moisten the previous layer, apply the solution and carefully smooth it with movements in a circle.

The materials of the video below will tell the secrets of how walls are plastered with cement mortar, a video instruction will help you figure out how to work with the tool.

Plastering walls with cement mortar on lighthouses

: metal, plastic, wire, mortar or drywall. The distance between the guides is less than the length of the rule by 150-300 mm. To increase the adhesion of the plaster to the surface, apply a primer.

Advice: At a time, it is better to pass a plot of 2 m 2, on average, a bucket of mortar goes to such an area.

For details, see the video on how walls are plastered with cement mortar on lighthouses, a video lesson will help you understand all the nuances of the work.