We compare the properties of gypsum and cement plaster: when which one is better to choose, and can it be mixed? Which plaster is better - gypsum or cement? Which one to choose for leveling walls What is stronger than gypsum or cement.

Stucco finish - milestone in carrying out repairs. The quality of its implementation is due to both the professionalism of the master and the choice of mixture. Properly selected solution guarantees the durability and attractiveness of the finishing decorative finish.

There are many types of plaster. They differ in composition, cost, have their own characteristic advantages and disadvantages. Some are time-tested, others have appeared on the construction market recently. The choice of solution depends on many factors. The main thing is their purpose and the quality of the result.

Purpose and types

Plaster mixtures are ordinary and decorative. The first are intended for rough finishing, and the second, produced in various color solutions, are used to create finish coatings. Regardless of the purpose, all solutions are used for:

• surface leveling;
• sealing of vertical and horizontal seams;
• increasing the level of heat and noise insulation;
• creation of effective fire protection.

Classify solutions for plastering walls and ceilings according to the substance that forms the basis of the mixture:

• clay;
• lime;
• gypsum;
• cement.

There are combined solutions and formulations with various additives. Despite the variety of types, cement and gypsum plaster are most in demand. To figure out which of these two types of plaster is better, you need to consider the features of each.

The composition of the solution obtained by mixing cement with lime or sand has undergone significant changes. Modern modifications cement plaster contain various additives that enhance adhesion, plasticity, resistance of the mixture to moisture and other properties.

Cement plaster mortars are used for both external and internal work in order to:

• level the surfaces of the walls and ceiling;
• finishing of unheated or high-humidity premises;
• preparation of surfaces requiring increased frost resistance, for example, a plinth;
• creating a strong and durable coating.

Plaster on cement base, in which there are no additives, can be made independently, and applied to brick, aerated concrete, concrete and other surfaces. To plaster the surface, it is first cleaned of dust and dirt, primed.

Advantages of cement-based plaster

The choice in favor of this material for plastering surfaces is due to the advantages that this type of mixture has:

• strength;
• high level of adhesion;
• low moisture absorption;
• affordable cost.

In terms of strength, cement mixtures have no equal. Experienced craftsmen prefer this surface finishing solution to avoid the need for frequent cleaning. overhaul. High level adhesion does not require the use of means to increase adhesion to the base, allows you to get a layer that retains its integrity for a long time. High resistance to moisture allows the use of cement mortars for surface finishing in rooms with a humid microclimate, in conditions of changing positive temperatures to negative ones. This advantage of the solution is due to its dense structure, in which there are no pores for the penetration of moisture.All components included in cement plaster are low cost and affordable. This was reflected in the final price of finished solutions.

Disadvantages of cement-based plaster

Mixtures, the main component of which is cement, cannot claim to be universal. They, like any other types of plaster, have their drawbacks:

• cannot be used for finishing plastic, wood and painted surfaces;
• have an impressive weight, exerting an additional load on the treated surface, requiring careful conduct calculation required thickness layer before application;
• require large time and labor costs in the implementation of all stages of application;
• need preliminary puttying before staining;
• seized long time which varies from three to four weeks.

The last drawback can be attributed to the plaster, which does not contain modern modifying additives. Solutions from well-known manufacturers on the market building materials and mixtures contain plasticizers, which reduce the curing time of the formed layer of plaster to one week.

To achieve maximum strength and long service life when applying a rough finish, you must adhere to the following rules:

• carry out work at temperatures from +5 to +30 degrees;
• pre-priming the surface;
• apply the next layer after the previous one has dried;
• lay the mixture on beacons;
• start work if there is no experience in applying plaster mixtures, better from small areas.

It is produced in the form of a dry mix, the main component of which is gypsum powder, and additional - various types of plasticizers. To obtain a solution of the required consistency, the plaster is diluted necessary quantity water.

Gypsum plaster is used for interior decoration of ceilings and walls when:

• surfaces are made of concrete or brick;
• prepare for the next decorative trim wallpaper or paint.

Plasters with a gypsum base are not suitable for exterior finish, in high humidity conditions. The mixture can be applied both by machine and by hand. To form a perfectly flat surface, the solution must be applied in one layer. It is acceptable to apply several, but this can complicate the work and increase its final cost.

Advantages of gypsum plaster

The use of this type of finishing solution various surfaces due to many positive qualities, in which it surpasses other types of plaster solutions.

Gypsum plaster has the following types of advantages:

• environmental friendliness;
• plasticity;
• low weight;
• lack of shrinkage;
• finishing speed;
• vapor permeability;
• high sound and heat insulation.

The advantages of gypsum plaster are much greater than those of cement plaster. special attention deserves a cost cut. This is achieved due to the fact that surfaces plastered with gypsum mortar do not need to be puttyed. Surfaces are ready for finishing after setting of the applied layer.

Features of gypsum plaster

The solution is absolutely harmless. A good viscosity index allows you to create a sufficiently thick applied layer that does not deform, does not drain, does not peel off. Gypsum mixtures do not require the use of a reinforcing mesh, which is necessary when finishing the surface with cement plasters. plastic nets reinforce foam and chipboard surfaces. Due to the low weight, the load on the structures treated with gypsum plasters remains practically unchanged. This allows you to reduce the consumption of the mixture, maintain the integrity of the structure, and avoid additional load on the load-bearing walls. The absence of shrinkage allows you to get perfectly smooth surfaces that do not crack when solidified, do not require finishing.The porous structure of the gypsum mixture provides an excellent level of air circulation, preventing the formation of moisture, mold. Surfaces treated with a solution retain heat well, prevent noise and cold from penetrating into the room. The curing speed is 2-3 days or a week if the layer is too thick.

Disadvantages of gypsum plaster

Mortars with a gypsum base are superior in many respects to both cement and clay with lime. These mixtures are practically devoid of disadvantages, but they do have them. The cons include:

• fast grasp;
• high price;
• poor adhesion to metal structures;
• can only be used for interior decoration.

Gypsum plaster sets very quickly and it is not possible to knead large volumes. Fast curing can make the job much more difficult for a beginner, especially when you need to correct "flaws" in the applied layer. The price of the mixture is 1.5-2 times higher than that of cement mortars. This disadvantage pays off with many advantages of the material when carrying out interior finishing and interior work.

The application of building gypsum mixtures has its own characteristics, compliance with which guarantees high quality:

• the solution must be maintained in the desired consistency by adding water to the frozen mixture, if necessary, as the work is carried out;
• it is necessary to prepare fresh batches only in clean containers so that the remnants of the hardened gypsum plaster do not lead to an acceleration of the hardening of the new mortar;
• it is necessary to lay gypsum mixtures exclusively using stainless steel tools so that there are no traces of rust on the finished surface;
• walls and ceilings for plastering must be dry, clean, free from peeling;
• work must be carried out indoors at a temperature of at least +5 degrees.

Which plaster is better - gypsum or cement?

Each solution can be called the best, but only in cases where it is used for its intended purpose, taking into account all recommendations and applications. If the solution is prepared in violation of norms and standards or is expired, it cannot be used. It is not recommended to purchase and stack the mixture when no more than a month is left before the expiration date. Gypsum plaster - perfect option for interior decoration premises. It is easy to use, does not require the master to have experience when working with plaster mixtures. It is recommended to use it in cases where as soon as possible needs to be refurbished and then painted or wallpapered.

Cement-based plaster is suitable for both interior and exterior finishes, with the exception of painted, plastic or wood substrates. It allows you to effectively level the surface. She is preferred for external black finishes and in conditions where the use of gypsum is not possible. It is quite difficult to apply cement plaster on your own without the necessary skills. Work with it is recommended to be trusted by professional craftsmen.

Finishing work on leveling surfaces is carried out various materials. Depending on the location of the surface, the purpose of the room, environment compositions with different properties are needed.

What kind of plaster better fit plaster or cement, should be decided in each case individually. Correctly chosen qualitative composition provide long term service and aesthetic appeal of the plaster finish. How to choose the right solution, what are the advantages and disadvantages of different compositions, we will consider below.

Types of compositions

Plaster mortar has various applications. The most obvious are:

• surface leveling;
• improvement of heat and sound insulation;
• fire protection.

The modern construction market offers different kinds ready mixes for finishing of walls, ceilings, internal and external works. Plaster solutions are divided into 2 groups depending on the application layer:

• regular or basic coverage. It is used when carrying out rough work;
• decorative. Various mixtures to create a finishing finish.

The main way to classify plaster mixtures is the separation of solutions according to the constituent substance:

• cement;
• lime;
• clay;
• gypsum.

Of course, there are various modifications of the compositions, except for the 4 main ones. They are obtained by mixing the main components and adding various additives, additives and plasticizers.

Due to their practical properties, the most popular compositions are gypsum and cement plasters.

Characteristics of the cement mixture

The convenience and optimality of cement plaster is difficult to overestimate; this type of mortar is well-deservedly popular among both experienced craftsmen and novice builders:

1. Coating strength. This is the main quality of cement plasters, the surface is resistant to mechanical stress and reliable.
2. Excellent adhesion. Cement mortars fit perfectly on almost any base, it is enough to treat the surface with a primer.
3. Moisture resistance. Cement plaster is not afraid of impacts precipitation and high humidity, so they are often used in the repair of facades and surface finishing in specific wet rooms.
4. Price. This composition has a quite budget price tag compared to other compositions.

Given that this a budget option, you should not choose a solution based only on the cost of the goods: compare the material consumption and pay attention to the operational properties.

Main disadvantage cement mortar- This is a poor adhesion to wooden, plastic or painted surfaces.

Due to the serious weight of plaster, it is rarely used on ceilings.

For the same reason, the load on the walls of the building during finishing should be calculated.

The plastering process itself is quite labor-intensive, despite the fact that it takes place in several stages, each of which requires a pause in work.

To make the plaster layer as strong as possible and serve long years, you should follow some rules in the work:

• plaster the surface at a temperature of + 5 to +30 0 С;
• be sure to treat the surface with a deep penetration primer;
• to apply an additional layer, you should wait for the previous one to dry;
• carry out plastering work on construction beacons;
• do not take on large volumes if there is no experience in this area.

Gypsum-based mixture

Gypsum plaster mixture consists of gypsum itself and plasticizers. It is applied, as a rule, in 1 layer by hand or by machine. The scope of the gypsum solution is quite extensive, although it has limitations. This type of plaster is used when finishing:

• brick walls and concrete slabs;
• indoor dry rooms;
• for leveling the surface for gluing or painting.

Finishing the surface with gypsum mortar will eliminate the need for puttying work. Quality work with plaster makes the surface absolutely suitable for decorative finishing.

The advantages of working with this type of composition:

The material is warm and dries quickly, it takes a maximum of 3 days to complete the work.

The disadvantages of gypsum plaster include the impossibility of using the solution in rooms with a high level of humidity.

The price tag is slightly higher than that of cement mortars, which is offset by the fact that there is no need to use putty.

Preparation of solutions

It is not enough just to choose a cement or gypsum plaster, for use, it is necessary to properly prepare the solution. Each type of plaster has its own recommendations for the mixing process.

Bulk components of the cement composition are mixed in dry form. Sand and cement are poured in thin layers, and then mixed.

After the dry ingredients are thoroughly mixed, water is added to them. Now the liquid mixture is thoroughly kneaded.

You can also prepare cement-gypsum plaster. This solution will set much faster, drying time will be reduced. But at the same time, the strength of the layer will also change, it will become more fragile. For more information on how to make a mixture, see this video:

Gypsum mortars are kneaded within a short time. It takes no more than 5 minutes to prepare a working portion of the composition. Usually, a gypsum dough is first prepared, which is subsequently diluted with water to the desired consistency.

Our organization offers services for the implementation plastering works . Plastering works are performed mechanically with KNAUF gypsum mixtures. In this article, we advise you to familiarize yourself with the differences between gypsum and cement plaster.

Plasters are the closest relatives of putties. They differ in the type and size of the filler. This determines all other differences, including in the purpose and technology of work. The main difference is that putty can be sanded with abrasive sandpaper, while plaster cannot.

Observing the technology, plasters can be applied in a fairly thick layer. Therefore, traditionally they are used to eliminate significant surface irregularities (for example, plaster on brickwork) or as a necessary structural base (e.g. plaster on wooden bases). As a result, you can get a fairly even, but rough surface (the degree of roughness is determined by the size of the filler grains). Due to the roughness, the use of the plaster layer as a direct base before finishing is quite difficult, and sometimes impossible.
The most effective is the complex use of plastering technology followed by puttying of the plastered surface. In this case, obtaining a perfectly smooth (if necessary, polished) and even surface is achieved in the simplest way.

There are two types of plasters - cement and gypsum. Differences.

The two most common types of plasters are cement and gypsum. From a consumer point of view, their main difference is in the time of complete drying. As a rule, for gypsum plasters it is several days (4-7). Cement plasters require at least 24-28 days for drying and full strength gain.
It is difficult to reduce the time for complete drying of the plaster mixture. The use of special reagents, setting accelerators is advisable only for special types of work in special conditions.
cement plaster It is advisable to apply in the case when it is necessary to obtain the most durable and durable coating. The service life of high-quality and properly executed cement plaster is many decades, even in conditions of temperature and humidity fluctuations.
We note here that for fine leveling of cement plaster, especially in the case of insufficient qualifications of plasterers, it is very effective to use special cement-polymer compounds - levelers. This is a cross between fine plaster and large putty. Fraction (aggregate size up to 300 microns), complete drying time (18-36 hours) and work technology for such compounds as putty (simple application with a spatula, grinding is not required), but they are poorly or not sanded with sandpaper. Such compositions are recommended for use in basements, other utility rooms and for leveling the base before laying tiles. In a word, wherever a perfectly smooth surface is not required and a fine-grained base with a roughness of about 300 microns is quite enough.

Gypsum plasters are preferred in cases where it is necessary to complete the work as soon as possible, subject to further operation only in conditions of normal humidity and only indoors. Gypsum systems have now become widespread both in Russia and in the West precisely because they can significantly reduce the time of work.
We also note that the use of gypsum compositions can significantly simplify the technology. Gypsum plaster can be applied practically in one layer, as opposed to the need to apply cement plaster in three successive layers - spraying, covering and grinding (only this plastering technology is correct).
Since the plaster layer is the basis for all subsequent layers (putty and finishing), it is the "plaster" problems that are the most common cause of cracks in the finishing layer. These problems are the result of either a poor-quality plaster composition (incorrectly selected granulometric composition of the filler, an excess content of clay or organic inclusions, and other factors), or a technology violation. Here the most important points are the prevention of excess water during mixing and the technological expectation of complete drying of the plaster compositions before applying leveling and finishing putties.

General recommendations for the application of plaster technology can be summarized as follows.

1) It is necessary to strictly observe the recipe for preparation and the technology for applying the plaster mixture. For small and medium volumes of work, it is advisable to use ready-made plaster mixtures from trusted manufacturers.
2) In order to avoid the risk that the applied plaster mixture or its components will be of poor quality, it is recommended to use special modifier polymers and (or) reinforcing meshes for plaster.
Modifier polymers are special polymer components that significantly improve consumer properties construction mortar mixtures and intended for direct use on the construction site. The next section is devoted to reinforcing meshes in this book.
3) It is extremely important, as already noted, to ensure that the plaster is completely dry before applying subsequent layers. The simplest and most correct thing is to let the plaster stand for the necessary time until it dries completely.
Artificial acceleration of plaster drying is not very effective and unreliable. The "dryness" of the surface layer of plaster is imaginary and does not guarantee its complete and final drying throughout the entire thickness, and, therefore, not only does not exclude, but even tends to the appearance of cracks. The use of heat guns and drafts does not provide the desired effect. The only more or less acceptable way to speed up the drying of plastered surfaces is deep heating with special infrared heaters. But even such a very expensive solution will not bring significant acceleration. And when performing a high-quality finish, any artificial acceleration is generally not desirable. The appearance of just a few cracks is enough to reduce all the applied efforts to zero.
Only the right decision to speed up technological process, is the application of gypsum plaster. Not forgetting that it is applicable only in dry rooms, with internal works. It is also important to remember that in addition to the simple, internal humidity of the room, it is impossible to prevent the formation of humidity inside the wall due to the lack of its thermal resistance (the so-called dew point). So, for example: the use of gypsum plaster inside country house for non-permanent residence with walls two bricks thick - not acceptable. That is why in each case, when applying gypsum plaster, it is necessary to take into account all the factors and consequences that can lead to an undesirable final result.
In conclusion, it can be noted that there are already gypsum plasters that have a short period of complete drying and are not afraid of changes in humidity and temperature. They can even be used for facade decoration. But these are complex multicomponent and very expensive compositions.
Modern interior systems
NIKPA

As you know, any construction work ends with finishing. One of the stages finishing works in construction is plaster.

Plastering of walls and other surfaces in the room is carried out to give them an aesthetic appearance.

In parallel with this, it is also decided whole line tasks: heat and sound insulation of walls and partitions is increased, protection is made bearing walls from external influences, the hygienic properties of the premises are improved.

Depending on the composition of the mortar mixture, the main types of plaster are distinguished: cement, lime, cement-lime, gypsum or combined.

In addition, there are a number of special compositions (acoustic, heat-insulating, acid-resistant, decorative, etc.). In spite of big variety existing mixtures, the most commonly used in construction are compounds based on cement and gypsum.

However, the choice of one or another type of mixture is influenced by many factors. This is the material of which the plastered surface consists, and the conditions for its operation, and the type of final finish.

In addition, regardless of the material used, plaster is classified according to the quality of execution and can be simple, improved and high quality.

Simple plaster can be used both in utility rooms and in residential ones with further finishing with panels, tiles, etc.

The main filler of cement plaster is sand, river or washed quarry. The binder is cement.

Cement plasters are used when a strong, durable coating is required that resists various kinds of influences. The thickness of such plaster during layer-by-layer application can be any, up to 0.2 m.

The main advantages of cement-based plaster

1. Strength. According to this indicator, all other types of plaster mixtures are inferior. Due to these properties, there is an increase in the strength of both load-bearing walls, partitions and ceilings. This increases the operating time between repairs.
2. Cement plaster has high adhesion. And when applied even on high-strength monolithic structures no need to treat the surface with primers and additives. Accordingly, the plaster layer becomes, as it were, part of the structure, enhancing its strength.
3. Moisture resistance. This indicator allows you to apply plaster at high humidity. high density coating minimizes the penetration of moisture to the structure, thereby increasing the service life.
4. Low cost and availability.

Disadvantages of cement plastering

• Dependence of application on weather conditions. At negative temperatures, it is not recommended to perform plastering work.
• Cannot be used for finishing painted, wooden and plastic surfaces.
• A significant increase in the weight of the structure (walls, ceilings and partitions) due to the large specific gravity the plaster itself.
• Long hardening time of the plaster mass (from 4 to 7 days). This is a factor that affects the construction time in general.
• The complexity of implementation. The process is required to be carried out in three stages: applying the solution to the wall, leveling and grouting.
• The appearance of cracks. When applying plaster of different thicknesses, a thin layer hardens faster than a thick one, which causes surface breaks. This factor is especially relevant when plastering walls with large irregularities.
• The environmental friendliness of such plaster is still in doubt. For this reason, it is recommended to use it mainly for outdoor decoration.

The consumption of plaster per 1 m2 of the finished solution is approximately 10 kg. dry mix when applying a layer of 10 mm.

At self-cooking cement mortar should adhere to the following proportions: for 4 parts of sand 1 part of cement, water is added to approximately the density of sour cream, depending on the thickness of the layer: the thicker the layer, the less water.

Due to low moisture resistance, gypsum mixtures are suitable only for internal plastering.

Although the cost of such mixtures is somewhat higher than cement, however, the speed of work and reduced material consumption, in the end, compensate for this disadvantage by the cost of finishing work.

For the finishing of such plaster, one layer of putty is enough, and with high-quality performance, it can be completely eliminated. Consumption for high-quality plastering is about 0.8-1 kg per 1 m2.

Here, much depends on the qualifications of the specialist performing the work, and the condition of the surface to be plastered. In terms of environmental and many other indicators, gypsum mixtures are significantly superior to cement ones.

The main advantages of gypsum compositions

• No shrinkage when the solution hardens. This indicator allows you to high quality plastered surfaces without cracks and irregularities. There is no need for additional finishing layers. The surface can be obtained ideal in one pass.
• Light weight. This means that plaster has practically no effect on the physical and mechanical properties of walls, partitions and ceilings.
• High plasticity. Allows you to apply layers of any thickness without the mortar running down the wall. Allows mortar to be applied without reinforcing mesh.
• Porosity. Allows ventilation of the walls, which eliminates the growth of mold fungi, etc., the walls always remain dry even with slightly increased humidity.
• The reduced thermal conductivity of gypsum allows you to save heat.
• When plastering with gypsum mortars, the speed of finishing is significantly increased, since the complete setting of the mixture occurs after 2-3 days.

Disadvantages of gypsum plasters

• Gypsum mixtures should not be used when plastering rooms with high humidity, and for exterior decoration.
• When carrying out plastering work on smooth concrete surfaces pre-priming with polymeric compositions is necessary.
• Despite a number preparatory work, when applying plaster on prefabricated reinforced concrete structures factory-made on light aggregates (expanded clay, gas silicate, pumice, calcareous tuffs, etc.), its delamination is possible. This is due to the fact that such aggregates interfere with the drying process of concrete and, as a result, high residual moisture content of the panels.

Regardless of the type of plaster used, the base must be thoroughly cleaned of dust, dirt and grease stains. And if necessary, a notch is made. This is especially important when plastering panels with a gypsum composition.

Also from the video you will learn about the benefits of gypsum plaster.

for alignment and finalization walls, cement or gypsum plasters are most in demand. Both types of material have their advantages and disadvantages, which must be taken into account before starting finishing work.

In this article, we will consider the features of materials and tell you when it is better to use a gypsum-based mortar, and when you can not do without a cement-sand mixture.

What to look for when planning a finish:

• basis for plastering;
• indoor humidity;
• air temperature;
• deadlines for work;
• finishing experience;
• the cost of materials;
• requirements for appearance finished surface.

All plasters according to their purpose are divided into two groups:

1. Ordinary - for leveling surfaces that have defects of various nature and size, significant deviations from the plane.
2. Decorative - for finishing the facade or internal walls, ceilings.

Below we will consider the features of conventional leveling compounds.

Properties of gypsum and cement plaster

The characteristics of cement-sand and gypsum plasters are very different. This is primarily due to the knitting base. Application conditions will be similar - at an air temperature in the room or on the street from +5 to +25 C. Also, the time for complete drying of the solutions is close in value (indoors at air humidity not more than 70%).

The table below shows how these types of plasters differ.

Comparison of advantages and disadvantages

Advantages of cement plaster:

• the solution can be prepared independently;
• not afraid of moisture, does not absorb water, steam from the air, does not change properties when wet;
• resistant to temperature extremes;
• high adhesion (reliability of adhesion to surfaces), including natural, artificial stone, concrete, brick, cinder blocks;
• strength is the highest of all types of plasters, suitability for finishing places with increased operational load;
• the price is the lowest among all plasters;
• universality - suitability for any surfaces, including in rooms with adverse conditions.

When choosing a mixture for outdoor work, it is necessary to pay attention to frost resistance. It is usually expressed in terms of the number of freeze-thaw cycles.

Advantages of gypsum plaster:

• plastic;
• gains strength faster than cement, even when applied with the thickest layer - no more than 1 week;
• easy to apply, just to achieve perfect evenness, no experience in finishing work is required;
• has no shrinkage;
• the color is white, does not show through under the wallpaper or paint;
• surface is smoother experienced craftsmen withdraw finishing layer to the level of putty;
• it is possible to produce three-dimensional patterns and decorative relief;
• light, there is no need to strengthen the foundation and walls;
• does not need reinforcement (if the layer is up to 50 mm);
• vapor permeability - walls plastered with gypsum mortar "breathe";
• higher sound and heat insulation properties;
• less material consumption;
• faster repair times;

Let's continue the comparison finishing materials and consider their weaknesses.

Disadvantages of cement-sand plaster mortars:

• poor adhesion to wood, paint, ceramics; to increase adhesion with these materials, an abrasive primer, notches or reinforcing mesh are required, but these measures do not always give the desired strength;
• take a long time to gain final strength - up to 4 weeks;
• the application process is relatively complex, the solution under its weight is prone to sagging; experience with such material is necessary, otherwise it will not be possible to achieve a perfectly flat surface;
• the finished surface is porous, requires grouting, grinding, an additional finishing layer from another material (this does not apply to decorative plasters);
• an accurate calculation of the load on the wall and foundation is necessary, since cement plaster has greater density and significantly weights the walls; it is also undesirable for finishing ceilings;
• shrinkage, possibly cracking.

Most of these disadvantages can be corrected by adding modifying additives - plasticizers to the composition.

The addition of lime also improves the properties of the mortar. Read more about cement-lime plaster and its properties in our article.

The appearance of cracks is prevented by applying three layers or puttying the plastered surface. If the cement mixture is used to decorate walls and ceilings for painting or wallpapering, then puttying is required.

Disadvantages of gypsum plasters:

• they are afraid of high humidity, upon contact with water they swell and fall off;
• low strength;
• relatively high cost;
• mainly used ready-made gypsum mixtures, for self-selection gypsum additives and their proportions require experience;
• it is possible to prepare the solution only in small portions due to the rapid setting, the addition of water to the solidified mixture will not restore the desired properties of the plaster, the coating will turn out to be fragile.

Where applicable

Cement plaster is used for:

• internal or external works in any premises, even in unheated and damp ones, including basements, utility blocks, garages, entrances, on balconies, loggias;
• finishing facades, plinths, fences, especially those subjected to aggressive mechanical stress;
• filling joints when laying walls from foam or gas blocks;
• processing concrete structures, in order to improve the heat-insulating properties;
• restorations subject to compatibility with the previous material;
• surface finishes exposed to temperature changes;
• decoration of walls or ceilings where frequent repairs are impossible.

Gypsum plaster is used for:

• leveling, finishing interior walls in rooms with normal humidity;
• ceiling decoration;
• alignment of walls with large differences, application in several layers is permissible;
• surface finishes for which cement is unsuitable - wooden, painted, ceramic;
• preparation of walls and ceilings for painting or wallpapering.

Important! Gypsum mortars are not suitable for finishing the facade due to low moisture resistance. Not recommended without additional waterproofing for bathrooms, showers, kitchens.

You can protect gypsum from moisture by applying an acrylic primer. And if direct contact with water is possible, then the walls are covered with waterproofing mastic or tiled.

Combination of gypsum and cement

Can gypsum plaster or putty be applied over cement plaster? Yes, this is common practice. When finishing, the walls are often removed with a cement-based composition, and a smooth finish layer with Rotband is placed on top.

Important conditions: you need to wait until the base dries, then be sure to apply a primer between different layers.

But the application of cement plaster over plaster wall- bad idea. Plaster simply will not withstand its weight, and the entire finish will crumble.

It is worth noting that cement-gypsum compositions are on sale., combining the advantages of both types, for example, Prospectors MIXTER / MIXTER. According to the manufacturer, this gypsum-cement plaster is designed to interior spaces with normal and high humidity. This is a moisture-resistant vapor-permeable material, plastic and easy to apply.

Technical characteristics with this mixing turned out to be average between gypsum and cement plaster:

• Consumption with a layer of 10 mm - 10-11 kg / m2
• Water consumption - 0.36-0.42 l / kg
• Setting time - 40 min
• Adhesion to the base - 0.5 MPa
• Layer thickness - up to 60 mm! without the use of plaster mesh
• The price is 320 r per bag of 30 kg.

In addition to the main components, this mixture includes a light filler and high-quality modifying additives.

Is it possible to mix cement and gypsum plaster on my own to get a plastic, durable and moisture resistant solution? No, that won't work. Gypsum and cement have different time drying, and if they are mixed by eye and without the addition of modifiers, then the plaster layer on the wall will become covered with cracks. It is better not to experiment with such works, so as not to waste time and money.

Let's summarize which one is better.

• When choosing one or another type of finish, consider in which room the work will take place. Materials according to their characteristics must be suitable for the surface to be plastered.
• Pay attention to specifications indicated on the packaging.
• If desired, you can increase the plasticity of the cement or moisture resistance of the gypsum plaster mixture.
• Cement mortars are best chosen for the facade and wet rooms. But they require plastering skills. At large volumes work is easier if experienced craftsmen do the finishing.
• Gypsum plasters are easier to apply. Their main task is finishing inside the building.
• The cost and planned timing of repairs will also affect which plaster to choose.

As you can see, the choice of plaster depends on specific goals. Choosing one type of plastering or using both is decided in each case individually.

We hope this review was helpful to you. You can leave your comments and feedback in the comments below.

Types of plaster Wall plastering with lime mortar: lime slaking, mixture proportions, application