A mixture of cement and gypsum proportions. Which plaster to choose - gypsum or cement? Comparison of advantages and disadvantages

Low cost plaster

in the construction of dwellings, gypsum mixes have been used for many centuries. Ancient civilizations left us many architectural monuments, which were widely used Construction Materials based on gypsum binders.

The use of compositions based on cement and gypsum is due to the mass positive qualities, which are characteristic of this particular group of binders. They practically do not precipitate during hardening, quickly gain strength when solidified, gypsum materials have impeccable sound-proofing and heat-resistant qualities, good fire resistance, and, most importantly, this is an environmentally friendly composition.

Low cost plaster

Especially important is the use of mixtures based on gypsum and concrete for Russia in the construction and decoration of buildings and structures because: the lion's share of all the planet's reserves of natural gypsum is concentrated on Russian territory; the price of manufacturing a gypsum binder is very low (5 times) compared to the price of cement manufacturing; energy costs in the manufacture of 1 ton of gypsum are 3-6 times lower than in the production of a ton of cement.

Why Should You Use Supplements?

Despite the age-old experience of application and the abundance of positive qualities possessed by dry mixes of concrete or gypsum, these finishing materials are used in Russia only for plasters and putties on premises. The reason for this was low water resistance and low strength characteristics, since gypsum dissolves quite well in water, and when hardened, it has a high porosity. But, the solution to these problems was found. To eliminate such shortcomings, additives are used that, when interacting with gypsum, form compounds with lower solubility.

Modifiers

One of the ways to solve problems with the strength and water resistance of concrete and mortars based on gypsum concrete binders is the admixture of a special kind of impurities - modifiers.

Modifiers are a carefully selected combination of organic and mineral components, which are first subjected to special processing and optimized in composition. With the help of these dry modifiers, formations become more water resistant, a denser structure is formed. Thanks to such modifiers, the mixtures not only increased their compliance sanitary requirements, but also significantly improved moisture resistance, increased the speed of curing materials.

Quality improvement

The combination of these properties provides the following benefits:

• increases the energy efficiency of buildings, due to a wide range strength characteristics, water resistance and frost resistance;
• use materials based on which modified gypsum can be used not only as finishing materials in residential premises, in buildings for various purposes and number of storeys, in enclosing, load-bearing structures;
• no need to use heavy construction equipment;
• construction time is reduced several times, and the initial cost of construction is significantly reduced.

Application

To date, dry modified mixtures based on gypsum and cement are the most popular in comparison with a number of other finishing materials. Dry modified mixtures are used in leveling walls, ceilings, flooring, in tiling, masonry work, as well as used not only for puttying and plastering, but also as tile adhesive, self-leveling floors, etc.

Thus, if we take into account the many shortcomings in the cement industry, and these are inflated prices for Portland cement, and the shortage of its supplies, then the use of mixtures based on gypsum and concrete with the addition of modifiers is the best choice in the range of finishing materials.

You have decided to repair the house with your own hands, or to carry out primary finishing in a new building, and you don’t know which plaster to choose: cement or gypsum?

Before a decision is made, you should familiarize yourself with the characteristics of modern building mixtures. We will bring to your attention comparative review various types of solutions, and we will tell you where and how they can be applied. The video in this article will help to understand this issue.

If we talk about building mixtures in general, then they are, first of all, classified according to their purpose.

These are the four main groups:

• Masonry mortars for installation works
• Facing (adhesive) solutions
• Plaster mixtures
• Decorative and special plasters (see Decorative plaster in the interior: beautiful, stylish, non-standard)

According to the component composition, they can be simple, based on a binder of one type, and complex, where there are at least two binders. Thinking about which plaster is better: gypsum or cement, many do not even realize that there are also cement-clay and cement-lime mortars, as well as mixtures based on lime and gypsum (see Types of plasters for interior decoration: choose the right one).

• In large-scale construction, such plasters are most often used. They are made at on-site puttying stations, or delivered to ready-made from the nearest mortar-concrete unit. In the process of preparing the solution, additives are introduced into it that provide certain characteristics, and the formulations are quite complex.
• It is almost impossible to make such a solution on your own, therefore dry mixes already balanced in terms of components are produced for private construction. In production, their compositions are modulated with the help of polymer additives, which makes it possible to obtain a material with desired properties. The more complex the composition, the higher the price of the material, and this is quite understandable.
• Factory mixtures have an undeniable advantage: just add water, as the instructions say, and you can work. It is convenient to mix a small amount of the solution so that one person can work it out quickly. And yet, the use of ready-made mixtures allows you to avoid mistakes in the recipe of each batch, and for those who plaster walls and ceilings on their own, this is the best option.

• Finishing plasters are divided into two categories: leveling mixtures and mortars with decorative effect. Each of these categories may differ in composition, depending on the purpose: for facade (see Facade plaster for foam plastic or foam plastic) or for internal works.

There are options that, due to the presence of silicone, acrylate resins, or polyurethane, are considered universal, and can be used both outside and inside buildings. They are called polymer cement or gypsum polymer, or simply modified, and you see one of these options in the photo above.

Requirements for finishing mixes

As you can see, there are many recipes for plaster mortars, and to answer the question: “Which is better: cement or gypsum plaster?” - not as easy as it seems. Naturally, the characteristics of the solution are determined by its purpose, but there are requirements that all finishing compositions must meet.

So:

• First of all, it is the appropriate mobility and high adhesion. In addition, it is necessary that the solution retains its volume when dried. That is, to avoid cracking of the screed, the plaster must be non-shrinking.
• The degree of mobility of the solution may vary, depending on the fraction of the filler. For example, machine application mixes may be less mobile than hand plaster solutions.

• Gypsum plasters should be the most mobile; for this, organic plasticizing additives are added to them. Gypsum-based solutions set very quickly, so the timing of their hardening also needs to be regulated. As in the case of mobility, this is achieved by introducing special additives into the composition.
• Decorative plasters are distinguished by the highest plasticity, because such a composition must not only be applied and leveled, but also have time to mechanically process the covering layer before hardening.
• In their production, white and colored Portland cements are used, if these are compositions for exterior finish, and gypsum, if the plaster is intended for interior work. Lime can be introduced into both mixtures - for example, if they are intended for plastering walls made of silicate concrete.

In finishing plasters from organic fillers, only sand is used. As for decorative solutions, depending on the effect, they may contain crushed glass or mica, marble or granite chips, crushed limestone, dolomite, as well as artificial and natural pigments.

Application of plasters

Cement-based mortars are the most durable, and when dried, they form a stone that is practically not susceptible to moisture. That is why they are used for plastering facade walls, as well as premises with increased level humidity. Purely cement mortars are not very plastic, therefore lime or polymer additives are introduced into them.

• Lime-cement and lime-gypsum mortars are good for plastering wooden surfaces. Polymer cement compositions are ideal for systematically wetted structures. So, if you need to make protective plastering of the basement walls - this is the best option.
• Inside the house, such compounds are used only for leveling walls in bathrooms. In other rooms, they are recommended to be used only for making a leveling screed for cladding. ceramic tiles or natural stone. This is important, because the strength of the base must always be higher than the strength of the coating.

In other cases, for interior decoration residential buildings and apartments use gypsum-based solutions, and reader interest in them is the highest. For this reason, we will pay more attention to the question in which situation and which gypsum plaster to choose in order to make the leveling at the lowest cost.

Varieties of gypsum compositions

So you went to hardware store purchase necessary material. You have a considerable assortment in front of you: gypsum plaster - which is better? Let's look into this issue together.

The main criterion for selecting a variant of the plaster mixture is the quality of the base. So before you go shopping building mixtures, the condition of the surface to be plastered must be assessed.

• To do this, you first need to clean it, if it is a repair, or immediately carry out hanging, if it is a primary finish. This will make it possible to calculate how thick the screed should be, and accordingly, decide which gypsum plaster is better.

This does not mean products under a certain brand, but the physical and mechanical properties of the mixture, which are declared by this manufacturer. So, the best gypsum plaster is the one that answers specific task, in which there are two main conditions: the type of surface, and the dimensions of its deviations from the plane.

Plasters for different types of surfaces

When it comes to apartments, most often the walls in them are either built from large panels, which are made from heavy concrete, or it is masonry from silicate - less often, red brick.

So:

• In private houses and cottage construction, blocks of lightweight and cellular concrete are often used. They are also used in the construction of multi-storey frame-type buildings. In them, the frame bears the main load, and light blocks of a small format are very convenient for the construction of enclosing structures.
• Of course, for the choice of plaster design features buildings play no role. But it matters what kind of filler is used in the production of concrete blocks from which the walls are built.

• For polystyrene concrete, gas silicate blocks and foam blocks, special plasters are provided (see How to plaster foam blocks according to technology), which provide increased adhesion and vapor permeability of the screed. In principle, for plastering such surfaces, adhesive compositions used for masonry work can be used.
• They are called so: adhesive plasters, and they are always made on the basis of cement. Gypsum-based compositions are used only for plastering, since they are not suitable for masonry and installation work. at the expense a large number pores, which can be both closed and open, cellular concrete intensively pass moisture and air.
• In the compositions for their plastering, perlite is often present - an organic filler, which, due to its low thermal conductivity, belongs to the category thermal insulation materials. Perlite granules partially close the pores on the concrete surface, while allowing the walls to “breathe”.

In general, for plastering such surfaces, lime-cement and lime-gypsum plasters are simply ideal. Technology for the production of plastering works concrete base with a cellular structure, also has its own characteristics, but this is a completely different topic.

For interior decoration of walls made of brick and heavy concrete, any gypsum plaster compositions are suitable, and not only gypsum ones.

Interior work: why gypsum mixture is better

Gypsum-based compositions are preferred due to white color. For interior work, they are mainly used water-dispersion paints, but they do not have such high hiding power, as, for example, oil paints, or alkyd enamels.

This means that in order to paint over a dark cement screed, you will have to apply large quantity layers, which leads to waste of material.

• Even when wallpapering, cement plaster can shine through a thin light-colored canvas, and spoil the whole aesthetics of the finish. For this reason, when leveling indoor walls, cement-based compounds are used only for tiling.

• And one more important nuance. Many readers are interested in: "How long does gypsum plaster dry?". Of course, this depends on the thickness of the layer and the temperature in the room. But in any case, the gypsum screed will dry twice as fast as the cement screed. In the first case, a layer of 1 mm hardens in 4-5 hours, in the second case, it will take 8-10 hours.

The answer to the question: "Gypsum plaster: how long does it dry?" - quite simple. In practice, each coat usually takes at least 12 hours to dry. That is, during the day a layer of plaster is applied, for example, 2 mm thick - it dries out overnight, and in the morning you can safely continue work.

If the irregularities of the base base are such that it is necessary to plaster with a thick layer of 15-20 mm, then it may take at least 3-4 days to dry.

Selection of plaster according to the quality of the base

Gypsum plaster: which is better? Which option to prefer if the walls are relatively even, and which one if it is crooked brickwork? In this part of the article, we will discuss the principle of selecting a mixture according to the quality of the base.

• If the walls or ceiling do not have significant deviations from a single plane, it is enough to putty small cracks and surface shells, and then apply thin layer one layer of plaster.

• According to this principle, walls are plastered in panel houses, is done redecorating old, but still strong plaster, as well as preparation for painting surfaces, leveled in a “dry” way - using drywall.
• For such walls, gypsum-polymer compositions are usually used that do not require puttying. Due to their high plasticity, they have excellent adhesion, and are suitable for plastering almost all surfaces, even foam concrete walls. In any case, you need to read the manufacturer's instructions, where the purpose of a particular composition, as well as the thickness of the applied layers, are clearly regulated.

• Everything related to masonry: even brick, even block, does not look so optimistic. Walls built from blocks are even more or less even. But brickwork rarely boasts high quality, because, as a rule, everything goes into work: bricks with potholes, chipped corners, cracks.
• Therefore, even if there are no bumps and large recesses in the masonry, there are still many other shortcomings that have to be eliminated during the plastering process. To align such walls, you have to use compositions with different fractions of the filler.

• Starting, or, as they are also called, base plasters (putties), have a coarser dispersion, and are applied with the first layer on the wall treated with a primer. This layer has the greatest thickness, and is designed to hide the largest defects in the base.
• If the depth of the recesses exceeds 2 cm, and this happens quite often, the alignment can be done in two layers, between which a reinforcing fiberglass mesh is mounted.
• Since the components of the base putties have a rather large dispersion, the surface of the screed is grainy, and a finishing composition is used to smooth it out. Its ingredients are finely ground, so the dry mix is ​​more like a powder.
• The finishing plaster solution is extremely elastic, and when applied to the starting screed, it fills the smallest pores and cracks in it. Thus, the surface is brought to perfect smoothness.

Finally, we recall that it is better to purchase mixtures of "start" and "finish" from one manufacturer. In this case, you can be sure that their compositions are maximally adapted to each other, and they will not create any problems in the work.

If you need to level the surface of the walls in the room or update the facade of the house, wall plastering is one of the most inexpensive and popular ways. Of course, getting started, you must first familiarize yourself with the types of plaster (especially when repair work there is not enough experience), because choosing the wrong mixture can ruin the final result. In this article, we will tell you how to prepare a cement-based plaster mixture and dry gypsum plaster, as well as which type is suitable for walls.

Wall plaster

Comparative characteristics of plaster mixtures

Let's compare cement-sand, lime and gypsum mortar for plastering walls according to their characteristics.

Gypsum plaster

The most popular now are dry mixes for gypsum-based plaster. Their main advantage is a very simple application process. Such plaster is sold ready-made, you don’t have to mix anything, you just need to dilute it with water in the required proportions.

The most popular plaster mixture is from Knauf-Rotband, Volma Sloy, Forman 10, Founding Gipswell, Prospectors. In terms of quality, they differ little from each other, but some types cannot be used in wet areas.

"Knauf Rotband"

Separately, it is worth talking about universal mixtures for wall plastering from Knauf - Rotband. The price for a bag of 30 kg is 360-390 rubles, which is more expensive than all similar options. On sale there is also packing of 5, 10, and 25 kg.

This mixture has been produced for half a century in Germany, and in Russia it appeared 20 years ago. It has become so popular that the name "Rotband" is used by some to refer to any dry gypsum plaster mixes.

There are other gypsum plasters from Knauf-Goldband and HP START, but they are not in demand due to their high density.

"Rotband" has the following characteristics:

• Consumption 8.5 kg/sq. m. with a layer of 1 cm. One standard bag is enough to level 3.5 sq. m.
• The maximum layer thickness is 5 cm (on the ceiling only 1.5 cm, and if the height difference is greater, then alignment is done using suspended ceilings).
• The minimum layer thickness is 0.5 cm (1 cm when laying tiles).
• The average drying time is 7 days, depending on humidity and thickness.
• Suitable for plastering walls and ceilings made of concrete, brick, polystyrene foam surfaces.
• This mixture is not suitable for sealing joints between drywall sheets. For this, gypsum-based putty is used - " Knauf Uniflot". Read more about drywall puttying in our article.
• Recommended for use in rooms with normal humidity air, can be used in the kitchen or in the bathroom.
• Color - from white to gray or even pink. It depends on the amount of natural impurities, and does not affect the characteristics of the material.
• Shelf life - 6 months.

Apply over thick layer on walls it is possible after full drying of the first layer of the maximum thickness. On the ceiling, applying more than one layer of plaster is unacceptable.

Among the main advantages of the mixture "Rotband" are the following.

• Getting a smooth surface.
• The absence of cracks even on a thick layer of plaster (subject to compliance with the technology).
• The consumption of the mixture is two times less than that of cement-sand types.
• Possibility of applying a layer up to 5 cm in one go without splashing the surface.
• The solution does not lose all moisture even on porous substrates or at elevated temperatures, which ensures uniform drying without delamination and without cracking.
• The composition does not contain harmful substances, completely safe.
• Due to the addition of polymer additives to the composition, the mixture provides enhanced adhesion, which allows it to be used even on the ceiling.
• The composition of the mixture includes special additives to increase the working time with gypsum mortar.

To obtain the optimal consistency, the dry mixture is mixed with water in proportions of approximately 2: 1, i.e. 15-17 liters of water should be used per 30 kg bag. For thorough mixing, use the mixer nozzle on the perforator.
The video shows an example of plastering work using Knauf Rotband:

Cement plaster mixture

The cement-sand mixture for plaster has the following composition:

• 1 part of cement m-400;
• 3-5 parts of sand (if the cement is m-500, then you can increase it to 7 parts of sand).

Usually, when cooking, all the elements are added “by eye”. You can use the following instructions.

• The preparation of a solution for plastering walls begins with sifting sand. This will require a sieve with cells of about 4 mm; for dry sand, a finer mesh can be used. When the sand is ready, proceed to the manufacture of the solution. To do this, pour 2.5-3 liters of water into a 10-liter bucket.

To make the solution soft and plastic, you can add a little detergent to the water.

• Put three parts of cement into the mortar container and mix it thoroughly with a mixer.
• While mixing the solution with a mixer, add sand until the container is full. Start stirring the solution at low speed so that the liquid does not splash out.
• As a result, the solution should turn out to be a viscous consistency, so that when the mixer is pulled out, a hole of 2-3 cm remains.

One batch is enough for approximately 1.5 square meters of plaster. m. walls. Basically, the consumption of the mixture depends on the thickness of the applied layer, so if you want to avoid overspending the material, then you need to buy the thinnest beacons, from 3 mm.

Dry mix cement based

If there are no plans to mix the solution yourself, you can buy a ready-made mixture in dry form, which is simply diluted with water.

For example, the following types are on sale:

• "Vetonit TT";
• "Volma Aquasloy";
• "Magma";
• Plaster and repair putty "CeresitCT 29";
• For facades: Knauf Unterputz, Sokelputz, Grunband (with expanded polystyrene granules), IVSIL GROSS.

Cement-lime mixtures

Cement mortar in its pure form is not used so often, because it has poor adhesion and increased cracking. In addition, not everyone has the opportunity to use expensive dry mixes, so plaster is a good alternative. lime mortar. This is very economical option a mixture with which it is convenient to work due to its plasticity.

Also, this option is good for use in private homes due to bactericidal properties - this is an additional protection against fungus. Lime mortar is chosen mainly for rough wall finishing in rooms with normal and low humidity. Unlike cement mortar, a lime-based mixture is well suited for plaster over shingles, as it adheres well to a wood surface.

The disadvantages of this mixture include low grade strength, in contrast to the solution based on Portland cement. But this drawback does not play a special role; for plaster, compressive strength is not so much important as good level adhesion and plasticity.

Composition of lime mortar for plaster:

• 1 part cement;
• ½ part of slaked lime;
• 5 parts of sand;
• 300 ml liquid soap.

The mixture turns out to be very elastic and keeps well on the wall; after drying, cracks do not appear on the surface. Liquid soap adds a pleasant smell and increases elasticity.

Cement-lime mortar for plaster can be prepared in another way:

• 1 part lime sour cream;
• 2.5 parts of sand;
• 0.12-0.25 parts of cement (depending on the amount of lime).

Best to take quicklime and extinguish it yourself. 50 kg will require 13 buckets of water. Please note that lime will increase by 2.5-3 times during slaking, so this work is done in a barrel of the appropriate volume.

This composition will adhere well and keep on the wall, level with the rule and rub well. Plastering costs 250 sq. m. such a mixture will cost about 22,200 rubles. (per material):

• 3 cubes of sand - 2000 rubles;
• quicklime 800 kg - 19,000 rubles;
• cement 150 kg - 1200 rubles.

If we compare the costs with the Rotband plaster, then the same area would take 3-4 thousand rubles more.

Dry mix based on lime-cement

You can purchase a ready-made dry mix on a lime-cement basis.
The most popular types are:

• "Knauf Sevener" (universal mixture);
• "BEST";
• “Founding STARTWELL” and “FLYWELL”;

Facade plaster mixes

In private houses, in addition to interior decoration, it is required exterior finish walls. Many owners unknowingly or for the sake of economy plaster facades with the same mixture that was used for interior decoration. It is strongly discouraged to do this, because for external walls requires a mixture that can withstand exposure environment and yet not collapse. Below we give a list of good plaster mixes for facades.

Mineral plaster mixes

Mineral mixtures are produced on the basis of cement, therefore, there is a marking on the packaging - “Polymer-cement mixture”. Thanks to such a component as a redispersible powder, these mixtures have high adhesive qualities. sell mineral mixtures dry in bags.

mineral plaster
Specifications:

• low cost;
• resistance to fire;
• moisture resistance;
• good strength;
• high vapor permeability;
• long-term operation.

Acrylic-based plaster mixes

Synthetic plaster mixes are made on the basis of acrylic dispersion. Sold ready-made liquid state and do not require additional training.

Acrylic plaster
Specifications:

• increased resistance to mechanical stress;
• moisture resistance;
• high adhesion to various surfaces.

silicate plaster mixes

The basis of silicate mixtures is potassium liquid glass. Silicate mixtures are produced in liquid form, ready for use. This type of mixture is ideal for finishing walls insulated with mineral wool.

silicate plaster
Specifications:

• excellent elasticity;
• good water resistance;
• good strength.

Silicone plaster mixes

As you can easily guess from the name, the composition of this type of mixture includes an expensive material - silicone. For this reason, silicone mixtures are very expensive, but the price is well compensated by the merits of this material.

silicone plaster
Specifications:

• excellent resistance to moisture;
• long-term operation;
• excellent adhesion;
• high elasticity;
• easy installation.

We examined the main types of plaster for walls, ceilings and facades. We advise you to carefully study the characteristics of each of them and choose the most suitable option. You can either buy a ready-made mixture, or cook it yourself according to the proportions above.

For leveling and finishing the 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 indoors or outdoors from +5 to +25 C. Also, the time for complete drying of the solutions is close in value (indoors at an air humidity of no 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;
• the surface is smoother, experienced craftsmen bring the finish 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 of 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 a high 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:

• fear high humidity, upon contact with water, 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, adding water to the solidified mixture will not restore desired properties plaster, the coating will turn out to be fragile.

Where applicable

Cement plaster is used for:

• internal or external work in any premises, even in unheated and damp ones, including basements, utility blocks, garages, porches, 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 of concrete structures, in order to increase 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 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 applying cement plaster over a plaster wall is a 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 intended for indoor areas 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. With large volumes of work, it is easier if experienced craftsmen do the finishing.
• Gypsum plasters are easier to apply. Their main task is to finish the inside of 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.

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

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

What kind of plaster better fit plaster or cement, should be decided in each case individually. Properly selected quality composition will 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

Plastered surface ready for finishing

Plaster mortar has various applications. The most obvious are:

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

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.

Quality criterion	Gypsum	Cement
Base material	gypsum	cement
with manual application	10	17
with mechanized	8	12,5
Drying time	up to 7 days	up to 4 weeks
Shrinkage	No	1 - 2 mm/m

Characteristics of the cement mixture

cement mixtures have high adhesion to the base

It is difficult to overestimate the convenience and optimality of cement plaster; this type of solution enjoys well-deserved popularity among both experienced craftsmen, and for 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 the effects of 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.

The main disadvantage of cement mortar is 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.

Engage in plastering at positive temperatures

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. High-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.

Slightly higher price tag than cement mortars, which counts against the fact that there is no need to use putty.

Preparation of solutions

Dry ingredients are mixed first, then water is added.

It is not enough just to choose 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.